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Last Updated :2024/11/08

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Master

Affiliation (Master)

  • Faculty of Engineering　Civil Engineering　Advanced Social System

Affiliation (Master)

  • Faculty of Engineering　Civil Engineering　Advanced Social System

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Profile and Settings

Degree

  • Ph. D.（University of New Brunswick, Graduate School）
  • (BLANK)（Hokkaido University）

Profile and Settings

  • Name (Japanese)

    SUGIYAMA

  • Name (Kana)

    TAKAFUMI

  • Name

    200901089887468094

Achievement

Research Interests

  • コンクリート   Concrete   

Research Areas

  • Social infrastructure (civil Engineering, architecture, disaster prevention) / Civil engineering (materials, implementation, construction management)

Research Experience

  • 2006 - Today Hokkaido University Professor
  • 1997 - 2006 Gunma University Associate Professor
  • 1994 - 1997 Gunma University Assistant Professor

Education

  • 1990 - 1994  University of New Brunswick  Graduate School, Division of Engineering  Civil Eng.
  • 1986 - 1990  Hokkaido University
  • 1982 - 1986  Hokkaido University  School of Engineering  Department of Civil Engineering

Awards

  • 2019 日本コンクリート工学会賞 功労賞
     
    受賞者: 杉山 隆文
  • 2014 日本コンクリート工学会賞 論文賞
     
    受賞者: 杉山 隆文
  • 2013 セメント協会論文賞
     
    受賞者: 杉山 隆文
  • 2006 日本コンクリート工学協会賞 論文賞
     
    受賞者: 杉山 隆文
  • 2003 セメント協会論文賞

Published Papers

  • Rei YOSHIHARA, Kota NAKASE, Katsufumi HASHIMOTO, Takafumi SUGIYAMA, Yoshiki HONDA
    Journal of the Society of Materials Science, Japan 73 (10) 785 - 792 0514-5163 2024/10/15
  • Kota Nakase, Katsufumi Hashimoto, Takafumi Sugiyama, Katsuya Kono
    Construction and Building Materials 438 137019 - 137019 0950-0618 2024/08
  • Rei Yoshihara, Kota Nakase, Katsufumi Hashimoto, Takafumi Sugiyama, Yoshiki Honda
    Buildings 14 (4) 1132 - 1132 2024/04/17 
    The mechanical performance of a printed object in 3D concrete printing is influenced by the interfacial bonding strength between the deposited filaments. Hence, the physical properties of the layer interface and the influential factors have been studied. This study aims to clarify the mechanism of aggregate distribution heterogeneity as well as the influence of printing material extrusion speed on the heterogeneity inside the filament. A laboratory-scale material extruder is developed and used in this study. The aggregate distribution is evaluated in a quantitative manner with the cross-sectional image obtained by X-ray computed tomography. The images were taken in the deposited filament and the material extrusion nozzle for printing. Results show that large aggregate moves from the outside of the printing nozzle toward the center with increasing extrusion speed from 1.8 to 7.1 mm/s. As extrusion speed increases, it is inferred that a lubrication layer forms on the inner surface of the nozzle, causing the transition of material extrusion behavior from laminate flow to plug flow. Thus, the aggregate distribution appears differently inside the filament. This finding indicates that the magnitude of friction against the nozzle wall alters the die swell during discharge as well as the aggregate distribution before and after extrusion.
  • Christian Orozco, Sandhya Babel, Somnuk Tangtermsirikul, Takafumi Sugiyama
    Sustainable Materials and Technologies 39 e00796 - e00796 2214-9937 2024/04 [Refereed]
  • Kota Nakase, Katsufumi Hashimoto, Takafumi Sugiyama, Katsuya Kono
    Concrete Research and Technology 35 13 - 23 1340-4733 2024
  • Christian Orozco, Somnuk Tangtermsirikul, Takafumi Sugiyama, Sandhya Babel
    Scientific Reports (Springer Nature) 13 (1) 2023/10/25 [Refereed]
     
    Abstract Fly ash has been widely used as a cement substitute to improve the sustainability of concrete. Although the advantages of fly ash have been extensively documented, there is a gap in understanding why its use in mass concrete applications remains low in some countries, such as the Philippines. Thus, this work aims to understand the issues that impede waste utilization, particularly fly ash in the concrete construction industry, quantify the impact of the current practice, and identify opportunities for sustainable fly ash utilization. Endpoint impact analysis was conducted through the life cycle using SimaPro 9.3 to quantify the impacts on human health, ecosystem, and resources of 31 concrete mixtures of low, normal, and high strength design with 0 to 20% fly ash as cement replacement. In-depth, semi-structured interviews with key stakeholders were undertaken to determine the institutional, economic, social, and technological challenges related to the utilization of waste materials in large-scale concrete construction. More than 90% of the total impact of concrete contributes to damage to human health, primarily caused by global warming and fine particulate matter. The use of fly ash at 20% replacement by weight of cement benefits resources more significantly than human health and the ecosystem. The use of chemical admixture to improve strength has a significant impact on resources. High fly ash replacement for normal and high-strength concrete has a greater reduction in all endpoint categories than for low-strength design. Recommendations are proposed to maximize the beneficial impact of using fly ash in the concrete industry.
  • Christian R. Orozco, Somnuk Tangtermsirikul, Takafumi Sugiyama, Sandhya Babel
    Environmental Research 234 0013-9351 2023/10 [Refereed]
  • Yingyao Tan, Takafumi Sugiyama, Katsufumi Hashimoto
    16th International Conference on Durability of Building Materials and Components 2023/10 [Refereed]
  • Evaluation of transport properties in ITZ with coupled CT image analysis and simulation
    Yingyao Tan, Takafumi Sugiyama, Katsufumi Hashimoto
    16th International Congress on the Chemistry of Cement 2023 (ICCC2023) III 229 - 232 2023/09 [Refereed]
  • Ni Wang, Takafumi Sugiyama
    Magazine of Concrete Research 75 (9) 433 - 446 0024-9831 2023/05 [Refereed][Not invited]
     
    One of the challenges to reinforced concrete slabs in bridges is deterioration due to rebar corrosion by deicing salts. In order to simulate a concrete slab subjected to deicing salt penetration from the top surface of the bridge slab during winter, high-strength steam-cured concrete with double-layer reinforcements was exposed to 10% sodium chloride solution to investigate rebar corrosion. Five concrete mix proportions were prepared, including high early strength concrete and concrete containing fly ash and blast furnace slag as supplementary cementitious materials (SCMs). For both the high early strength and fly ash concretes, alkali active andesite in the pessimum proportion was mixed with coarse aggregates to investigate the effect of alkali–silica reaction (ASR) on rebar corrosion. It was found that the combined effects of chloride attack and ASR adversely affected the corrosion resistance of high early strength concrete. Fly ash concrete had excellent performance as to corrosion resistance and ASR mitigation. Results also showed that a widely used electrochemical technique known as the half-cell potential test can satisfactorily diagnose corrosion of double-layer reinforced concrete. Concrete specimens containing SCMs with no ASR threat showed no signs of steel bar corrosion and significantly low chloride diffusion coefficients after 3 years.
  • Yingyao Tan, Takafumi Sugiyama, Katsufumi Hashimoto
    Construction and Building Materials 369 130526 - 130526 0950-0618 2023/03 [Refereed]
  • Characterizing porosity and component change of hardened cement paste deteriorated by leaching with non-destructive integrated CT-XRD method,
    Tan Yingyao, Anna Tomo, Takafumi Sugiyama, Katsufumi Hashimoto
    76th RILEM Annual Week and International Conference on Regeneration and Conservation of Structures (ICRCS2022) 2022/09
  • Takafumi Sugiyama, Michael Angelo B. Promentilla
    Journal of Advanced Concrete Technology 19 (6) 730 - 755 1346-8014 2021/06/25 [Refereed]
  • N. Wang, A. Cahyadi, T. Sugiyama
    Bridge Maintenance, Safety, Management, Life-Cycle Sustainability and Innovations, CCR Press 4137 - 4143 2021/04/19 [Refereed]
  • Evaluation of Interfacial Transition Zone in Concrete by Synchrotron Radiation Microtomography
    Hiroaki HASEBE, Akio CHIMOTO, Takafumi SUGIYAMA
    Proceedings of the 6th International Conference on Construction Materials (ConMat’20) 755 - 765 2020/09 [Refereed]
  • Investigation of the effect of aggregate types on cracking due to high temperature by non-destructive integrated CT-XRD method
    Takahashi H, Mikami T, Chimoto A, Sugiyama T
    Proceedings for 3rd ACF Symposium 2019: Assessment and Intervention of Existing Structures 2019/09 [Refereed]
  • Effect of steam curing on chloride ion penetration resistance of concrete with supplementary cementitious materials in the marine environment
    Wang N, Iyoda G, Sugiyama T
    Proceedings for 3rd ACF Symposium 2019: Assessment and Intervention of Existing Structures 2019/09 [Refereed]
  • Corrosion evaluation with electro-chemical technique on steel embedded in reinforced concrete slab for road bridge
    Cahyadi A, Sugiyama T
    Proceedings for 3rd ACF Symposium 2019: Assessment and Intervention of Existing Structures 2019/09 [Refereed]
  • Experimental study of slag gypsum cement concrete to recycle waste gypsum board
    Ryo Suzuki, Kazunori Shimura, Takafumi Sugiyama
    Proceedings for 1ST International Conference on Innovation in Low-Carbon Cement & Concrete Technology 2019/06/24 [Refereed][Not invited]
  • T.B.T.Nguyena, R.C.Warangkana, S.Tangtermsirikula, T. Sugiyama
    Construction and Building Materials 209 176 - 186 2019 [Refereed][Not invited]
  • H. Takahashi, T. Sugiyama
    Construction and Building Materials 203 579 - 588 2019 [Refereed][Not invited]
  • Study on Frost Resistance of Fly Ash and Blast Furnace Slag Concrete with Steam Curing
    N., Wang, Y. Hou, T. Sugiyama
    Proceedings on 8th International Conference of Asian Concrete 2 695 - 700 2018/11 [Refereed][Not invited]
  • 非破壊CT-XRD連成法を利用した高温を受けたモルタルの変質およびひび割れに関する考察
    高橋駿人, 三上拓也, 杉山隆文
    コンクリート工学年次論文集 40 (1) 307 - 312 2018/07 [Refereed][Not invited]
  • Investigation of microstructure of cementitious material exposed to high temperature by non-destructive integrated CT-XRD method
    T. Mikami, H. Takahashi, T. Sugiyama
    Proceedings of Sixth International conference on Durability of Concrete Structures 562 - 565 2018/07 [Refereed][Not invited]
  • Idrees Zafar, Takafumi Sugiyama
    Construction and Building Materials 160 293 - 307 0950-0618 2018/01/30 [Refereed][Not invited]
     
    In the present study an effort was made to clarify the performance of pre-cracked fly ash concrete against corrosion under different exposure conditions. A total of twenty specimens from two different concrete mixes were tested against three different exposure conditions for 106 days. It was observed that the crack filling ability of concrete is more sensitive to crack width than fly ash replacement and exposure conditions. Under submerged conditions the fly ash concrete showed greater pitting corrosion, while under wet and dry cycle conditions, the corrosion damage was found to be less penetrating as compared to normal Portland cement concrete.
  • Idrees Zafar, Takafumi Sugiyama
    Construction and Building Materials 160 293 - 307 0950-0618 2018/01/30 [Refereed][Not invited]
     
    In the present study an effort was made to clarify the performance of pre-cracked fly ash concrete against corrosion under different exposure conditions. A total of twenty specimens from two different concrete mixes were tested against three different exposure conditions for 106 days. It was observed that the crack filling ability of concrete is more sensitive to crack width than fly ash replacement and exposure conditions. Under submerged conditions the fly ash concrete showed greater pitting corrosion, while under wet and dry cycle conditions, the corrosion damage was found to be less penetrating as compared to normal Portland cement concrete.
  • Study on Corrosion of RC Slab with Partial Replacement of Cement as Fly Ash Using Nondestructive Testing Method
    S. D. Gupta, T. Sugiyama
    Proceedings of 8th Asia and Pacific Young Researchers and Graduates Symposium (YRGS 2017) 2017/09 [Refereed][Not invited]
  • X線CT法を用いた引張力を受けた異形鉄筋周辺のひび割れに関する観察
    高橋駿人, 志村和紀, 杉山隆文, 田中大之
    コンクリート工学年次論文集 39 (1) 307 - 312 2017/07 [Refereed][Not invited]
  • T. Sugiyama, J. C. Kuri
    SPring-8/SACLA利用研究成果集 (SPring-8/SACLA Research Report) (5) 100 - 104 2017 [Refereed][Not invited]
  • Investigation of alteration in deteriorated mortar due to water attack using non-destructive integrated CT-XRD method
    H. Takahashi, T. Sugiyama
    Proceedings of 11th fib International Ph.D. Symposium in Civil Engineering 445 - 451 2016/08 [Refereed][Not invited]
  • 自然電位法および分極抵抗法を用いたRC床板内に2段配筋された鉄筋の腐食診断についての実験的考察
    桃野英太郎, Idrees Zafar, 杉山隆文
    コンクリート工学年次論文集 38 (1) 1239 - 1244 2016/07 [Refereed][Not invited]
  • 非破壊CT-XRD連成法を用いた流水によるセメント硬化体ひび割れ近傍の溶脱現象の観察
    菊池玲子, 高橋駿人, 杉山隆文
    コンクリート工学年次論文集 38 (1) 1095 - 1100 2016/07 [Refereed][Not invited]
  • X線CT法を用いた鉄筋埋設モルタルのひび割れおよび電食試験による腐食鉄筋の観察
    高橋駿人, 志村和紀, 杉山隆文, 田中大之
    コンクリート工学年次論文集 38 (1) 2163 - 2168 2016/07 [Refereed][Not invited]
  • Michael Angelo B. Promentilla, Shermaine M. Cortez, Regina Anne D. C. Papel, Bernadette M. Tablada, Takafumi Sugiyama
    MATERIALS 9 (5) 388  1996-1944 2016/05 [Refereed][Not invited]
     
    Pore structure, tortuosity and permeability are considered key properties of porous materials such as cement pastes to understand their long-term durability performance. Three-dimensional image analysis techniques were used in this study to quantify pore size, effective porosity, tortuosity, and permeability from the X-ray computed tomography (CT) images of deteriorated pastes that were subjected to accelerated leaching test. X-ray microtomography is a noninvasive three-dimensional (3D) imaging technique which has been recently gaining attention for material characterization. Coupled with 3D image analysis, the digitized pore can be extracted and computational simulation can be applied to the pore network to measure relevant microstructure and transport properties. At a spatial resolution of 0.50 mu m, the effective porosity (phi(e)) was found to be in the range of 0.04 to 0.33. The characteristic pore size (d) using a local thickness algorithm was found to be in the range of 3 to 7 mu m. The geometric tortuosity (tau(g)) based on a 3D random walk simulation in the percolating pore space was found to be in the range of 2.00 to 7.45. The water permeability values (K) using US NIST Permeability Stokes Solver range from an order of magnitudes of 10(-14) to 10(-17) m(2). Indications suggest that as effective porosity increases, the geometric tortuosity increases and the permeability decreases. Correlation among these microstructure and transport parameters is also presented in this study.
  • Michael Henry, Katsufumi Hashimoto, Ivan Sandi Darma, Takafumi Sugiyama
    JOURNAL OF ADVANCED CONCRETE TECHNOLOGY 14 (4) 134 - 143 1346-8014 2016/04 [Refereed][Not invited]
     
    Water re-curing of fire-damaged concrete may reduce the environmental and economic impacts of repair operations by re-using the existing concrete. To clarify the rehydration mechanism, the effects of water re-curing on the microstructure and chemical properties of fire-damaged cement paste were examined. Analysis by X-ray CT showed that heating led to radial cracks that propagated horizontally and vertically in the cement paste specimen. Water supply led to a growth in the cracked space through an increase in the connectivity of the crack network. This growth may be due to expansion caused by the rehydration of CaO into Ca(OH)(2). Chemical analyses suggest that the rehydration reaction differs from the initial hydration in that C2S plays a greater role in generating C-S-H gel during the earlier period of water re-curing.
  • Pore structure analysis of mortar under freeze-thaw cycles using X-Ray computed tomography
    Katsufumi Hashimoto, Hiroshi Yokota, Takafumi Sugiyama
    Sustainable Construction Materials and Technologies 2016- 2515-3056 2016 
    Frost damage due to freeze thaw action of pore water in concrete is an important issue on durability of concrete structures in cold regions. It is generally known that different temperature histories in freeze-thaw cycles affect scaling of concrete, in which the pore structure might be changed due to propagation of micro cracks. In previous research, 3D images from X-ray computed tomography have been used to analyze the pore structure of concrete. This study aimed to evaluate the pore structure of mortar under freeze-thaw cycles with different temperature histories by using X-ray computed tomography, evaluating and detecting the alteration of pore structure and discuss their influences on permeability degradation. As the results, 1) the temperature histories gave different progress of residual strain and void distributions alteration, in which decrease behavior of tortuosity and spacing factor were able to be explained using residual strain due to frost damage 2) propagation of micro cracks due to frost damage probably increased spacing factors and tortuosity calculated from information obtained in the analysis using X-ray computed tomography and 3) tortuosity and spacing factor linearly correlated with diffusion coefficient although void ratio did not correlated with diffusion coefficient.
  • Sugiyama T., Inoue M., Onodera O., Sawamura S.
    Concrete Journal 公益社団法人 日本コンクリート工学会 54 (9) 907 - 913 0387-1061 2016
  • Application of X-ray CT to the Observation of Cracking in a Corroded RC Bridge Slab
    J.C. Kuri, I. Zafar, T. Sugiyama
    Proceedings of 2nd International Conference on Tomography of materials and Structures (ICTMS 2015) 583 - 587 2015/06 [Refereed][Not invited]
  • Non-destructive Integrated CT-XRD Method Developed for Hardened Cementitious Material
    T. Sugiyama, T. Hitomi, K. Kajiwara
    Proceedings of 2nd International Conference on Tomography of materials and Structures (ICTMS 2015) 560 - 564 2015/06 [Refereed][Not invited]
  • Investigation on Cracked Cement Paste Subjected to Water Flow by Non-destructive Integrated CT-XRD Method
    Jhutan Chandra Kuri, Takafumi Sugiyama, Takashi Hitomi, Kentaro Kajiwara
    Proceedings of International Conference on the Regeneration and Conservation of Concrete Structures (RCCS)、Japan Concrete Institute, Nagasaki, Japan、June 1-3, 2015 2015/06 [Refereed][Not invited]
  • Sugiyama T.
    Concrete Journal 公益社団法人 日本コンクリート工学会 53 (12) 1027 - 1027 2015
  • I. Zafar, T. Sugiyama
    LIFE-CYCLE OF STRUCTURAL SYSTEMS: DESIGN, ASSESSMENT, MAINTENANCE AND MANAGEMENT 1538 - 1543 2015 [Refereed][Not invited]
     
    The corrosion state of the reinforcement in concrete containing various proportions of fly ash was analyzed within specified limits of corrosion current density (0.5-1.0 mu A/cm(2)). The reinforced concrete specimens were subjected to 10% NaCl solution to de-passivate the reinforcement bars. Activation polarization was found to be the governing mechanism of rebar corrosion irrespective of the fly ash addition. It was perceived that the longer curing for fly ash concrete has delayed the onset of the corrosion of rebars but on the other hand it has increased the probability of pitting corrosion.
  • X線CT法を利用した気泡分布測定
    高橋駿人, 土生侑佑, 志村和紀, 杉山隆文
    JCI-C86、「コンクリート中の気泡の役割・制御に関する研究委員会」シンポジウム 59 - 64 2015 [Refereed][Not invited]
  • Experimental Factors with regard to Increased Corrosion Resistance in Fly Ash Concrete
    Idrees Zafar, Takafumi Sugiyama
    Proceedings of EURO COAL ASH 2014 251 - 264 2014/11 [Refereed][Not invited]
  • Study on the effect of Bending Crack on Corrosion of Rebars in Fly Ash Concrete
    Idrees Zafar, Takafumi Sugiyama
    Proceedings of 6th International Conference of Asian Concrete Federation, ACF 2014 1111 - 1113 2014/09 [Refereed][Not invited]
  • Michael Henry, Ivan Sandi Darma, Takafumi Sugiyama
    CONSTRUCTION AND BUILDING MATERIALS 67 37 - 46 0950-0618 2014/09 [Refereed][Not invited]
     
    Microstructure recovery plays an important role in restoring the performance of concrete damaged by fire. This research applied X-ray CT and image analysis techniques to non-destructively examine the internal microstructure of high-strength concrete in order to clarify the effects of heating and re-curing on microstructure characteristics. Heating caused an increase in total pore space due to an increase in connectivity caused by the formation of cracks in the mortar-aggregate interface and bridging cracks. Water re-curing, however, was effective in recovering microstructure through the reduction in connected pore space, with most recovery occurring within 7 days. (C) 2013 Elsevier Ltd. All rights reserved.
  • M. Henry, T. Sugiyama, I. S. Darma
    Proceedings of 4th International Conference on the Durability of Concrete Structures 206 - 211 2014/07 [Refereed][Not invited]
  • T. Sugiyama, T. Hitomi, K. Kajiwara
    Proceedings of 4th International Conference on the Durability of Concrete Structures 298 - 303 2014/07 [Refereed][Not invited]
  • Idrees Zafar, Takafumi Sugiyama
    MAGAZINE OF CONCRETE RESEARCH 66 (20) 1051 - 1064 0024-9831 2014 [Refereed][Not invited]
     
    The objective of this study is to detect reliably the onset of corrosion in fly ash concrete using an embedded reference electrode. The half-cell potential of rebars in fly ash concrete subjected to 10% sodium chloride solution is monitored using an embedded reference electrode and an alternating current impedance spectroscope, along with other impedance parameters such as polarisation resistance and specific concrete resistance. At initiation of corrosion, the values of chloride threshold levels are obtained and the effect of long curing for fly ash concrete on chloride threshold values is analysed. The combination of two corrosion monitoring systems allows the estimation of corrosion initiation in fly ash concrete. It is found that chloride threshold values for fly ash concrete given a longer curing period approach the values for Portland cement concrete. Probabilistic analysis of the experimental data is carried out to find a best-fit probability distribution for time to initiate corrosion and chloride threshold values of fly ash concrete.
  • Ivan Sandi Darma, Takafumi Sugiyama, Michael Angelo B. Promentilla
    JOURNAL OF ADVANCED CONCRETE TECHNOLOGY 11 (10) 266 - 281 1346-8014 2013/10 [Refereed][Not invited]
     
    This paper demonstrates the application of microfocus X-ray computed tomography (CT) to study solute transport in cracked concrete. Cracks in a cylindrical specimen of ordinary Portland cement (OPC) and fly ash mortar were induced using a splitting tensile test. Cesium Carbonate (Cs2CO3) was then used as a tracer in the in-situ diffusion test with the aid of X-ray CT. Image analysis was also employed to measure the 3D crack geometry and tracer diffusivity from these CT images. The geometric tortuosity of the crack was approximately 1.25 irrespective of the crack opening width and whether fly ash was added or not. On the other hand, the constrictivity increased for the fly ash mortar having roughly the equivalent crack opening width. The measured diffusivity in the crack was controlled by both crack opening width and constrictivity. Results obtained from microtomographic images suggest that the entire crack space may not always be filled with the tracer. The diffusive transport of solute in cracks thus can be restricted from microstructure's point of view. Smaller crack opening would increase such restricted diffusion. Indications also suggest that the addition of fly ash would lead to the reduction of diffusivity through uncracked body of the mortar.
  • Katsufumi Hashimoto, Hiroshi Yokota, Takafumi Sugiyama, Takasumi Kikkawa
    Zairyo/Journal of the Society of Materials Science, Japan 62 (8) 492 - 497 0514-5163 2013/08 [Refereed][Not invited]
     
    Frost damage due to freeze thaw action of pore water in concrete is an important issue on durability of concrete structures in cold regions. It is generally known that different temperature histories in freeze-thaw cycles affect scaling of concrete, in which the pore structure might be changed due to propagation of micro cracks. In previous research, 3D images from X-ray computed tomography have been used to analyze the pore structure of concrete. This study aimed to evaluate the pore structure of mortar under freeze-thaw cycles with different temperature histories by using X-ray computed tomography. As the results, 1) the temperature histories gave different progress of residual strain and void distributions, in which decrease of toutuosity and spacing factor were shown with more residual strain due to frost damage 2) propagation of micro cracks due to frost damage probably increases spacing factors and tortuosity calculated from information obtained in analysis using X-ray computed tomography and 3) tortuosity and spacing factor linearly correlated with diffusion coefficient although void ratio did not correlated with diffusion coefficient Thus, this study showed that pore connectivity informed from tortuosity and spacing factor evaluated by X-ray computed tomography, in addition to pore structural indicators such as total pore volume, were reasonably discussed with progress of frost damage and alteration of diffusion coefficient. © 2013 The Society of Materials Science, Japan.
  • Durability of fly ash concrete in salt-laden environment
    SUGIYAMA TAKAFUMI
    3rd International Conference on Sustainable Construction Materials and Technology 19 - 24 2013/08 [Refereed][Not invited]
  • M. A B Promentilla, T. Sugiyama
    Advances in Computed Tomography for Geomaterials: GeoX 2010 124 - 131 2013/01/21 [Refereed][Not invited]
     
    This paper presents a methodology to investigate the damage process in cementbased materials that have been subjected to freezing and thawing action. The microfocus xray computed tomography (CT), a non-destructive and non-invasive imaging technique, allows us to examine the cracks in the damaged mortar at a resolution of the order of 10 micrometers. Image processing and analysis of the microtomographic images are also applied to gain three-dimensional (3D) information of the internal microstructure. This information can be used to quantify the damage parameters on the basis of the 3D characterization of cracks in the damaged mortar. Representative samples of the analyzed volumetric data are presented to demonstrate the feasibility of the proposed method. © ISTE Ltd 2010.
  • Analysis of cracking in high-strength cementitious materials under heating and re-curing using X-ray CT
    Michael Henry, Ivan Sandi Darma, Yuto Haraguchi, Takafumi Sugiyama
    Sustainable Construction Materials and Technologies 2013- 2515-3056 2013 
    The healing of cracks formed during high temperature exposure plays an important role in the performance recovery of concrete damaged by fire, but it is necessary to better understand the cracking behavior under heating and re-curing. This research applied X-ray microtomography and image analysis techniques to non-destructively examine the internal microstructure of high-strength cementitious materials and to clarify the changes in crack characteristics due to heating and water re-curing. Results showed that, in cement paste, radial cracks formed during heating due to shrinkage by dehydration and these cracks grew larger and new cracks formed during re-curing due to expansion by rehydration. In concrete, cracks formed around aggregates due to incapability in thermal expansion, but water re-curing reduced the total crack space. Better crack recovery in concrete relative to cement paste may be due to the lower cement content and the restraining effect of aggregates.
  • M. Henry, T. Sugiyama, T. Iyoda, K. Sato
    Proceedings of the 13th East Asia-Pacific Conference on Structural Engineering and Construction, EASEC 2013 2013 [Refereed][Not invited]
     
    The use of low quality recycled aggregates in concrete reduces performance and increases variation. Therefore, it is important to examine the performance and safety of concrete using low quality recycled aggregates from a variety of perspectives. This study applied X-ray CT and image analysis to examine the structure of recycled aggregates in order to explore how X-ray CT may be applied to recycled aggregate concrete. It was found that recycled aggregates from different sources showed widely varying X-ray CT absorption values, which makes it difficult to carry out further analyses unless there are clear differences in the material phases. However, it is possible to estimate the amount of residual mortar through segmentation between the solid and void phases.
  • 池田昇平, 杉山隆文, 吉川昴純, 志村和紀
    コンクリート構造物の補修,補強,アップグレード論文報告集 12 207 - 214 1346-7492 2012/11 [Refereed][Not invited]
  • DARMA Ivan S, SUGIYAMA Takafumi, HITOMI Takashi, SHIMURA Kazunori
    コンクリート工学年次論文集(CD-ROM) 34 (1) 202 - 207 1347-4111 2012/06 [Refereed][Not invited]
  • 古村惇朗, 杉山隆文
    コンクリート工学年次論文集(CD-ROM) 34 (1) 1012 - 1017 1347-4111 2012/06 [Refereed][Not invited]
  • 吉川昂純, 杉山隆文, DARMA Ivan sandi, 志村和紀
    コンクリート工学年次論文集(CD-ROM) 34 (1) 1810 - 1815 1347-4111 2012/06 [Refereed][Not invited]
  • 杉山隆文
    月刊地球 海洋出版 34 (3) 180 - 185 0387-3498 2012/03 [Refereed][Not invited]
  • HASHIMOTO KATSUFUMI, YOKOTA HIROSHI, SATO YASUHIKO, SUGIYAMA TAKAFUMI
    セメント・コンクリート論文集 Japan Cement Association 65 (65) 400 - 405 0916-3182 2012/02 [Refereed][Not invited]
     
    Frost damage, which is the deterioration due to freeze and thaw of pore solution is causes scaling, pop-out and cracks on surface of concrete members, is an important issue in the durability of concrete structures in cold regions. Deicing agents are sprayed in order to prevent frost damage. By contrast, it has been reported that chlorides of deicing agents accelerate the deterioration due to frost damage under freeze-thaw environment. It is generally known that phase changes of hydration products, such as formation of friedel's salt and ettringite, occur due to penetration of chloride ion. Ettringite formation leads volume expansion and cracks. Since the acceleration of frost damage due to chlorides penetration, the use of deicing agents which is not containing chloride ions, such as potassium acetate and calcium-magnesium acetate, has been proposing. However, it has not been shown that chemical alteration due to penetration of deicing agents influence on increase of strain and decrease of structural characteristic value with frost damage under freeze-thaw environment. Therefore, this study aimed to investigate the influence of deicing agents under freeze-thaw environment on 1）progress of frost damage, 2）phase changes of hydration products and 3）decrease of structural characteristic value. As the results, 1）penetration of deicing agents containing chloride ions influenced on the strain hysteresis and resulted in the increase of residual strain and water absorbing ratio, 2）ettringite formation with displacement and dissolution of monosulfate hydrates was a contributory factor for frost damage acceleration and 3）chemical alteration and increase of residual strain due to penetration of chlorides led decrease of tensile strength, elastic modulus and fractural energy.
  • 池上裕樹, 杉山隆文
    コンクリート工学年次論文集(CD-ROM) 33 (1) 1859 - 1864 1347-4111 2011/06 [Refereed][Not invited]
  • T. Sugiyama, M. A. B. Promentilla, T. Hitomi, N. Takeda
    CEMENT AND CONCRETE RESEARCH 40 (8) 1265 - 1270 0008-8846 2010/08 [Refereed][Not invited]
     
    Deteriorated mortars and cement pastes (w/c = 0.50) were prepared by an accelerated leaching test using electrochemical migration technique. This technique enabled the reduction of the CaO/SiO(2) molar ratio to less than 2.0. Non-destructive three-dimensional imaging of the internal microstructure of the deteriorated cement matrix in hardened cement paste and mortar was performed using synchrotron X-ray computed microtomography at SPring-8. Japan. After image analysis at a spatial resolution of 0.5 mu m/voxel the microtomographic images successfully visualized increased pore spaces in the deteriorated cement matrix with the effective porosity ranging from 0.31 to 0.38. In addition the diffusion tortuosity in the pore space derived from random walk simulation was also evaluated as a pore structure-transport parameter. Indications suggest that the deterioration of the cement matrix due primarily to the dissolution of portlandite decreases the diffusion tortuosity to a single digit as the degree of pore connectivity becomes larger at the submicron scale. (C) 2009 Elsevier Ltd. All rights reserved.
  • Michael Angelo B. Promentilla, Takafumi Sugiyama
    JOURNAL OF ADVANCED CONCRETE TECHNOLOGY 8 (2) 97 - 111 1346-8014 2010/06 [Not refereed][Not invited]
     
    This paper presents our findings on the application of X-ray microtomography to characterize the internal structure of mortars that were exposed to freezing-thawing action. A microfocus X-ray CT (micro-CT) scanner was used for the nondestructive 3D imaging of internal air voids or cracks at a spatial resolution of the order of 10 microns. Four different types of mortar specimens (i.e., non-air-entrained and air-entrained Portland cement mortar, and non-air-entrained and air-entrained fly ash mortar) were scanned after being subjected to different numbers of freeze-thaw cycles. Coupled with image analysis, the void space obtained from micro-CT was characterized in three dimensions (3D) in terms of void fraction and air void size distribution, as well as, the crack width and tortuosity of the connected crack network. Results suggest that the initial air voids follow a lognormal distribution with the highest population of modal size around 30-50 mu m, irrespective of the type of mortar. As the distributed air voids of non-air entrained mortars were relatively few in numbers, the fly ash mortar in particular was the least resistant against frost damage as shown by the formation of internal cracks that meander around the weaker paste-aggregate interface. Indications also suggest that these cracks are well connected and anisotropic in 3D.
  • 増田亜由子, PROMENTILLA Michael Angelo B, 杉山隆文
    コンクリート工学年次論文集(CD-ROM) 32 (1) 539 - 544 1347-4111 2010/06 [Refereed][Not invited]
  • Hiroki Ikegami, Michael Angelo B. Promentilla, Takafumi Sugiyama
    ADVANCES IN CONCRETE STRUCTURAL DURABILITY: PROCEEDINGS OF THE 2ND INTERNATIONAL CONFERENCE ON DURABILITY OF CONCRETE STRUCTURES ICDCS2010 97 - 106 2010 [Refereed][Not invited]
     
    This paper discusses our findings on the use of microfocus X-ray computed tomography (CT) to determine the air void size distribution in fly ash mortar and concrete. The presence of air voids in such materials has been known to play an important role in the frost durability of concrete structures. It is therefore important to determine not only the quantity of the air voids present, but also the quality of this air void system in fly ash concrete. With the use of microfocus X-ray CT, we can examine the internal structure of specimens without any laborious cross-section preparation that is typically required of two-dimensional (2D) microscopy. Accordingly, the technique of X-ray microtomography allows us to do a nondestructive and noninvasive three-dimensional (3D) imaging of the microstructure at a spatial resolution of few order of micrometers. After image acquisition from the microfocus X-ray CT, a number of image analysis routines such as segmentation and cluster labeling was applied to extract and identify the air voids from the CT images. The visualization of air voids in three dimensions including the corresponding air void size distribution from representative samples of the analyzed volumetric data was also presented.
  • Michael Angelo B. Promentilla, Takafumi Sugiyama
    ISCM II AND EPMESC XII, PTS 1 AND 2 1233 1378 - 1383 0094-243X 2010 [Refereed][Not invited]
     
    Cracking in cement-based materials such as mortar and concrete plays a major factor in the material's strength and durability. The crack tortuosity is therefore important to understand and model the effect of microstructure attributed to cracking on the transport properties of the material. This paper describes a method to identify the crack pattern from the microtomographic images and quantify its tortuosity by 3D image analysis and random walk simulation, respectively. The tortuosity is defined as the ratio of the self-diffusion coefficient of non-sorbing walkers in free space (no solids) to the long-time self-diffusion coefficient of these walkers in crack space. X-ray microtomography, a 3D nondestructive imaging technique, was used to examine the cracks in damaged mortar at a spatial resolution of the order of 10 micrometers. Results of the crack measurement in a mortar that was subjected to cyclic freezing-thawing environment were presented.
  • Pore space analysis and estimation of transport properties of deteriorated cementitious material using synchrotron microtomography
    Promentilla, M.A.B, T. Sugiyama, T. Hitomi, N. Takeda
    Proceedings of the 2nd International RILEM workshop on Concrete Durability and Service Life Planning (ConcreteLife 2009) 498 - 506 2009/09 [Refereed][Not invited]
  • Corrosion Monitoring Rebars in Concrete under Accelerated Chloride Environment
    G.M. S. Islam, T. Sugiyama
    Proceedings of 4th International Conferernce on Construction Materials; Performance, Innovation and Structural Implication 255 - 262 2009/08 [Refereed][Not invited]
  • M. A. B. Promentilla, T. Sugiyama, T. Hitomi, N. Takeda
    CEMENT AND CONCRETE RESEARCH 39 (6) 548 - 557 0008-8846 2009/06 [Refereed][Not invited]
     
    Tortuosity, as being influenced by the 3D pore micro-geometry, is an important physical quantity to understand better the effect of pore structure on transport properties of cement-based materials. This study attempts to evaluate directly this pore structure-transport parameter from the microtomographic images at spatial resolution of 0.5 mu m. This resolution, is by far, to our knowledge, the highest resolution reported for 3D non-invasive imaging of hardened cement pastes. The results show the feasibility of using synchrotron microtomography coupled with 3D image analysis and random walk simulation to measure the diffusion tortuosity that has a direct bearing on transport properties. The tortuosity associated with the percolating pore space seems to reflect the pore morphology that mainly controls the transport properties in young cement pastes; thus, explaining the rough agreement of the results with the computer model or experimental evidence. (c) 2009 Elsevier Ltd. All rights reserved.
  • Three dimensional characterization of air void system in cement-based materials
    Promentilla, M.A.B, Sugiyama, T, Shimura, K
    Proceedings of the 3rd Asian Concrete Federation (ACF) International Conference 2008/11 [Refereed][Not invited]
  • 杉山隆文, 志村和紀, PROMENTILLA Michael A. B, 畠田大規
    コンクリート構造物の補修,補強,アップグレード論文報告集 8 99 - 104 1346-7492 2008/10/31 [Not refereed][Not invited]
  • 鈴木健太, 杉山隆文, 川北昌宏, 志村和紀
    コンクリート工学年次論文集 日本コンクリート工学協会 30 (1) 849 - 854 1347-7560 2008/07/30 [Not refereed][Not invited]
     
    JIS II種灰を用いたフライアッシュコンクリートの塩分浸透性を6年半の室内塩水浸せき試験から調べた。また,JIS III種灰で作製したフライアッシュコンクリートを用いた護岸コンクリート構造物からコアを抜き,同様に塩分浸透性を調査した。実験では各供試体の全塩化物イオン濃度分布を求めた。また,電子線マイクロアナライザ(EP凧)から得られた特性X線強度分布曲線を解析した。塩分浸透に対するフライアッシュの効果を確認し,EP臥から予測した塩分浸透性は実験結果と比較的良く一致することがわかった。
  • Michael Angelo B. Promentilla, Takafumi Sugiyama, Takashi Hitomi, Nobufumi Takeda
    JOURNAL OF ADVANCED CONCRETE TECHNOLOGY 6 (2) 273 - 286 1346-8014 2008/06 [Not refereed][Not invited]
     
    Aside from porosity, the degree of pore connectivity and tortuosity are important pore structure characteristics of cement-based materials to understand better the effect of microstructure on transport processes that influence the durability of these materials. Synchrotron X-ray computed microtomography is employed to provide information about the three-dimensional (3D) pore structure at submicron resolution (0.5 mu m/voxel) using the SPring-8 facility in Hyogo, Japan. This paper presents a method to characterize the pore space of hardened cement pastes taken from different specimens of various ages (2, 7, and 28 days) of curing. By defining the pore threshold value on the basis of the transition point in the porosity-threshold dependency curve, the pores were distinguished from the solid matrix in the microtomographic images. Further, pore cluster multiple labeling was performed to gain information on the pore connectivity and the associated effective porosity. 3D random walk simulation in the largest percolating pore cluster was then conducted to evaluate the diffusion tortuosity. The results from this study provide indications of increasing diffusion tortuosity as pores that can be resolved by the X-ray imaging system decreased and became more disconnected. Sensitivity analysis to pore threshold value was performed to evaluate the robustness of the method.
  • WATANABE MASAKI, SUGIYAMA TAKAFUMI, TOMIZAWA NAOMI, TSUJI YUKIKAZU
    セメント・コンクリート論文集 (61) 351 - 357 0916-3182 2008/02/20 [Not refereed][Not invited]
  • T. Sugiyama, W. Ritthichauy, Y. Tsuji
    CEMENT AND CONCRETE RESEARCH 38 (1) 49 - 67 0008-8846 2008/01 [Refereed][Not invited]
     
    Chloride penetration and calcium dissolution have been investigated for a saturated concrete after exposure to a 0.5 mol/L NaCl solution for a period of up to 3150 days. Simultaneous ion transport model (SiTraM) that allows the transport of chloride and calcium ions to be simultaneously simulated in a hydrated cement system has been used to verify the experimental results. Self-compacting concrete (SCC) with a water to cement ratio of 0.3 resulted in a limited chloride penetration depth while the calcium dissolution was also reduced within the near surface zone. Increased unit water content for normal concrete resulted in higher chloride penetration depth and larger dissolution front of Ca(OH)(2) regardless of having the same water to cement ratio. It was revealed that the SiTraM can predict the profiles of chloride and calcium for self-compacting concrete. It was also found that the primary factor to control chloride penetration front and the dissolution front of Ca(OH)2 was the pore structure characteristic of concrete. (C) 2007 Elsevier Ltd. All rights reserved.
  • Takafumi, Sugiyama, Kenta, Suzuki, Masahiro, Kawakita, Kazunori, Shimura
    ADVANCES IN CONCRETE STRUCTURAL DURABILITY, PROCEEDINGS OF ICDCS2008, VOLS 1 AND 2 (1) 295 - 301 2008 [Refereed][Not invited]
     
    Chloride ingress in fly ash concrete was evaluated by the electron probe micro analysis (EPMA). Profile of characteristic X-ray strength for chlorine was obtained for fly ash concrete by EPMA and used to calculate apparent diffusion coefficient of chloride ions. A linear equation of characteristic X-ray strength and total concentration of chloride ions that was measured by a conventional acid extraction method was determined. Surface concentration of chloride ions was then determined. It was found that the profile of total concentration of chloride ions that was calculated with the apparent diffusion coefficient and surface concentration of chloride ions was comparable to experimental results. Fly ash concrete used for concrete breakwater structure showed higher resistance against chloride ingress after 6.75 years in service.
  • M. A. B. Promentilla, T. Sugiyama, K. Shimura
    MICROSTRUCTURE RELATED DURABILITY OF CEMENTITIOUS COMPOSITES, VOLS 1 AND 2 61 1357 - 1366 2008 [Refereed][Not invited]
     
    X-ray computed microtomography is now becoming a popular non-destructive method to study the microstructure of materials. As this technique operates on the same basic principle of medical computed tomography (CT) scanners, it provides the three-dimensional (3D) reconstruction of images from finite radiological images; but with much higher spatial resolution. For example, microfocus X-ray CT systems are now being designed to study the internal microstructure of specimen at spatial resolution of order of several microns. Furthermore, since the development of synchrotron as an X-ray source, advanced X-ray CT system is continually improving to approach spatial resolutions to submicron level. Such high-resolution technique is referred in this paper as X-ray tomographic microscopy (XTM) to highlight the distinction of this 3D imaging technique from the relatively well-established method of 2D microscopic imaging obtained from optical or electron microscope. This paper, therefore, demonstrates the use of XTM technique to investigate the microstructure of cement-based materials. The potentials for high resolution microtomographic images to understand the 3D microstructure of cement-based materials in relation to the durability performance of these materials are given. For instance, the application of synchrotron microtomography to examine the pore connectivity and tortuosity of the 3D pore space in hardened cement paste is presented. In addition, application of microfocus X-ray CT to characterize the air void system of air-entrained mortar is also described in this paper.
  • Takafumi Sugiyama, Yukikazu Tsuji
    PHYSICS AND CHEMISTRY OF THE EARTH 33 S276 - S284 1474-7065 2008 [Refereed][Not invited]
     
    In this research, a migration technique was applied to accelerate the migration of calcium ions from the pore solution of concrete so as to investigate the alteration of compacted bentonite in contact with the concrete. A 15 V of direct current was used for a composite specimen with 100 mm in diameter and 100 mm in length in which the electrical potential gradient was equal to 167 V/m. This composite consists of compacted bentonite (Na-type) sand mixture and concrete that is adjacent to each other. After a target Cumulative electric charge of 13 x 103 C was reached, the specimen was removed for analysis. The results of electron probe micro analyzer (EPMA) showed that the concentration of calcium became higher in the compacted bentonite in the vicinity of the interface with the concrete. This observation was supported by the results of thermogravimetry/differential thermal analysis (TG-DTA) that provided distinct evidences of reduced quantities of Ca(OH)(2) in the concrete in the vicinity of the interface with the compacted bentonite. Therefore, calcium ions migrated from the concrete to the compacted bentonite under the given electric field. The results of the X-ray diffraction (XRD) curves indicated possible transformation of the characteristic of the compacted bentonite. However depending on the mix proportions of concrete employed, altered characterization of the compacted bentonite was different. It was found that the swelling capacity of the compacted bentonite in contact with normal concrete was decreased to 64% of its initial swelling capacity as the ratio of calcium content to sodium content (Ca/Na) increased up to 3.7. On the other hand the swelling capacity of the compacted bentonite in contact with fly ash concrete was 85% of its initial swelling capacity with a ratio (Ca/Na) of 2.3. Accordingly the use of the electrical migration technique enables quantitative evaluation of the reduced swelling capacity of the compacted bentonite in accordance with different types of hardened concrete. (C) 2008 Elsevier Ltd. All rights reserved.
  • KABE KEITARO, SUGIYAMA TAKAFUMI, NAKARAI KEN'ICHIRO, TSUJI YUKIKAZU
    材料 The Society of Materials Science, Japan 57 (10) 1005 - 1010 0514-5163 2008 [Not refereed][Not invited]
     
    In present paper the applicability of resistivity of concrete for evaluating chloride penetration is discussed. The resistivity of concrete was measured using an AC power source with 15 voltages and 950Hz. Effective diffusion coefficient of chloride ions in concrete was also determined by chloride migration test that is specified by JSCE G571-2003. Normal concrete with varied W/Cs, fly ash concrete and concrete with high strength lightweight aggregate made of fly ash were studied. Theoretical formula was applied to estimate apparent diffusion coefficient of chloride ions using measured resistivity values. In this calculation the transference number of chloride ions in concrete was determined empirically based on the resistivity tests and the migration tests.
  • PROMENTILLA Michael Angelo B, SUGIYAMA Takafumi, HITOMI Takashi, TAKEDA Nobufumi
    日本コンクリート工学協会論文集 JCI-C73 357 - 366 2007/12/21 [Not refereed][Not invited]
  • Yasunori Matsuda, Takafumi Sugiyama, Naoki Tougezaka, Yukikazu Tsuji
    Zairyo/Journal of the Society of Materials Science, Japan 56 (8) 742 - 747 0514-5163 2007/08 [Refereed][Not invited]
     
    In order to improve the durability of concrete structures under harsh chloride-laden environments the use of surface coating and cross sectional restoration methods has been increased. For these methods polymer cement mortar becomes of a primary repair material. Then interface phenomena between the polymer cement mortar and concrete as the substrate needs to be clarified with regard to chloride penetration. In this paper the results of electrical resistance tests and chloride migration tests have been provided. Interface resistance of repaired concretes has been studied by comparing electrical resistance obtained experimentally and by calculations using the ohm's law on a series circuit. It is found that the interface resistance is controlled by the type of polymer cement mortars, mix proportions of concrete and the ages. Increased interface resistance is verified by decreased flux in the chloride migration tests. For repaired concrete by cross sectional restoration, the interface resistance may be ignored where the resistance obtained by the experiment and calculation was equal. © 2007 The Society of Materials Science.
  • 峠坂直樹, 杉山隆文, 松田康紀, 半井健一郎
    コンクリート工学年次論文集 日本コンクリート工学協会 29 (1) 975 - 980 1347-7560 2007/07/30 [Not refereed][Not invited]
     
    断面修復材や表面被覆材として使用されるポリマーセメントモルタルで表面保護したコンクリートの塩分浸透性を把握することを目的に,電気泳動試験により表面保護コンクリートの実効拡散係数を求め,等価かぶりに基づいた塩化物イオンの浸透予測を行った。表面保護コンクリートの実効拡散係数は,ポリマーセメントモルタルおよびコンクリートの実効拡散係数とその厚さによって異なり,基盤となるコンクリートにフライアッシュコンクリートを用いることで,塩化物イオン浸透に対する抵抗性は著しく増大することが示された。
  • Shigeru Takahashi, Etsuo Sakai, Takafumi Sugiyama
    JOURNAL OF ADVANCED CONCRETE TECHNOLOGY 5 (2) 201 - 207 1346-8014 2007/06 [Not refereed][Not invited]
     
    Tank leaching tests were carried out to investigate the behavior of leaching trace elements from monolith samples. This study consists of two series. and the trace element used was hexavalent chromium. In Series I, the influence of the leachant/surface area of the specimen (L/S ratio) on the leaching amount was investigated. The leaching amount was found to increase with the amount of worked water. This shows that any L/S ratio can be selected in the tank leaching test. In Series II, the influence of the curing conditions of concrete on the leaching amount was investigated. In the case of concrete cured under sealed conditions, hexavalent chromium hardly leached. On the other hand, in the case of concrete dried in the room, the amount of leaching of hexavalent chromium became large. Carbonation was found to cause the decomposition of cement hydrates and the release of fixed hexavalent chromium. The leaching of hexavalent chromium from using concrete was evaluated from these results. When water works continuously against concrete, the leaching of hexavalent chromium hardly affects the environment for water. When rainwater flows on the drying surface of concrete, the amount of leaching at the first rainfall was comparatively large, but deceased with subsequent rainfall.
  • TOMIZAWA NAOMI, SUGIYAMA TAKAFUMI, TSUJI YUKIKAZU
    セメント・コンクリート論文集 (60) 162 - 168 0916-3182 2007/02/20 [Not refereed][Not invited]
  • HORI AKIHIRO, TSUJI YUKIKAZU, SUGIYAMA TAKAFUMI
    セメント・コンクリート論文集 (60) 220 - 226 0916-3182 2007/02/20 [Not refereed][Not invited]
  • Michael Angelo B. Promentilla, Takafumi Sugiyama
    PROCEEDINGS OF THE FIRST INTERNATIONAL CONFERENCE ON RECENT ADVANCES IN CONCRETE TECHNOLOGY 101 - 112 2007 [Refereed][Not invited]
     
    Quantification of tortuosity plays an important role in the understanding and modeling of microscale transport processes in cement-based materials. In this regard, this paper presents a method to characterize the three-dimensional (3D) pore structure and estimate the tortuosity in a nondestructive way with the use of X-ray synchrotron radiation microtomography. We use adaptive thresholding and cluster labeling technique to extract the percolating pore space from the 3D image set. We then compute the diffusion tortuosity based on random walk simulation in the extracted digitized pore space. We demonstrate the capability of the proposed method as being applied in the investigation of the 3D micro-geometry and tortuosity of fly ash concrete and deteriorated mortar.
  • SUGIYAMA TAKAFUMI, ISHII TOSHIAKI, MACHIDA YOSHITSUGU, TSUJI YUKIKAZU
    土木学会論文集 E Japan Society of Civil Engineers 62 (3) 531 - 541 1880-6066 2006/10/25 [Not refereed][Not invited]
     
    Present paper shows effects that bar arrangement in concrete have on gas permeability through crack. Experimental set-up enables simultaneous gas flow through crack during which concrete cylinder with bar arrangement is loaded by the split tensile strength test configuration. Crack openings were measured at both ends of the concrete cylinder and gas pressure difference and volumetric gas flow rate were monitored. It was found that gas permeability was different despite an equal crack opening and was depended on the bar arrangement. Steel ratio and the projected surface area of steel that was in the way for the flow of gas in the crack were used to explain the effect of the bar arrangement
  • 杉山隆文, 高橋茂
    土木学会論文集 E Japan Society of Civil Engineers 62 (3) 587 - 591 1880-6066 2006/10/25 [Not refereed][Not invited]
  • 有賀大峰, 辻幸和, 池田正志, 杉山隆文
    コンクリート工学年次論文集 日本コンクリート工学協会 28 (2) 715 - 720 1347-7560 2006/07/30 [Not refereed][Not invited]
     
    土木学会コンクリート標準示方書に規定されているRC梁の曲げひび割れ幅の算定式より求まる値は,載荷試験より得られる実測値と比較すると差異があるとの報告を既に行ってきた。そこで本研究では,同一の断面形状寸法および配筋で,せん断スパン比のみが異なる供試体について曲げ載荷試験を行い,既往の算定式の適合性を評価した。その結果,せん断スパン比を変化させることにより,曲げひび割れ幅の実測値の算定値に対する分布には明確な相違が認められた。
  • 杉山隆文
    セメント・コンクリート セメント協会 (713) 27 - 32 0371-0718 2006/07/10 [Not refereed][Not invited]
  • 杉山隆文, 河合研至
    セメント・コンクリート セメント協会 (706) 11 - 20 0371-0718 2005/12/10 [Not refereed][Not invited]
  • Takafumi Sugiyama, Kosei Fukuoka, Yukikazu Tsuji
    Zairyo/Journal of the Society of Materials Science, Japan 54 (8) 816 - 821 0514-5163 2005/08 [Refereed][Not invited]
     
    Long term behavior of a bentonite sand mixture used for the disposal of radioactive wastes has been of great concern when it continuously contacts with concrete. This is explained by the fact that the characteristics of the bentonite will be altered due to the leaching of calcium ions in the concrete. In particular the Sodium type (Na type) bentonite exhibits a reduced expansion characteristic. However little research has been conducted using a bentonite-concrete composite system to investigate long term effects. In this present research an alteration of the characteristics of the Na type bentonite is studied by the use of a concrete bentonite composite specimen. An electrical migration method was employed to accelerate the transport of calcium ions present in the pore solution in concrete through the interface of a bentonite sand mixture. A constant DC voltage of 15 V was continuously applied to a concrete bentonite composite specimen for 50 days. Chemical analysis for cation content and expansion force, the measurements of EPMA and XRD were conducted.
  • 坂本淳, 新藤竹文, 丸屋剛, 杉山隆文
    コンクリート工学年次論文集 日本コンクリート工学協会 27 (1) 325 - 330 1347-7560 2005/06/25 [Not refereed][Not invited]
     
    本論文は,超高強度繊維補強コンクリート等の高緻密なコンクリートの実効拡散係数を電気泳動法により測定した結果と乾湿繰返しかつ塩水噴霧条件下における促進腐食試験結果を報告するものである。試験の結果から,超高強度繊維補強コンクリートの実効拡散係数は水セメント比35%の高強度コンクリートに対して1/100以下であり,2年近く経過した促進腐食試験においても塩化物イオンの浸透はみられず,同コンクリートの遮塩性能が極めて高いこと等が明らかとなった。
  • Kenji Kawai, Takafumi Sugiyama, Koichi Kobayashi, Susumu Sano
    Journal of Advanced Concrete Technology 3 (3) 435 - 456 1346-8014 2005 [Refereed][Not invited]
     
    This paper aims to provide common basis for the estimation of emission inventory data necessary for the evaluation of environmental impact of a concrete structure through its life cycle. Intensive literature survey and hearing to the institutes concerned have been deliberately conducted to collect relevant data to concrete materials, other materials involved, construction, demolition, and disposal and recycling. Consequently emission inventory data of CO2, SOX, NOX, and particulate matter were able to be prepared in an objective way. In addition, fundamental inventory data of these emission gases and particulate matter were provided for various kinds of energy. Furthermore most commonly used machines, instruments and other equipments on concrete structure construction are presented and provided for their related inventory data. In this way, inventory data regarding 91 detail items in total were able to be provided. By using these inventory data, four case studies where environmental impact caused by the construction of concrete structures was considered as a performance parameter of the structures similarly to serviceability, safety, and durability of the structures were also investigated based on design methods proposed previously by the authors in order to confirm the applicability of these inventory data to environmental performance evaluation of concrete structures. Copyright © 2005 Japan Concrete Institute.
  • SUGIYAMA TAKAFUMI, SHIMIZU SHUNGO, RITTHICHAUY W, TSUJI YUKIKAZU
    土木学会論文集 公益社団法人 土木学会 2004 (767) 227 - 238 0289-7806 2004/08/20 [Not refereed][Not invited]
     
    Pore structure characteristic of a hardened mortar is quantified as a pore structure coefficient (PSC) that is defined and calculated in this research using an effective diffusion coefficient obtained from a migration test. PSC is composed of porosity and tortuosity. PSC was found to be controlled partially by the amount of pores ranged from 100nm to 2μm in the diameter. Potassium ion as a tracer ion in the migration test provided reasonably consistent PSC as well as chloride ion.
    Larger tortuosity of fly ash mortar resulted in lower PSC despite larger porosity. The PSC for fly ash mortar appeared to account for part of micro pores that may reduce ionic diffusion. An electrical effect of the micro pores would seem to restrict the movement of diffusing ions.
  • TAKEWAKA KOJI, SUGIYAMA TAKAFUMI
    土木学会論文集 公益社団法人 土木学会 (767) 1 - 9 0289-7806 2004/08/20 [Not refereed][Not invited]
  • 杉山隆文, 高見満, RITTHICHAUY, 辻幸和
    コンクリート工学年次論文集 日本コンクリート工学協会 26 (1) 819 - 824 1347-7560 2004/06/25 [Not refereed][Not invited]
     
    水セメント比が一定で,単位水量が異なるコンクリートの塩化物イオン浸透性を調べた。電気泳動法より求めた塩化物イオンの実効拡散係数は,単位水量を153～202kg/m^3の範囲で増加させると,増加する傾向が認められた。この傾向は,水セメント比が65%と大きい場合に顕著であった。鉄筋の腐食時期をFick式を用いて模擬計算した結果,単位水量の影響を受けるが,水セメント比の影響がより顕著であることを示した。また,単位水量が増加すると材料分離が生じ易くなることを確認し,その結果,材料分離が生じた表層部(約20mm)の全塩化物イオン濃度が増加することを,422日間の長期塩水浸せき試験から明らかにした。
  • Takafumi Sugiyama, Yukikazu Tsuji
    Zairyo/Journal of the Society of Materials Science, Japan 52 (2) 198 - 203 0514-5163 2003 [Not refereed][Not invited]
     
    Chloride ingress into concrete with high strength lightweight aggregate made of fly ash (HFA aggregate) as the coarse aggregate was evaluated by a steady state migration test and chloride ponding test. It was found that the migration coefficient obtained from the migration test could represent appropriate ranking on chloride ingress into the concrete with different W/Cs. The effect of HFA aggregate on the chloride ingress was negligible and a similar migration coefficient to that of normal weight aggregate was given. In addition, an observation using EPMA showed no chloride ion present in the HFA aggregate itself after the migration test. Chloride ponding test also exhibited same ranking providing increased apparent chloride diffusion coefficients with increased W/C. Migration coefficients might be related quantitatively to the apparent diffusion coefficient with chloride binding isotherm being properly considered.
  • Takafumi Sugiyama, Masaki Minatoya, Yukikazu Tsuji
    Zairyo/Journal of the Society of Materials Science, Japan 52 (9) 1049 - 1054 0514-5163 2003 [Refereed][Not invited]
     
    A gas pressure difference of 0.2N/mm2 was maintained between the cross sections of concrete with simultaneous increase of loading in the split tensile strength test configuration. A single crack that formed in the longitudinal direction parallel to the loading increased the gas permeability of the concrete. It was found that gas permeability was gradually increased at a crack opening of about 0.02mm and then rapidly increased until the crack opening reached 0.08mm. The degree of water saturation of concrete had significant effect on the formation of the crack and hence failure of the concrete under investigation. Oven dried concrete exhibited gradual increase of the gas permeability while water saturated concrete showed rapid increase of the gas permeability at the crack opening of 0.02mm. In this way the gas permeability of concrete subjected to the split tensile strength test was controlled by the failure mechanism.
  • Sugiyama Takafumi, Ritthichauy Worapatt, Tsuji Yukikazu
    ACT Japan Concrete Institute 1 (2) 127 - 138 1346-8014 2003 
    This paper presents a new method for numerically calculating the concentration profiles of both solid calcium and total chloride ions (Cl−) in concrete in contact with 3% (0.5 mol/l) sodium chloride (NaCl) solution. Since the diffusion of ions present in the pore solution is a primary controlling factor, the application of mutual diffusion coefficients of corresponding ions that are influenced by the concentration of other coexisting ions is proposed. The method of calculation is based on the generalized form of Fick's First Law suggested by Onsager, which is composed of the Onsager phenomenological coefficient and the thermodynamic force between ions, which occurs according to the gradient of electrochemical potential in a multicomponent concentrated solution for the pore solution. In addition, the chemical equilibrium for Ca(OH)2 dissolution and C-S-H decalcification are also modeled and coupled with diffusion. Increased porosity due to dissolved Ca2+ and a chloride binding isotherm are taken into consideration. The concentration profiles of solid calcium and the presence of Friedel's salt in mortar specimens are experimentally identified by the X-ray diffraction method (XRD) and the thermal analysis (TG/DTA) as well as the total chloride profile using an acid extraction method after three years of exposure to 0.5 mol/l NaCl solution. This experimental result verifies the calculation result.
  • SORN V, YAMADA YOSHITOMO, SUGIYAMA TAKAFUMI, OSHIRO TAKESHI
    日本建築学会構造系論文集 日本建築学会 67 (560) 17 - 25 1340-4202 2002/10/30 [Not refereed][Not invited]
     
    This paper presents the study on penetrating characteristics of chloride ions into fly ash concrete, where fly ash has been used as the replacement of fine aggregates. Several tests such as rapid chloride permeability test, drying-wetting acceleration test and exposure test under marine environment have been performed. From these tests, the diffusion coefficients have been obtained and these are evaluated to clear the chloride resistivity of fly ash concrete. The results show that the contents of fly ash in concrete are greatly related to the chloride resistivity.
  • SUGIYAMA TAKAFUMI, VIRA S, TSUJI YUKIKAZU, OSHIRO TAKESHI
    土木学会論文集 土木学会 711 (711) 191 - 203 0289-7806 2002/08/20 [Not refereed][Not invited]
  • SORN V, 山田義智, 杉山隆文, 大城武
    コンクリート工学年次論文集 日本コンクリート工学協会 24 (1) 603 - 608 1347-7560 2002/06/08 [Not refereed][Not invited]
     
    本研究は,フライアッシュを細骨材の一部代替として使用するコンクリートについて,塩化物イオンの浸透性状を把握することを目的としている。ここでは,水セメント比とフライアッシュ混和量をパラメータとした試験体について,電気泳動試験および乾湿繰り返し促進試験を行い,塩化物イオンの浸透性状を把握している。これらの試験結果より見掛けの拡散係数を求め,塩化物イオンの浸透性状を評価している。
  • TSUJI YUKIKAZU, SUGIYAMA TAKAFUMI, YAMAGUCHI MITSUTOSHI
    土木学会論文集 公益社団法人 土木学会 2002 (697) 179 - 192 0289-7806 2002/02/20 [Not refereed][Not invited]
     
    The strengthening effect using steel plate on the structural performance of reinforced concrete beam with vertical construction joint was studied. Vertical joint was located within the shear span of the beam and steel plate was used to cover the joint so that the beam could perform structurally as normal beam without construction joint. The tensile strain of the stirrup increased noticeably at the position near the vertical joint. However, the steel plate could reduce local increase in the strain of the stirrup. In addition, it was found that the steel plate contributed to resist the part of the shear force on the beam with the stirrup resulting in the prevention from the stirrup failure.
  • SUGIYAMA TAKAFUMI, OHATA MASATSUGU, IGARASHI TOMOMI, TSUJI YUKIKAZU
    セメント・コンクリート論文集 56 (56) 216 - 223 0916-3182 2002 [Not refereed][Not invited]
  • 湊谷昌樹, 杉山隆文, 辻幸和, GUPTA S
    コンクリート工学年次論文集 23 (2) 829 - 834 1347-7560 2001/06/08 [Not refereed][Not invited]
  • 大畑公嗣, 杉山隆文, 辻幸和, GUPTA S
    コンクリート工学年次論文集 23 (2) 511 - 516 1347-7560 2001/06/08 [Not refereed][Not invited]
  • 小川彰一, 吉岡民夫, 杉山隆文
    コンクリート工学年次論文集 23 (1) 385 - 390 1347-7560 2001/06/08 [Not refereed][Not invited]
  • 中田学, 辻幸和, 杉山隆文, 佐藤元
    コンクリート工学年次論文集 23 (1) 445 - 450 1347-7560 2001/06/08 [Not refereed][Not invited]
  • SUHARA KENTARO, HASHIMOTO CHIKANORI, TSUJI YUKIKAZU, SUGIYAMA TAKAFUMI
    土木学会論文集 公益社団法人 土木学会 676 (676) 105 - 115 0289-7806 2001/05/20 [Not refereed][Not invited]
     
    This paper has been conducted to develop a novel system for pumping concrete with a minimizing degree of the pulsation in the pipe. A pumping devise designed on a small scale has two hydraulic cylinders: one for a main stream and the other for a supplemental stream, respectively. A visualization technique was employed to determine satisfactory levels of the pulsation of the supplemental stream that resulted in minimizing the pulsatile flow of concrete flowing through the main pipe after being combined with the supplemental stream.
    This research concludes that pumping concrete could be operated most smoothly and without causing an adverse pulsation through the pipe by arranging the pulsation levels of the supplemental stream with the main flow of a certain level of the pulsation when the angle of confluent is 45-dgree. Also, it was found that there existed was the segregation of model concrete in confluent during pulsatile flow and that the volumetric ratio of coarse aggregate to mortar influenced the segregation of concrete.
  • OGAWA SHOICHI, YOSHIOKA TAMIO, SUGIYAMA TAKAFUMI
    セメント・コンクリート論文集 (55) 587 - 592 0916-3182 2001 [Not refereed][Not invited]
  • 清水俊吾, 杉山隆文, 辻幸和, GUPTA S
    コンクリート工学年次論文集 22 (1) 115 - 120 1347-7560 2000/06/01 [Not refereed][Not invited]
  • VIRA S, 大城武, 松藤泰典, 杉山隆文
    コンクリート工学年次論文集 22 (1) 139 - 144 1347-7560 2000/06/01 [Not refereed][Not invited]
  • Yukikazu Tsuji, Takafumi Sugiyama, Chikanori Hashimoto
    Zairyo/Journal of the Society of Materials Science, Japan 49 (10) 1127 - 1132 0514-5163 2000 [Not refereed][Not invited]
     
    Self-compacting concrete has an unique characteristic which may influence on the flexural and/or shear strength of a reinforced concrete beam with vertical construction joint. In this research vertical construction joint was intended to be present either in the mid-span of the beam or in the middle of the shear span. Crack initiation loads, the crack width, failure loads and failure modes were investigated. With the vertical construction joint present in the mid-span the crack initiation load was reduced to 60% of that of a control beam without joint. In addition, increased loads resulted in the substantial increase of the crack width. On the other hand, flexural crack formed at the construction joint in the middle of the shear span with lower loads leading to the shear failure with about 75% of the ultimate load of a control beam with an equal steel ratio.
  • 杉山隆文, 井川一弘, 山本隆信
    日本コンクリート工学協会論文集 (53) 221 - 226 1999/11 [Not refereed][Not invited]
  • MURATA YOKO, SUGIYAMA TAKAFUMI, TSUJI YUKIKAZU
    コンクリート工学年次論文報告集 日本コンクリート工学協会 21 (2) 1081 - 1086 1340-4741 1999/06/21 [Not refereed][Not invited]
     
    凍結融解作用を繰り返したフライアッシュコンクリートに対して,電気的手法を用いた塩分浸透試験を行った。フライアッシュの置換率(セメントの内割り)が増加すると,水申養生期間が28日間の場合で,塩分浸透性は大きくなった。しかし,水中養生期間を91日間確保して圧縮強度を増加させると,凍結融解作用のサイクル数に関わらず,各フライアッシュコンクリートの塩分浸透性は同程度であった。
  • YAMAGUCHI MITSUTOSHI, TSUJI YUKIKAZU, SUGIYAMA TAKAFUMI, IKEDA MASASHI
    コンクリート工学年次論文報告集 日本コンクリート工学協会 21 (3) 469 - 474 1340-4741 1999/06/21 [Not refereed][Not invited]
     
    鉛直打継目を有する断面形状寸法が異なるRCはりを作製し,そのせん断性状をスターラップのひずみの増加割合に着目し,実験的に検討した。その結果,鉛直打継目を有するRCはりのスターラップのひずみは,鉛直打継目を有さない一体型のRCはりのものと異なり,斜めひび割れの発達状況に大きな影響を受け,大きな局所的なひずみ増加を示した。また,鉛直打継目を有するRCはりにプレストレスを与えることで,スターラップのひずみの局所的な増加を抑え,一体型のRCはりと同等のせん断性状を示すことが明らかとなった。
  • URANO SHINJI, HASHIMOTO CHIKANORI, TSUJI YUKIKAZU, SUGIYAMA TAKAFUMI
    土木学会論文集 土木学会 599 (599) 131 - 141 0289-7806 1998/08 [Not refereed][Not invited]
  • HORIUCHI ZEN, SUGIYAMA TAKAFUMI, TSUJI YUKIKAZU, HASHIMOTO CHIKANORI
    コンクリート工学年次論文報告集 日本コンクリート工学協会 20 (1) 203 - 208 1340-4741 1998/06 [Not refereed][Not invited]
     
    コンクリートの電気伝導度から,多孔質体の細孔構造の物理的な指標である屈曲度およびfGr通at沁鷺factorを算定した。フライアッシュコンクリートでは,これらの物理特性値が大きく,そのことは塩化物イオンの拡散を抑制することと関連することを明らかにした.
  • OTA TOMONORI, YOKOTA TAKAO, TSUJI YUKIKAZU, SUGIYAMA TAKAFUMI
    コンクリート工学年次論文報告集 日本コンクリート工学協会 20 (1) 479 - 484 1340-4741 1998/06 [Not refereed][Not invited]
     
    せん断スパン中央に鉛直打継目を設けた高強度および普通強度のRCはりを作製し,そのせん断耐力の低下等を実験的に検討した。その後,打継目を幅,厚さの異なる鋼板により被覆補強を施した場合のせん断性状を検討した。その結果,鉛直打継目を鋼板で被覆することにより,鉛直打継目が存在しないRCはりと同等の耐力を得ることができ,せん断圧縮破壊した普通強度のRCはりは,曲げ引張破壊へと移行した。そして,鋼板による補強機構にも考察を加えた。
  • YAMAMOTO TAKANOBU, SUGIYAMA TAKAFUMI, TSUJI YUKIKAZU
    コンクリート工学年次論文報告集 日本コンクリート工学協会 20 (2) 97 - 102 1340-4741 1998/06 [Not refereed][Not invited]
     
    本研究の目的は,フライアッシュ用の空気量調整剤をAE減水剤と併用した場合の,フライアッシュコンクリートにおける空気連行性およびブリーディング量を検討することである。実験では,空気量調整剤の種類および添加率を変化させて,各フレッシュ時の性状を考察した。また,品質の異なる2種類のフライアッシュを用いて,最大45%までセメントの一部と置換した場合について考察した。各配合における旭減水剤の添加率を一定とした本実験の範囲内では,目標値である5%の空気量を得るために必要な空気量調整剤の添加率は,フライアッシュの品質に関わらず,30%までの置換率の増加に対して比例的に増加した。
  • KOYAMA HIROMITSU, HASHIMOTO CHIKANORI, TSUJI YUKIKAZU, SUGIYAMA TAKAFUMI
    コンクリート工学年次論文報告集 日本コンクリート工学協会 20 (2) 295 - 300 1340-4741 1998/06 [Not refereed][Not invited]
     
    任意の型枠内でのフレッシュコンクリートの変形特性を定量的に評価することを目的として,可視化実験手法を用いて流動状況を観察し,変形挙動をひずみ速度の時間経過に伴う発生状況の違いにより定量化を行った。実験の結果,モデルコンクリートはスラブ型枠および壁型枠内の流動において,モルタルの粘性に関わらずそれぞれ一定のレベルのひずみ速度を有していること,壁型枠内の流動はスラブ型枠内の流動に比べひずみ速度が2倍程度であるとともに,主ひずみ速度と流動方向とのなす角度が大きくなることが明らかになった。
  • URANO SHINJI, HASHIMOTO CHIKANORI, TSUJI YUKIKAZU, SUGIYAMA TAKAFUMI
    土木学会論文集 土木学会 585 (585) 163 - 174 0289-7806 1998/02 [Not refereed][Not invited]
  • HASHIMOTO CHIKANORI, TSUJI YUKIKAZU, SUGIYAMA TAKAFUMI
    セメント・コンクリート論文集 (51) 582 - 587 0916-3182 1997/12 [Not refereed][Not invited]
  • TSUJI YUKIKAZU, SUGIYAMA TAKAFUMI, HASHIMOTO CHIKANORI, MATSUNAMI YASUYUKI
    土木学会論文集 土木学会 571 (571) 169 - 183 0289-7806 1997/08 [Not refereed][Not invited]
  • IGARASHI KAZUMA, HASHIMOTO CHIKANORI, TSUJI YUKIKAZU, SUGIYAMA TAKAFUMI
    コンクリート工学年次論文報告集 日本コンクリート工学協会 19 (1) 427 - 432 1340-4741 1997/06 [Not refereed][Not invited]
     
    ポンプ圧送時に発生する管内脈動流を小型ポンプ圧送装置で再現し、フレッシュコンクリートの可視化実験手法を適用し、脈動流の流速変動と圧力変動の定量化を行った。その実験結果を1次元の振動モデルを用いて解析した結果と比較し、振動モデルにおける体積弾性率と粘性係数を求め、脈動流に対するこれらの数値の物理的意味にっいて考察した。その結果、脈動時の管内流動は、体積弾性率に関してほぼ一定であるが、粘性係数は変化することから同じ管内圧力でも管内流速が異なる可能性があることが明らかとなった。
  • IKEDA MASASHI, TSUJI YUKIKAZU, HASHIMOTO CHIKANORI, SUGIYAMA TAKAFUMI
    コンクリート工学年次論文報告集 日本コンクリート工学協会 19 (2) 1647 - 1652 1340-4741 1997/06 [Not refereed][Not invited]
     
    鉄筋コンクリートはりと鋼板にポリマーセメントモルタルを塗布して3日後に、両者の間に充てんモルタルを充てんして接着させたはり供試体の曲げ強度試験を行い、はりの曲げ・せん断性状および接着面における水平せん断性状の実験結果を報告した。実験要因としては、充てんモルタルの厚さ、せん断スパン内における接着面積の大きさ、鋼板の厚さを採ったが、鋼板のはく離を評価するためには、鋼板の受け持つ引張力をせん断スパン内の鋼板の接着面積で除した値で表される水平せん断応力度を提案した。この水平せん断応力度が0.5～1.3N/mm2に達すると、接着していた鋼板のはく離が生じた。
  • NAGAOKA SATORU, SUGIYAMA TAKAFUMI, TSUJI YUKIKAZU, HASHIMOTO CHIKANORI
    コンクリート工学年次論文報告集 日本コンクリート工学協会 19 (1) 571 - 576 1340-4741 1997/06 [Not refereed][Not invited]
     
    塩化物イオンの電気的泳動を利用した促進試験方法を用いて、塩化物イオンの移動が定常状態および非定常状態にある場合から、それぞれ有効拡散係数および見掛けの拡散係数を定義して、セメントペーストおよびコンクリートについて各拡散係数を比較した。定常状態から得られた有効拡散係数は、非定常状態から得られた見掛けの拡散係数よりも大きい結果となった。
  • SUHARA KENTARO, HASHIMOTO CHIKANORI, TSUJI YUKIKAZU, SUGIYAMA TAKAFUMI
    コンクリート工学年次論文報告集 日本コンクリート工学協会 19 (1) 421 - 426 1340-4741 1997/06 [Not refereed][Not invited]
     
    ピストン式コンクリートポンプによるフレッシュコンクリートの圧送において,圧送時の管路内流速および管路内圧力は,ピストンの往復に同期して変動する,このため,圧送管路内の流れは脈動流となる.この脈動の平滑化には,脈動の変動部分に対して逆位相を有する脈動を外部より加え合わせることで可能となる.異なる2つの脈動流の合流部を可視化し,流速分布を計測することで,合流部の流動を横流入のある1次元流れとしてのモデル化を行った.その結果,このモデルは合流部の流動をマクロ的に捉えるのに有効であることが明らかとなった.
  • YOKOTA TAKAO, HASHIMOTO CHIKANORI, TSUJI YUKIKAZU, SUGIYAMA TAKAFUMI
    コンクリート工学年次論文報告集 日本コンクリート工学協会 19 (2) 681 - 686 1340-4741 1997/06 [Not refereed][Not invited]
     
    同一条件における多数のはり供試体の曲げ載荷試験を行い、曲げひび割れ幅に着目し統計的評価を行った。ひび割れ本数の変動は全変形量の変動には影響を及ぼさないが、一本当たりのひび割れ幅については多少の変動を伴う。しかし、引張鉄筋位置での曲げひび割れ幅は、土木学会コンクリート標準示方書に規定されている曲げひび割れ幅算定式から求まる値より、いずれも小さかった。また引張縁における曲げひび割れ幅を求める際には、上述の曲げひび割れ幅算定式に鉄筋のかぶりを考慮した補正係数を乗じることにより、より正確な値を得ることができた。
  • SUGIYAMA TAKAFUMI
    コンクリート工学 日本コンクリ-ト工学協会 35 (5) 29 - 32 0387-1061 1997/05 [Not refereed][Not invited]
  • セメント・コンクリート論文集 51 678 - 683 1997 [Not refereed][Not invited]
  • SUGIYAMA Takafumi, HASHIMOTO Tomoaki, Tsuji Yukikazu, HASHIMOTO Chikanori
    コンクリート工学年次論文報告集 日本コンクリート工学協会 19 (1) 859 - 864 1340-4741 1997 [Not refereed][Not invited]
     
    直流定電圧を用いて塩化物イオンを電気的にコンクリート中を移動させる促進試験の有効性について、普通コンクリート(W/C=55%)および粉体系の高流動コンクリート(W/C=30%)を試験体として調べた。実験結果から促進試験で求めた拡散係数(D)と養生期間(t)をD=atbの関係で表した。また、高流動コンクリートの拡散係数は普通コンクリートの25～30%と小さく、595日間の実験室内の暴露試験から得られた塩分浸透性状を良く反映していた。
  • SUGIYAMA Takafumi, TSUJI Yukikazu, HASHIMOTO Chikanori, KUROIWA Toshiyuki
    土木学会論文集 土木学会 557 (557) 101 - 109 0289-7806 1997 [Not refereed][Not invited]
  • T Sugiyama, TW Bremner, TA Holm
    ACI MATERIALS JOURNAL 93 (5) 443 - 450 0889-325X 1996/09 [Not refereed][Not invited]
     
    The effect of compressive stress on the permeability of concrete was experimentally investigated using nitrogen gas as the flowing substance. A uniaxial compressive load was applied to a cylindrical hollow concrete specimen and increased by steps until failure, while a constant nitrogen gas pressure was maintained between the walls of the hollow cylinder and the volumetric gas flow rate was measured in a steady state. Gas permeability was then calculated and compared at increasing stress levels. Structural lightweight concrete with water-cement ratios of 0.4 and 0.6 was compared with normal-weight concrete with equal water-cement ratios and at similar stress levels. The stress level at which gas permeability increased significantly (significant stress level) was 76 to 79 percent of the ultimate strength for normal-weight concrete, whereas 82 to 89 percent of ultimate strength for the lightweight concrete. Structural lightweight concrete had both a higher significant stress level and a higher stress level at which dilation due to microcracking was noted (critical stress level) compared to normal-weight concrete. Furthermore, normal-weight and structural lightweight concrete with different degrees of water saturation were tested. A higher degree of saturation resulted in a higher significant stress level.
  • KAKO MAKOTO, HASHIMOTO CHIKANORI, SUGIYAMA TAKAFUMI, TSUJI YUKIKAZU
    コンクリート工学年次論文報告集 日本コンクリート工学協会 18 (1) 465 - 470 1996/06 [Not refereed][Not invited]
     
    本研究は、高流動コンクリートのコンシステンシー試験として用いられているスランプフロー試験、Lフロー試験およびV漏斗試験装置内を流動するフレッシュ頴ンクリートの変形特性を定量化するために、フレッシュコンクリートの可視化モデルを用いて、ひずみ嶽ゼット法に基づいた最大せん断ひずみ速度分布を求めた。その結果、スランプフロー試験とLフロー試験では、試験開始直後約1秒間以内では10～20/sec程度のひずみ速度が、開始直後1秒以降では0.5/sec以下のひずみ速度が発生する.一方、V漏斗試験では、常に10/sec程度のひずみ速度が発生することが明らかになった。
  • T Sugiyama, TW Bremner, Y Tsuji
    CEMENT AND CONCRETE RESEARCH 26 (5) 781 - 790 0008-8846 1996/05 [Not refereed][Not invited]
     
    Chloride diffusion coefficient and gas permeability of concrete were experimentally determined. The relationship between them is discussed. Chloride diffusion coefficient was determined using saturated concrete by an accelerated electrical testing method. The chloride diffusion coefficient was found to be controlled by the water-to-cement ratio with about 2.2 times higher chloride diffusion coefficient for concrete with the water-to-cement ratio of 0.6 as compared with that of 0.4 water-to-cement ratio. Gas permeability was greatly influenced by the degree of saturation of the concrete. A correlation was found between chloride diffusion coefficient and gas permeability. Lightweight aggregate concrete was tested and compared with normal weight concrete with respect to chloride diffusion and gas permeability.
  • SUGIYAMA TAKAFUMI, NAGAOKA SATORU, HASHIMOTO CHIKANORI, TSUJI YUKIKAZU
    日本コンクリート工学協会論文集 (39) 53 - 58 1996/05 [Not refereed][Not invited]
  • SUGIYAMA Takafumi, NAGAOKA Satoru, TSUJI Yukikazu, HASHIMOTO Chikanori
    コンクリート工学年次論文報告集 日本コンクリート工学協会 18 (1) 981 - 986 1996 [Not refereed][Not invited]
     
    塩化物イオンによる鋼材腐食に対して、合理的な耐久設計あるいは劣化予測を行う揚合に重要となる、コンクリートの塩化物イオン拡散係数を、電気的泳動を利用した促進試験方法によって求めた。本促進試験方法は、直流定電圧方式で15Vの電位差を厚さ5cmのコンクリートに印加して、塩化物イオンを見掛け上厚さ方向に、一次元的に電気的泳動させる。そして、塩化物イオンの移動が定常状態にある時のフラックスから、コンクリートの塩化物イオン拡散係数を算定した。その時に要する試験期間は2～3週間で、塩化物イオン拡散係数は、水セメント比の影響を大きく受けることが明らかになった。
  • MATSUNAMI YASUYUKI, NISHISU MINORU, SUGIYAMA TAKAFUMI, TSUJI YUKIKAZU
    コンクリート工学年次論文報告集 日本コンクリート工学協会 17 (2) 989 - 994 1340-4741 1995/06 [Not refereed][Not invited]
     
    異なる位置に鉛直打継目を設けて、補強材にFRPを用いたCPCはりの曲げおよびせん断性状を実験的に検討した。鉛直打継目をせん断スパン内に設けた場合は、等曲げモーメント区間に設けた場合より曲げひび割れ発生モーメントと斜めひび割れ発生モーメントが大きく、平均ひび割れ幅が小さくなった。また、鉛直打継目の位置に関わらず、膨張コンクリートの利用により曲げおよびせん断性状が向上した。鉛直打継目をせん断スパン内に設けたはりの破壊形式は、FRPの種類および格子間隔の大きさに関わらず、すべてせん断圧縮破壊となった。
  • ARAI NORIYUKI, HASHIMOTO CHIKANORI, SUGIYAMA TAKAFUMI, TSUJI YUKIKAZU
    コンクリート工学年次論文報告集 日本コンクリート工学協会 17 (1) 575 - 580 1340-4741 1995/06 [Not refereed][Not invited]
     
    本研究ではモデルアジテータを用いた可視化実験装置に画像処理装置を組み合わせ、モデルコンクリートを構成するモルタル相と粗骨材粒子の流速・流動方向を計測するシステムを用いて、かくはん時におけるモルタル相の粘性と粗骨材濃度がモルタル相と粗骨材の材料分離に及ぼす影響について検討した。その結果、アジテータのかくはん時に発生する材料分離は、モルタル相の粘性よりも粗骨材濃度による影響が大きいことが明らかになった。
  • SUGIYAMA TAKAFUMI
    コンクリート工学 33 (6) 44 - 51 0387-1061 1995/06 [Not refereed][Not invited]
  • IKEDA OSAMU, HASHIMOTO CHIKANORI, SUGIYAMA TAKAFUMI, TSUJI YUKIKAZU
    コンクリート工学年次論文報告集 日本コンクリート工学協会 17 (1) 557 - 562 1340-4741 1995/06 [Not refereed][Not invited]
     
    2軸強制練りミキサの可視化実験により得られたミキサ内のモデルコンクリートの流動機構が、実際のコンクリートの練混ぜ性能に及ぼす影響について検討することを目的とし、シリカフユーム混入コンクリートを用いた実機ミキサによる練混ぜ性能試験を行った。測定項目は、シリカフュームの分散率と圧縮強度、単位粗骨材量の変動係数とした。その結果、2軸強制練りミキサの練混ぜ性能は全体を循環させる流動を卓越させることで向上することが明らかになった。
  • HASHIMOTO CHIKANORI, SATO RYOICHI, SUGIYAMA TAKAFUMI, TSUJI YUKIKAZU
    コンクリート工学年次論文報告集 日本コンクリート工学協会 17 (1) 551 - 556 1340-4741 1995/06 [Not refereed][Not invited]
     
    ポンプ圧送において発生する脈動流は、圧送後のコンクリートの品質のみならず、圧送現場の環境やポンプ自体に対しても悪影響を及ぼす。本研究は、脈動流を抑制した新しいコンクリートポンプ機構の開発を目的とし、任意の波形の脈動流を設定することができる油圧シリンダー2本(主流と補流)を有する小型ポンプ圧送装置を試作し、主流で再現した脈動流に合流させて管内流動を平滑化させるために必要な補流の条件を、フレッシュコンクリートの可視化実験手法を用いて検討した。管内流速の経時変化から、脈動流の平滑化を実現させうる補流の条件が存在することが明らかになった。
  • ポンプ圧送時の管内脈動機構に関する実験的研究
    コンクリート工学年次論文報告集 Vol.17,No.1,pp.551-556 1995 [Not refereed][Not invited]
  • セメント・コンクリート論文集 No.49,pp.516-521 1995 [Not refereed][Not invited]
  • SUGIYAMA Takafumi, W. BREMNER Theodore, A. HOLM Thomas, TSUJI Yukikazu
    コンクリート工学年次論文報告集 日本コンクリート工学協会 17 (1) 985 - 990 1340-4741 1995 [Not refereed][Not invited]
     
    静的載荷を受ける中空円柱型のコンクリート供試体の内部表面に、透気方向が載荷方向に対して垂直になるように、窒素ガスを作用させ、応力レベル(破壊強度の百分率で表す)の増加に伴う透気係数の変化を調べた。コンクリートの透気係数は、応力レベルが76～79%に達すると著しく増大を開始し、別の実験で調べた、静的載荷による体積ひずみの変化がそれまでの減少から逆に増大に転じる臨界応力とよく一致した。
  • コンクリートの中の塩素イオンの透過に及ぼす荷重の影響
    6 (1) 239 - 248 1993 [Not refereed][Not invited]
  • SUGIYAMA TAKAFUMI, SAIKI NOBORU, FUJITA YOSHIO, ARIMA NOBUHIRO
    コンクリート工学年次論文報告集 日本コンクリート工学協会 12 (1) 191 - 196 1990/06 [Not refereed][Not invited]
  • SUGIYAMA Takafumi, SAEKI Noboru, FUJITA Yoshio, ARIMA Nobuhiro
    コンクリート工学年次論文報告集 日本コンクリート工学協会 12 (1) 191 - 196 1990 [Not refereed][Not invited]
  • SUGIYAMA Takafumi, SAEKI Noboru, FUJITA Yoshio
    コンクリート工学年次論文報告集 日本コンクリート工学協会 11 (1) 259 - 264 1989 [Not refereed][Not invited]

MISC

Books etc

Association Memberships

  • JAPAN PRESTRESSED CONCRETE INSTITUTE   THE SOCIETY OF MATERIALS SCIENCE, JAPAN   JAPAN CONCRETE INSTITUTE   JAPAN SOCIETY OF CIVIL ENGINEERS   

Works

  • Effective use of coal ash for Concrete
    1998 -2002
  • The Development of Life-Cycle-Simulation-Programe for concrete ander chloride-laden environment
    1999 -2001
  • Field Survey of Concrete Durability under Severe Environmental Conditions at Treat Island
    1991

Research Projects

  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
    Date (from‐to) : 2021/04 -2024/03 
    Author : 杉山 隆文, 松本 浩嗣, 高橋 駿人
     
    コンクリート構造物の建設需要が経済的、社会的、環境側面において多様化する中で、コンクリートに要求される性能が大きく変化している。品質を確保しながら生産性を高めることが共通しているが、その上で過酷環境、長寿命化、環境負荷低減などの条件を満足するコンクリートを実現することが求められている。そして、これらを満足する素材や配合設計の自由度が拡大する中、新しい素材や設計手法の開発において、性能を迅速に評価する手法の研究開発を目的としている。特に、耐凍害性の向上が期待される新素材である中空微小球の導入による気泡構造の可視化や研究期間が長期に及ぶ浸食作用による抵抗性評価のために、X線CT法に代表される放射線の優れた非破壊透視技術を活用した。 気泡構造はASTM法に代表されるリニアトラバース法が採用されるが、多くの労力を要していた。また、電子顕微鏡による断面観察によって中空微小球の分布の様子を観察していた。これら従来法は、いずれも平面観察であり空間分布を捉えることはできていなかった。そこで、X線CT法を用いることで、硬化体への特別な成型過程が不要で客観的な評価判定が可能となることを示した。さらに、直径3㎜で高さが5㎜の微小供試体を用いることで、マイクロメートルオーダーでの分析が可能なCT-XRD連成法を採用することで、コンクリートからのカルシウムイオンの溶出現象を可視化することが可能であることが推察された。 このように、放射線による非破壊透視技術によって、ブラックスボックスである構造体内部を立体的に画像として把握することができて、さらに繰り返し同一供試体の測定が可能であり、測定前の試料準備も不要になることから、評価判定までの生産性を著しく向上することが示された。
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
    Date (from‐to) : 2014/04 -2017/03 
    Author : SUGIYAMA TAKAFUMI, PROMENTILLA Michael
     
    This research has focused on X-ray CT as a nondestructive diagnostic method for concrete structures. Varied mechanisms of the alteration due to load application, water attack, carbonation, freezing and thawing action and the reinforcement corrosion were clarified. Deformed reinforcing bar embedded in concrete was clearly extracted. In addition, the amount of cross section reduction of electrically corroded rebar was calculated. A part of the cross section corroded in the early period and then spread over the entire cross section. The core was collected from the bottom surface of the road bridge RC slab, and as the crack length increased, chloride ions permeated deep. However, the influence of the crack width was not large. Furthermore, when carbonated and passed through water, the portlandite in the cracked concrete disappeared relatively earlier. With continuous water flow the surroundings of the aggregate eventually weakened, and the paste itself flowed out due to the leaching.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Exploratory Research
    Date (from‐to) : 2014/04 -2016/03 
    Author : Sugiyama Takafumi, KAJIWARA Kentaro, HITOMI Takashi, Henry Michael Ward
     
    X -ray CT method allows to visualize the geometrical spatial distribution in a given material. X-ray Diffraction, XRD is a analytical technique for identifying the crystalline material . A new technique to have these CT and XRD measurements as single unit has been developed in the beam line 28B2 of large-scale synchrotron radiation facility (Spring 8), Japan. It is named " Non-destructive Integrated CT-XRD method". This new technique has been applied to study hardened cementitious material. By using white X- rays , substance identification of low energy region unique to cementitious materials is possible and it is revealed to be an effective method by short time measurement. Distributions of cracking in cementitious material and aggregate can be visualized and the leaching of cement hydration products can be examined in a micrometer area.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (A)
    Date (from‐to) : 2013/04 -2016/03 
    Author : KISHI TOSHIHARU, MATSUDA Yoshinori, UEDA Hiroshi, KURASHIGE Isao
     
    In this study lots of experiments were carried out to elucidate the mechanisms on stagnations of liquid water seepage and salt ion permeation into hardened cement based concrete. Firstly, it was clarified by a series of experiments using micro and nano-channels on glass chip that diffusion of Chloride ion through condensed water in very fine pore less than 10nm diameter could be blocked due to electrical double layers formed on the wall. Secondary, their stagnations were experimentally verified by mortar specimens which were made from various powder admixtures and cured under different conditions. Then, it was confirmed that to use powder admixtures such as fly ash, silica fume and blast furnace slag which consumes free calcium hydro-oxide are beneficial to restrain liquid water permeation and related Chloride ion suction and diffusion through relatively larger connective pores. It was also suggested that air bubbles and liquid-water interface directly blocks and brakes them in pores.
  • 透視技術を核としたコンクリート構造物の革新的検査・健全度診断法の開発
    文部科学省：科学研究費補助金(基盤研究(B))
    Date (from‐to) : 2014 -2016 
    Author : 杉山 隆文
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)
    Date (from‐to) : 2012/04 -2015/03 
    Author : SATO yasuhiko, SUGIYAMA Takafumi, HASHIMOTO Katsufumi
     
    Concrete structures in hot spring area, underground structures, sewerage structures are suffered from mechanical actions such as earthquake and at the same time environmental actions. However, understandings on the mechanical characteristics of concrete under combined actions are not progressing. In this study, therefore, a mass transfer model; chemical reaction analysis method for prediction of cement hydrates and porosity change under environmental actions (Ca leaching and acid attach) and a fracture analysis method considering reduction in strength, Young's modulus and facture energy based on meso scale perspective are developed and those methods are integrated so as to predict the mechanical characteristics of semi-macro concrete.
  • 非破壊CT-XRD連成法の開発とセメント硬化体研究への応用
    文部科学省：科学研究費補助金(挑戦的萌芽研究)
    Date (from‐to) : 2014 -2015 
    Author : 杉山 隆文
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
    Date (from‐to) : 2011 -2013 
    Author : SUGIYAMA Takafumi, SHIMURA Kazunori, HENRY Michael
     
    Concrete is a primary construction material and hence has been used for varied types of structural members under diverse environments. It has been found that some concrete structures exhibit deterioration with cracks and alteration. For upgrading these degraded concrete the technology of diagnosis needs to be further developed first so that one can take next proper action for repairing. Visualization technique is now popular because rational evaluation can be made through image analysis and similar methods. To do so a X-ray Computed Tomography (XRCT) is considered promising tool. It can enable to obtain three dimensional images of internal microstructure and cracks. Then this research aims to clarify the capacity of the XRCT using mortar specimens. It was found that the 3D crack image could be obtained and the crack geometry such as crack width distribution with 10 micrometers or larger was quantified.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
    Date (from‐to) : 2009 -2011 
    Author : SATO Tsutomu, MICHIBAYASHI Katsuyoshi, NAGANUMA Takeshi, SUZUKI Masakazu, UEDA Akira, SUGIYAMA Takafumi, MIYASHITA Sumio, SUNAMURA Michinari, FUKUSHI Keisuke, TANAKA Shigeyasu
     
    Study on geo-and bio-resource science and technology learnt from the processes in hyperalkaline springs at Oman was conducted by geologists, geochemists, biologists, engineers to understand geological condition and geo-scientific impact of hyperalkaline springs, adaptation mechanism of microorganisms and fish for hypealkaline condition, long-term stability of natural concrete and effective storage of CO_2 in geological strata. From the results of this study, the following points were cleared ; 1) petrology and structure of geology for production of hyperalkaline springs, 2) kinetics of carbonate formation at the hyperalkaline springs, 3) role of the aragonite and monohydro-calcite on anion migration in groundwater, 4) the highest δD value of hyperalkaline water, 5) existence of new micooganisms and their genes, 6) existence and adaptation to hyperalkaline water of freshwater fishes and frog, 7) strength and long term stability of natural concrete at Oman.
  • 文部科学省：科学研究費補助金(挑戦的萌芽研究)
    Date (from‐to) : 2009 -2010 
    Author : 杉山 隆文, 志村 和紀
     
    微焦点(マイクロフォーカス)X線CTおよび大型放射光施設(SPring 8)における放射光X線CTを使用して、コンクリートの空隙構造の立体的可視化に向けた独創的で新規性のある技術を開発した。使用した装置は、それぞれ500ナノから10ミクロンまでの高分解能を有しており、これだけの広範囲かっ精度の高い分解能を有する装置を用いて、セメント硬化体の空隙構造を解析した研究は他には見当たらない。AEモルタルの空隙径分布および凍結融解作用によるひび割れ進展の様子を立体的に可視化することに成功した。実構造物コンクリートから採取したコア試料について、空隙構造を立体抽出し、空気量、空隙径分布、エントラップドエアに起因する粗大空隙の分布状況を調べた。また、竣工後6年半経過後であるがフライアッシュ粒子の存在を画像で捉えることができた。同一モルタル試料に対して、各装置を用いて空隙構造を解析して、耐凍害性の観点から空気量および空隙径分布を比較した。高分解能なほど微細空隙が抽出できるが、全体空気量に占めるこれら空隙体積割合は大きくないものの、気泡間隔係数の精度の良い算定に寄与すると考えられた。CT値やX線線吸収係数のヒストグラムから、空隙や水和物同定する際の閾値について調べ、さらに多様な材料特性を有する試料に対して、同一手法の有用性を調べることが必要であるとした。さらに、荷重作用によるひび割れ分布の様子を...
  • 日本学術振興会：科学研究費助成事業 特別研究員奨励費
    Date (from‐to) : 2008 -2009 
    Author : 杉山 隆文, PROMENTILLA Michael Augeb, PROMENTILLA Michael Angelo Baliwag
     
    本研究は,X線CT法をコンクリートの耐久性問題へ応用するために実施した.つまり,コンクリートの空隙構造と劣化現象の関係を調べるために,先ず高分解能X線CT撮影による直接観察を実施することで三次元空間における空隙径分布や空隙の連続性を定量化した.また,コンクリート構造物における劣化要因としては凍害およびカルシウムの溶出を対象とした. 凍害については,AE減水剤やAE剤を添加したAEモルタルの空隙構造を定量的に調べ,空隙構造と凍結融解作用の繰り返しによるスケーリングやひび割れ発生との関係を調べた.X線CTはマイクロフォーカスX線源を有する装置を用いた.その結果,AEモルタル中には,空隙径が40～50μmをピークとして300μmに及ぶ空隙構造であることを明らかにした.また,三次元空間における気泡間隔係数を,ASTM法の計算式を準用して算出した.AEモルタルでは200μm以下となり,平面解析から得られた値とほぼ対応した.さらに凍結融解作用によって生じたひび割れの長さや分布状態を視覚化した. 溶出に伴うセメントペーストの空隙構造の変化について,大型放射光施設(SPring-8)を利用して既に所得しているデータを詳細に分析することで,EPMAによるカルシウム-シリカ比と空隙の粗大化の関係を明らかにした.SPring-8は,サブミクロンレベルの空隙構造を把握するのに適しており,本研究ではピクセルサイズが0.5μmの場合の関係を示している.
  • Ministry of Education, Culture, Sports, Science and Technology：Grants-in-Aid for Scientific Research(基盤研究(B))
    Date (from‐to) : 2007 -2009 
    Author : Takafumi SUGIYAMA, Kazunori SHIMURA
     
    Methodology to construct environment-friendly and durable concrete structures in marine cold regions was studied. Coal ash that is a by-product in thermal power plants was used for cement and sand replacement in mixing concrete. In this way concrete with coal ash showed higher durability against salt attack and freezing and thawing cycles. Integrated design to achieve both aspects was proposed.
  • 文部科学省：科学研究費補助金(萌芽研究)
    Date (from‐to) : 2007 -2008 
    Author : 杉山 隆文, 志村 和紀
     
    コンクリートの微細構造を三次元で抽出するために、放射光X線CTおよびX線マイクロCTによる画像計測手法を開発することを目的に研究を実施した。画像解析においては、一般的に、試料から一部を抽出して解析を行うが、抽出する要素が試料全体の特性を表わしていることが不可欠である。そこでREV(representative elementary volume)解析に基づいて代表要素を抽出し、この抽出領域の特性が試料全体の特性を代表しているかについて研究した。すなわち、試料全体を代表する標本を抽出できるように、十分小さくかつ空隙を巨視的に捉えられるようにREVの最適値に関して研究を実施した。本研究の範囲内で得られた知見は、次の通りである : (1)VOIのサイズが小さいほど抽出位置による空隙率のばらつきが大きいことが観測された。(2)400^3voxels以上で空隙率、標準偏差とも一定値に収束したことから、REVの最適値はその最小値を採用して、400^3voxelsすなわち200^3(μm)^3と推測した。次に、取得したデータを演算処理して得られた画像データを用いて、空隙構造の定量化指標を決定するためにランダムウォークシミュレーション法の適用を引き続き研究した。使用した供試体は、普通ボルトランドセメントを用いたセメントペーストである。材齢を2、7、28日として、空隙構造について、空隙率、連続...
  • Ministry of Education, Culture, Sports, Science and Technology：Grants-in-Aid for Scientific Research(基盤研究(B))
    Date (from‐to) : 2005 -2006 
    Author : Yukikazu TSUJI, 睦好 宏史, 杉山 隆文, 岸 利治
     
    In this study, in order to experimentally investigate the flexural behaviors of high performance composite structures, trial combinations of high strength expansive concrete and fiber reinforcements were carried out. Fiber reinforcements consist of short fibers and continuous fiber reinforcements. A depth of reinforced concrete member is limited to 10 cm. Target compressive strength of expansive concrete is larger than 80N/mm^2. High strength expansive concrete can be applied to composite steel structures for the purpose of not only to protect steel corrosion but also to introduce chemical ...
  • Ministry of Education, Culture, Sports, Science and Technology：Grants-in-Aid for Scientific Research(基盤研究(B))
    Date (from‐to) : 2004 -2006 
    Author : Takafumi SUGIYAMA, 山田 一夫, 辻 幸和
     
    This research aimed at following objectives;・Ionic Transport in Concrete Influential on Interface Chemistry・Determination of Effective Diffusion Coefficient of Surface Coating and Restoration Materials by Migration Technique・Chloride Ingress in Surface Treated Concrete・Interface Resistivity of Concrete with Surface Treated Materials・Accelerated Leaching of Calcium Ions in Concrete by Migration Technique・Alternation of Bentonite by Contact with Concrete Using Migration TechniqueBased on this research primarily findings were as followed;(1)Effective diffusion coefficients of polymer cement mo...
  • 文部科学省：科学研究費補助金(基盤研究(C))
    Date (from‐to) : 2005 -2005 
    Author : 辻 幸和, 庄谷 征美, 坂井 悦郎, 氏家 勲, 岸 利治, 杉山 隆文
     
    メンテナンスフリーで500年程度の大深度地下施設や海峡長大橋および一般の各種海洋構造物等、また設計耐用期間が数万年という放射性廃棄物埋設処分施設といった各種の超耐久性を保持する社会基盤施設について、大気中だけでなく、海中や地中の各環境条件下において、コンクリート構造物の劣化の誘因となる、溶脱、塩害、凍害の現象について、これまでの研究成果をとりまとめた。そして、500年程度の長期間と数万年という超長期間に分けてこれらの劣化現象を定量的に評価する手法を調査し、今後解決すべき課題を抽出した。この場合に、各種の劣化因子がコンクリート中に侵入する挙動を解明することとなる。この際に、構築されたコンクリート構造物に大きな影響を及ぼす施工性の定量的な評価だけでなく、マスコンクリートの温度ひび割れおよび自己収縮と炭酸化収縮に起因するコンクリート構造物のひび割れの発生が避け得ない場合には、これらのひび割れやコンクリート構造物の施工欠陥のような初期欠陥が存在するコンクリート構造物全体の耐久性や安全性の評価手法を調査することが肝要である。また、古代ローマコンクリートなどを調査してナチュラルアナログの手法を採り入れることも、超長期間の劣化現象を定量的に評価するためには不可欠である。このようなこれまでに世界の研究者や技術者が採り上げなかった研究課題について調査研究して、超耐久性コンクリート構造物の構築手...
  • 文部科学省：科学研究費補助金(萌芽研究)
    Date (from‐to) : 2004 -2005 
    Author : 辻 幸和, 栖原 健太郎, 杉山 隆文
     
    本研究は、打込み時から凝結硬化時にコンクリートに生じる沈下ひび割れを治癒するため、膨張コンクリートを基本にして膨張作用の持続期間を遅延剤や超遅延剤等により延長することにより、どのレベルまでがコンクリートの自己治癒により補修されるかを定量的に評価することを試みた。まず、膨張材を2種類とその使用量を3種類それぞれ用いて、膨張コンクリートの膨張量の発現性状を試験した。試験体は、JIS A 6202(コンクリート用膨張材)附属書2(参考)に規定されているA法一軸拘束器具を用いた。その後、沈下ひび割れの発生を模擬した試験体を用いて、沈下ひび割れへの自己治癒効果を実験した。試験体は、幅が15cm、高さが20cm、長さが75cmで、試験体中央にかぶりを3種類に変化させて直上に沈下ひび割れを発生させるようにD13鉄筋を配置したものである。ひび割れの発生およびその後の自己治癒の効果は、打込み直後から鉄筋に貼付したひずみゲージにより追跡した。材齢28日に実施した曲げ強度試験は、試験体の上下を反転させて、沈下ひび割れが引張側となるように設置して行ない、曲げひび割れ発生応力度により自己治癒の効果を定量的に判定した。以上の結果、膨張材を用いた膨張コンクリートを用いると、コンクリートに導入されるケミカルプレストレスの量以上に、沈下ひび割れを生じさせたはりの曲げひび割れ発生応力度が増加していることを確かめ...
  • Ministry of Education, Culture, Sports, Science and Technology：Grants-in-Aid for Scientific Research(基盤研究(A))
    Date (from‐to) : 2003 -2004 
    Author : Makoto HISADA, 岩波 光保, 杉山 隆文, 加藤 佳孝, 山口 明伸, 河合 研至
     
    The purpose of this study is to evaluate the durability of concrete through the nation-wide testing and local climate monitoring. The test has been started since 2003, and still continuing.From these investigations, following conclusion was clarified.(1)The climate condition at Tsukuba was much severe than that at Kurihama in both summer and winter. In other word, Tsukuba was colder than Kurihama in winter season, and Tsukuba was hotter than Kurihama in summer season.(2)Therefore, the compressive strength of concrete exposed in Tsukuba were remarkably influenced more than that in Kurihama.
  • Ministry of Education, Culture, Sports, Science and Technology：Grants-in-Aid for Scientific Research(基盤研究(B))
    Date (from‐to) : 2003 -2004 
    Author : Yukikazu TSUJI, 保利 彰宏, 睦好 宏史, 杉山 隆文
     
    In this study, in order to experimentally investigate the flexural and shear behaviors of the Partially Prestressed Concrete(PPC) structure with vertical construction joints, the bending strength tests are carried out for 45 beam specimens of size of 30cm×60cm×360cm. The parameters for the experimental work have been classified by the following factors ; 2 quality classes of the vertical joints, 35 and 70 N/mm^2 of compressive strength of concrete, the amounts of applied prestressing forces are 60% and 80% of the 0.2% offset yield strength of φ 13mm prestressing steel bar, the compressive s...
  • Ministry of Education, Culture, Sports, Science and Technology：Grants-in-Aid for Scientific Research(基盤研究(B))
    Date (from‐to) : 2002 -2003 
    Author : Kenji KAWAI, 枝松 良展, 小澤 一雅, 杉山 隆文, 鶴田 滋, 市川 牧彦, 枝松 良道
     
    The aim of this study is to develop an evaluation method of environmental impact of concrete in which an action toward effective uses of resources and sustainable development becomes practicable in terms of economical aspects. The development of an evaluation system of materials for concrete and the proposal of methods for evaluating environmental impact of concrete were discussed in this study.In the development of an evaluation system of materials, the effects of heavy metal leaching from concrete on environmental impact was investigated. As a result, it was found that current batch tests...
  • Ministry of Education, Culture, Sports, Science and Technology：Grants-in-Aid for Scientific Research(基盤研究(B))
    Date (from‐to) : 2002 -2003 
    Author : Hirotaka KAWANO, 河合 研至, 小澤 一雅, 坂井 悦郎, 久田 真, 杉山 隆文
     
    The purpose of this study is to evaluate the influence of leaching substances from concrete during construction. Cr^<6+>,Cu^<2+> and Zn^<2+> were selected as the main substances. In addition, the amount of leaching these substances were measured during construction site.As the results, following conclusions were summarized :1.Small amount of Cr^<6+> were measured in construction site, for example, in breeding water, washing water. However, no substances were leached when concrete structures were in service.2.Basically, the amount of were quite small. Therefore, too much care against the lea...
  • 文部科学省：科学研究費補助金(基盤研究(C))
    Date (from‐to) : 2002 -2002 
    Author : 杉山 隆文, 下村 匠, 中村 光, 山田 義智, 佐藤 靖彦
     
    本研究の目的は,コンクリート構造物の性能をライフサイクルを通じて適切にかつ合理的に維持するための管理技術の構築について,共同で行う研究計画に対して企画調査を行うことであった.そこで本研究では,コンクリート構造物の劣化・損傷,性能低下,対策,対策後の性能回復・向上,再劣化,性能の再低下における時間的なサイクルの過程を定量的にシミュレートするモデルの開発に対して,材料の専門家と構造の専門家が共同して,現状の技術レベルおよび課題の抽出,モデル開発の有効性を中心に企画調査を実施することとした.本企画調査によって,補修材料のうち例えば,コンクリートの表面保護材料の耐久性が不明であり,補修後の維持管理やライフサイクルを通じたメンテナンスを考えた場合,早急にこれらの材料の耐久性の定量化が重要であることを明らかにした.これに対して,特に本研究では,シート接着鉄筋コンクリート供試体の電食試験結果と,シートの塩化物イオン拡散係数を仮定した数値解析結果とを比較することにより,シートおよび樹脂層の拡散係数を導出し,時間軸における評価手法の開発の妥当性を検討した.さらに,断面修復材のうち高耐久性のある材料についても電気泳動法によって塩化物イオン拡散係数を算出し,耐久性の合理的な評価の可能性を検討した.一方,特に厳しい海洋環境下や凍結融解作用下で劣化したコンクリート構造物の補修,補強や再劣化の実態調査で...
  • 文部科学省：科学研究費補助金(奨励研究(A), 若手研究(B))
    Date (from‐to) : 2001 -2002 
    Author : 杉山 隆文
     
    コンクリートの細孔溶液中でのイオンの拡散移動に対して,その駆動力を電気化学的ポテンシャルとして捉え,単なる濃度拡散力に限らず電気力の影響も含めるために,Onsager現象係数および一般化されたFickの法則から各イオン種の拡散現象を定量化する相互拡散モデルを構築した.つまり,コンクリート中のイオン移動現象の解明にあたって,多種類のイオン群でしかも比較的高濃度な溶液中の各イオンの移動を定量化するために必要な拡散係数の導出にあたり,相互拡散係数の概念を取り入れることに成功した.そして,分子論に立脚した相互拡散モデルの適用性をさらに詳細に調べるために,実験から得られたデータに基づいて各定数を定式化した.本研究によって開発した相互拡散モデルを用いて,細孔溶液中の塩化物イオン,硫酸イオン,アルカリ金属イオン,カルシウムイオンの移動について,過去に個別に行われたデータを収集・整理・比較しながら,モデルとの適合性を詳細に調べた.この結果から,コンクリート構造物の塩害,化学的侵食,アルカリ骨材反応,溶脱による劣化を支配しているイオン種の細孔溶液中での挙動を統一して説明できる可能性を見い出し,今後の更なる高度化への課題を抽出した.さらに,環境負荷低減に資する研究としての意義を探るために,相互拡散モデルの汎用性に関してに,六価クロムなどコンクリートに含有される微量成分についても拡張が可能かを検討...
  • 文部科学省：科学研究費補助金(萌芽的研究, 萌芽研究)
    Date (from‐to) : 2001 -2002 
    Author : 辻 幸和, 保利 彰宏, スプラティック グプタ, 杉山 隆文
     
    本研究では、膨張コンクリートを用いて打込み時から数時間に生じる沈下ひび割れをどのレベルまで、コンクリートの自己治癒により補修されるかを、実験を行い定量的に把握することを試みた。まず、膨張材を2種類とその使用量を3種類それぞれ用いて、水結合材比を変えた膨張コンクリートの膨張量の発現性状を試験した。試験体は、JIS A 6202(コンクリート用膨張材)附属書2(参考)に規定されているA法一軸拘束器具および鉄筋の配置方法を3種類に変化した鉄筋コンクリートはりを用いた。その後、沈下ひび割れへの自己治癒効果を曲げ強度実験により検討した。沈下ひび割れの発生を模擬した試験体は、幅が15cm、高さが20cm、長さが60cmで、試験体中央にかぶりを変化させて直上に沈下ひび割れを発生させるようにD13鉄筋を配置したものである。ひび割れの発生およびその後の自己治癒の効果は、鉄筋に貼付したひずみゲージにより追跡した。材齢28日に実施した曲げ強度試験は、上下を反転させて、沈下ひび割れが引張側となるように設置して、曲げひび割れ発生応力度より定量的に判定した。以上の結果、沈下ひび割れの発生レベルにより異なるが、膨張コンクリートを用いると、沈下ひび割れを自己治癒していると判定できることを確かめた。すなわち、コンクリートに導入されるケミカルプレストレスの量以上に、沈下ひび割れによる曲げ強度等の性状が改善されて...
  • Ministry of Education, Culture, Sports, Science and Technology：Grants-in-Aid for Scientific Research(基盤研究(B))
    Date (from‐to) : 1999 -2001 
    Author : Takumi SHIMOMURA, 佐藤 靖彦, 杉山 隆文, 中村 光, 徳重 英信, 今野 克幸
     
    The objective of this research project is to develop an analytical system that can predict performance of concrete structures subjected to various load and environmental actions. Following results were obtained.1) A computer program for numerical simulation of time-dependent performance change of RC bridges subjected to chloride attack was developed. It can predict effectiveness of some rehabilitation techniques as desalination method and retrofitting of CF sheet on service life of structures.2) Material models in the computational system mentioned above were improved, which are material tr...
  • Ministry of Education, Culture, Sports, Science and Technology：Grants-in-Aid for Scientific Research(基盤研究(C))
    Date (from‐to) : 1997 -1998 
    Author : Yukikazu TSUJI, 橋本 親典, 杉山 隆文
     
    Reinforced concrete beams and partially prestressed concrete beams having a vertical construction joint were produced by using both ordinary strength concrete and super high strength concrete. The vertical construction joint was placed in a shear span of the beam. A flexural loading test was carried out to take cracking behaviors and stirrup's strains of the beam. Strengthening effect of placing steel plates and prestressing to the beam was also investigated. The test results are as follows.1) The reinforced concrete beam with ordinary strength concrete was cracked firstly in the vertical c...
  • 文部科学省：科学研究費補助金(基盤研究(C))
    Date (from‐to) : 1996 -1996 
    Author : 辻 幸和, 杉山 隆文, 橋本 親典
     
    本研究では、主として断面が幅15cm、高さ20cmの矩形断面で、長さが120cmの小型RCはりを用いたが、断面が幅25cm、高さ40cmの矩形断面で、長さが360cmの大型RCはりも作製し、寸法効果についても検討した。なお、初期欠陥部に被覆する鋼板の厚さと長さは、RCはりの断面寸法に比例させた。鉛直打継目をせん断耐力が最も低下するせん断スパン中央に設けた小型RCはりを作製し、鉛直打継目を鋼板を主体とする金属板で被覆した場合の、鋼板幅、鋼板厚さ、コンクリートと鋼板の間のグラウト強度、金属板の種類がそのはりの曲げおよびせん断性状に及ぼす影響について、実験的に検討した。その結果、鉛直打継目を鋼板で被覆することにより、鉛直打継目が存在しないRCはりと比較しても、はりの耐力は増加し、破壊形式はせん断圧縮破壊から曲げ引張破壊へと移行した。また、各種試験状況の中でも、鋼板幅および鋼板厚さが、RCはりの力学的性状に大きく影響を及ぼすことが示された。そして、鋼板による補強のメカニズムについても考察を加えた。また、これらの現象を、大型のRCはりについても確かめた。更に、これまでに開発した緊張材との付着が完全な場合および付着がない場合についてのPRCはりの曲げ性状を解析するプログラムを、鉛直打継目があることを、また被覆鋼板があるこをそれぞれ考慮した曲げ性状の解析プログラムに改良して、実験結果と良い...
  • 文部科学省：科学研究費補助金(一般研究(C))
    Date (from‐to) : 1995 -1995 
    Author : 辻 幸和, 杉山 隆文, 橋本 親典
     
    プレストレスの導入率を50%と80%の2種類に変えたポストテンション方式でPCグラウトの圧縮強度を20, 50, 80MPaの3種類とPCグラウトを注入しないプレストレスト鉄筋コンクリート(PRC)はりの曲げ載荷試験を行い、緊張材の付着特性がPRCはりの曲げ性状に及ぼす影響について実験的に検討した。またPRCはりには、プレテンション方式とPC鋼より線の代わりに連続繊維補強材を用いたものも含めた。本研究により、以下のことが明らかになった。(1)プレストレスの導入率を通常用いる80%にした場合、高強度グラウトを用いれば高強度のPRCはりの曲げ性状を改善できた。特に、ひび割れやたわみは、顕著に改善できた。(2)プレストレスの導入率を50%と低く設定した場合や連続繊維補強材を用いた場合、80MPaの高強度グラウトを用いても緊張材とグラウトの一体化が不十分で、通常グラウトを用いたときと曲げひび割れやたわみには大きな差は認められなかった。しかし、曲げひび割れ発生荷重や最大荷重などは大きくなった。(3)緊張材とPCグラウトが不完全な付着状態の場合、付着のレベルを表す補正係数αの概念を用いることにより、PRCはりの曲げ性状の算定は可能である。(4)アンボンドのPRCはりの曲げ性状は、従来のアンボンドPCはりの解析で用いられている部材長の全長にわたるPC鋼材とPC鋼材位置におけるコンクリートの...
  • Ministry of Education, Culture, Sports, Science and Technology：Grants-in-Aid for Scientific Research(試験研究(B))
    Date (from‐to) : 1993 -1994 
    Author : Chikanori HASHIMOTO, 丸山 久一, 杉山 隆文, 辻 幸和
     
    A pulsatile flow of concrete flowing in pipe will adversely affect the property of the fresh concrete after being pumped as well as the pumping pipe itself. In addition, the noise resulting from the pulsating concrete flow in pipe might exceed an acceptable level from environmental points of view in the job site.This research project has been conducted to develop a novel system for pumping concrete with a minimizing degree of the pulsation in the pipe. A pumping devise designed on a small scale has two hydraulic cylinders : one for a main stream and the other for a supplemental stream, resp...
  • コンクリート-ベントナイト複合構造体の変質機構の解明
  • コンクリート構造物のライフサイクルマネジメント
  • セメント水和物系システムの移動現象論
  • Degradation mechanisum of concrete bentonite composite system
  • Performance-Based Design of Concrete Structures
  • Transport Property of cement hydrated system

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