MF研究者総覧

研究者データベース

詳細
北垣　亮馬(キタガキ　リヨウマ)
工学研究院　建築都市部門　先端空間性能
教授
researchmap個人ページ
Last Updated :2024/05/09

基本情報

所属

  • 工学研究院　建築都市部門　先端空間性能

職名

  • 教授

学位

  • 博士（工学）（2006年03月 東京大学）

ホームページURL

科研費研究者番号

  • 20456148

ORCID ID

J-Global ID

研究キーワード

  • コンクリート工学, 補修, 高分子, 断熱材, 廃棄物資源循環, 二酸化炭素, カーボンリサイクル,建築材料, 耐久性   

研究分野

  • 社会基盤（土木・建築・防災） / 建築構造、材料 / コンクリート工学, 補修, 高分子, 断熱材, 廃棄物資源循環, 二酸化炭素, カーボンリサイクル,建築材料, 耐久性

担当教育組織

職歴

  • 2022年04月 - 現在 北海道大学 大学院工学研究院 教授
  • 2018年09月 - 現在 北海道大学 大学院工学研究院 准教授
  • 2011年04月 - 2018年08月 東京大学 大学院工学系研究科 建築学専攻 講師
  • 2008年04月 - 2011年03月 東京大学 大学院工学系研究科 社会基盤学専攻 特任助教
  • 2006年06月 - 2008年03月 東京大学 大学院工学系研究科 社会基盤学専攻 特任研究員
  • 2006年04月 - 2006年05月 東京大学 大学院工学系研究科 建築学専攻 技術補佐員

学歴

  • 2003年10月 - 2006年03月   東京大学   大学院工学系研究科   建築学専攻 博士課程
  • 2000年04月 - 2003年09月   東京大学   大学院工学系研究科   建築学専攻 修士課程
  • 2001年09月 - 2002年09月   ウィーン工科大学
  • 1996年04月 - 2000年03月   東京大学   工学部   建築学科

所属学協会

  • 日本建築仕上学会   日本コンクリート工学会   土木学会   日本建築学会   

研究活動情報

論文

  • Yoobin Leem, Ryoma Kitagaki, Takato Ishida, Hideaki Hagihara
    Developments in the Built Environment 18 100429 - 100429 2024年04月
  • Mylvaganam Nithurshan, Yogarajah Elakneswaran, Yuya Yoda, Ryoma Kitagaki, Naoki Hiroyoshi
    Construction and Building Materials 2024年04月
  • Naohiko Saeki, Luge Cheng, Ryo Kurihara, Takahiro Ohkubo, Atsushi Teramoto, Yuya Suda, Ryoma Kitagaki, Ippei Maruyama
    Cement and Concrete Composites 146 2024年02月 
    Finely ground hardened cement pastes (hcp) under 75 μm were carbonated at varying relative humidities (23–95 % RH) to determine the carbonation rate that minimized CO2 diffusion in the bulk paste. The amounts of portlandite (CH) and calcium carbonate (CC) polymorphs were quantified, and the decalcification and decomposition of C-A-S-H were analyzed using TGA, XRD, mass balance calculation, FTIR, and 29Si MAS NMR spectroscopy. A higher RH accelerated the reaction rate, and CH dissolution stopped midway at 58 % RH or below because of the loss of connectivity with the pore solution in the CC shell around CH. The precipitated CC phase included calcite at high RH, whereas all three polymorphs formed at 58 % or lower RH; amorphous CC were detected at low RH. The decalcification and decomposition of C-A-S-H were observed at 45 % or higher RH; it was rarely carbonated at 33 % or lower RH.
  • Siventhirarajah Krishnya, Kirushnapillai Kopitha, Yuya Yoda, Ryoma Kitagaki, Yogarajah Elakneswaran
    Cement and Concrete Composites 146 2024年02月 
    This study established a new transport model by using the COMSOL-IPHREEQC interface to simulate the changes in the morphology of hydrated cement paste due to the diffusion of carbon dioxide and chloride ion. A series of constitutive models such as the cement hydration model (to compute the dissolution rate of each clinker mineral), thermodynamic model (to perform the hydration reaction, reaction due to transport of ions, chemical and physical adsorption of chloride ion during the chloride ion ingression and dissolution rate of calcium-silica-hydrate (C–S–H) simultaneously with portlandite for the carbonation), porosity determination, and COMSOL Multiphysics (for the calculation of transport problems) were integrated using MATLAB language to determine the pore solution chemistry, hydrates assemblage, and porosity of the cement paste exposed to aggressive environments. During the diffusion of carbon dioxide gas, the decalcification of C–S–H was realistically considered by assuming that the Ca/Si ratio of C–S–H decreased from 1.67 (Jennite type C–S–H) to 0.67 (Tobermorite C–S–H), and then from 0.67 to 0 (silica gel). The proposed integrated platform was well verified with different sets of reported and raw experimental results and existing models, indicating a realistic predictability for chloride ion ingression and carbonation. The developed model discloses the effect of coupling the progression of hydration with reaction due to the transport of ions by using the free chloride ion profile and phase assemblages during the chloride ion ingression.
  • Sujeong Pyeon, Gyuyong Kim, Byungcheol Choi, Moonkyu Kim, Ryoma Kitagaki, Heesup Choi, Jihoon Kim, Jeongsoo Nam
    Case Studies in Construction Materials 19 2023年12月 
    This study investigated the potential of waste glass beads (WGB), a recycled porous lightweight material derived from waste glass, to enhance long-term curing of moisture-saturated cementitious construction materials. The macroscopic properties and microstructure development of a cement composite material blended with two types of WGB––spherical (B) and crushed (CB)––were analyzed. The primary objective was to provide practical guidelines for optimizing WGB utilization as a moisture release medium and thus contribute to sustainable concrete production by exploring waste glass applications. This study demonstrated the potential of WGB for improving strength and void structure and could help enhance the long-term durability of cement composites. Valuable insights were gained regarding the surface roughness and specific surface areas alongside curing methods to maximize WGB's effectiveness. The key contributions are as follows: (1) varying effects on high-strength concrete (HSC) strength with increased WGB content and surface roughness and specific surface areas were analyzed; (2) a proportional relationship between closed pore volume and modulus affecting macroscopic properties was revealed; (3) insights into hydration product presence in the ITZ and its relationship with WGB moisture content were gained; and (4) notable improvements in indentation tests for specimens with WGB were achieved, indicating enhanced ITZ hydration and increased density within both ITZ and paste.
  • Kaishi Kojima, Jihoon Kim, Ryoma Kitagaki, Yukio Hama
    Construction and Building Materials 403 2023年11月 
    In ordinary hardened cement, the pore structure changes with microstructural changes due to repeated dry and wet cycles. However, the calcium-silicate-hydrate (C-S-H) produced in blended cement is different from that of ordinary cement because blast furnace slag and fly ash are used in blended cement. In this study, microstructural changes in ordinary cement and hardened blast-furnace cement, which have different compositions of C-S-H, due to repeated dry and wet cycles at high temperatures, were analyzed by solid-state nuclear magnetic resonance (NMR) for structural changes in the products, and by time domain NMR and mercury intrusion porosimetry for changes in moisture and pore structure in the hardened cement. As a result, it was confirmed that the degree of coarsening of capillary porosity in blast-furnace cement was lower than in ordinary cement due to drying and repeated dry-wet cycles. This is believed to be because the aluminum contained in the blast furnace slag of the blast-furnace cement, which is present in the interlayer, improves the resistance of the C-S-H layer to compaction, resulting in less change in the pore structure. This study is expected to contribute to fundamental research on hardened cement in the future.
  • Kirushnapillai Kopitha, Yogarajah Elakneswaran, Ryoma Kitagaki, Ryosuke Saito, Masato Tsujino, Akira Nishida, Hisanori Senboku, Naoki Hiroyoshi
    Chemical Engineering Journal 475 146067 - 146067 2023年11月 
    The escalating release of CO2 into the atmosphere has turned the matter of global warming into a pressing issue. Therefore, direct air capture (DAC - capturing CO2 from the environment) using buildings and infrastructure made of cement-based materials as “synthetic trees” could be an effective approach, given the growing urbanization trend. This study proposed a new technique to use N-methyldiethanolamine (MDEA) in cement-based materials to sequestrate CO2 from the environment. It has significant potential and flexibility compared to existing CO2 capture technologies, particularly given the limitations of CO2 mineralization in cement-based materials with slow kinetics. Furthermore, this study examined the resulting microstructural changes and reaction mechanisms of each hydrated phase, such as Ca(OH)2, calcium-silicate-hydrate (C-S-H), and hydrated cement, due to the addition of MDEA after carbonation. The study also investigated the effect of different percentages of amine on the carbonation of Ca(OH)2 under accelerated conditions, followed by the natural carbonation of cement paste coarse particles. The results showed that a 10% MDEA of water volume is optimal for CO2 capture in cement-based materials. Beyond this percentage, MDEA loss on the surface of solid particles was observed by thermogravimetric analysis (TGA). The study also examined the changes in microstructure, chemical environment, pH, and calcite formation in the cement paste samples with one side exposed to accelerated carbonation. MDEA increased calcite formation by 1.5–2 times compared to the samples that did not contain MDEA. Additionally, aragonite and calcite were formed when MDEA was present, whereas the samples without MDEA only formed calcite.
  • Takato Ishida, Ryoma Kitagaki, Yogarajah Elakneswaran, Junji Mizukado, Hideyuki Shinzawa, Hiroaki Sato, Hideaki Hagihara, Ryota Watanabe
    Macromolecules 56 3 883 - 891 2023年01月18日 
    To study the degradation of thermosetting polymers, we apply a novel method to simultaneously study the chemical structural changes and network topology: evolved gas analysis-mass spectrometry combined with principal component analysis (EGA-MS-PCA). This technique was applied to thermo-oxidative aging of an epoxy/amine network. The signals of various pyrolyzates remain overlapped in the complicated EGA-MS profiles. The key fragments of thermally evolved gases derived from the components of the network are effectively selected by PCA from the complicated EGA-MS profiles. EGA-MS-PCA provides information on the network structure: (i) the oxidized fraction of cross-links (i.e., chemically damaged cross-links), (ii) the relative quantification of unbonded chains, and (iii) the formation of dangling chains. The proposed technique can simultaneously characterize chemical degradation and network structural properties. This characterization technique can be utilized as a generally applicable tool for determining the structural durability of thermosetting polymers.
  • K. Kopitha, S. Krishnya, Y. Elakneswaran, R. Kitagaki, Y. Yoda, M. Tsujino, A. Nishida
    Lecture Notes in Civil Engineering 362 LNCE 149 - 159 2023年 
    The durability of the structures is the main concern in the field of engineering. Reinforcement corrosion is the most common cause of concrete structural deterioration. Corrosion of reinforcement results primarily from chloride ingress and carbonation. Cementitious materials are prone to carbonation as carbon dioxide is present everywhere in the atmosphere. For the durability prediction of cement-based materials, it is crucial to know the effect of carbonation on the microstructure of the cement matrix. This study examines how carbonation affects the microstructure of cement paste made up of Ordinary Portland Cement (OPC) with water-to-cement ratios (w/c) of 0.3, 0.4, and 0.5 with the help of the experiments and the newly developed model predicting the hydration products and porosity of the cement paste during the CO2 gas diffusion. As part of this study, phenolphthalein was used to determine the carbonation depth. In addition to identifying the hydrated and carbonated products using X-Ray Diffraction (XRD) and Thermal Gravimetric Analysis (TGA), changes in microstructure were detected through Scanning Electron Microscope (SEM). Furthermore, the microstructures of cement paste samples that have been exposed to 5% carbon dioxide concentration for four months were compared. Carbonation products consist predominantly of calcite type polymorph of calcium carbonate, as revealed by XRD. Portlandite and C-S-H get carbonated simultaneously and the carbonation reaction increases with the increasing w/c in accordance with XRD and TGA results. Eventually, the experimental results of calcite and portlandite were compared with the predicted results from a newly developed COMSOL-IPHREEQC interface, and a better prediction of the numerical model was observed.
  • Mylvaganam Nithurshan, Siventhirarajah Krishnya, Yuya Yoda, Ryoma Kitagaki, Yogarajah Elakneswaran
    NanoWorld Journal 9 Special Issue 2 62 - 68 2023年 
    In recent years, cementitious materials and fibers have become widespread in concrete mixtures to enhance the mechanical and durability properties of engineering structures. However, incorporating such materials increases construction costs and requires extensive experimental trials to determine the optimal dos-age. Consequently, researchers have conducted studies to predict cement-based materials’ mechanical properties using various techniques to avoid costly and labor-intensive experiments. Due to computer programming and hardware advancements, microstructure-based computational modelling techniques have garnered researchers’ attention. Hence, this study aims to propose a multi-stage model that predicts the mechanical properties of cement paste using unique input parameters, such as the chemical properties of cement and curing conditions, by integrating the hydration process and microstructure development. In the initial stage (Stage 0), the volume fraction of hydration products is predicted considering the formation of calcium silicate hydrates (C-S-H) in two densities. After-wards, a representative volume element (RVE) for cement paste is developed in MATLAB based on the previous stage’s results (Stage 0). In the next stage, the RVE’s geometry is transferred to COMSOL Multi-physics via the Live Link™ tool for numerical analysis, where intrinsic mechanical properties are computed and verified with two independent experimental data sets. The verification showed that the proposed multi-stage model accurately predicts the compressive strength and Young’s modulus of cement paste with time. Therefore, this modelling approach can be extended to predict the material properties of mortar and concrete through upscaling.
  • Haruka Takahashi, Ippei Maruyama, Takahiro Ohkubo, Ryoma Kitagaki, Yuya Suda, Atsushi Teramoto, Kazuko Haga, Takahiro Nagase
    Journal of Advanced Concrete Technology 21 10 789 - 802 2023年 
    In this study, CO2 quantification was performed on various concrete binder and aggregates by back titration, thermogravimetric method, and combustion-infrared absorption method, and their mutual consistency and error factors due to material characteristics were investigated. The back titration measures CO2 directly and is considered the suitable method for both materials, although the effect of sulfide was a concern. On the other hand, the TGA method was revealed to have the possibility of underestimating or overestimating the CO2 determination because the oxidation of sulfides in blast furnace slag, combustion of unburned carbon in fly ash, and dehydration of clay minerals in aggregate overlapping with the temperature range of calcination of calcium carbonate. In the combustion-infrared absorption method, elemental or organic carbon encapsulated in aggregate particles may underestimate or overestimate the CO2 content. In blended cement, sulfur compounds may interfere with the infrared absorption of CO2 and overestimate the amount of CO2. Based on these results, back titration was considered the most suitable method for determining CO2 for concrete materials. It is essential to understand the characteristics of each sample contained and select appropriate methods for CO2 quantification of concrete materials and concrete.
  • Siventhirarajah Krishnya, Yogarajah Elakneswaran, Yuya Yoda, Ryoma Kitagaki
    RILEM Bookseries 43 686 - 696 2023年 
    The prediction of chloride ingression in cement-based material has gained a great deal of interest among researchers as it causes long-term structural damage in buildings by chloride-induced reinforcement corrosion. The Cl− diffusion in mortar is influenced by internal factors including pore-structure and hydrates which are determined by clinker properties, mixture recipe, and curing conditions and exposure conditions. The Cl− penetration in mortar leads to the modification of the microstructure and pore-solution due to the disequilibrium of the hydrates-pore solution system. Considering the complexity of the process by incorporating all aforementioned factors and interaction of Cl− with hydrates, a new model is herein proposed for predicting the microstructure of the mortar during the Cl− diffusion. In this work, the microstructure of mortar is considered as a three-phase material: aggregates, interfacial transition zone (ITZ) and bulk paste, and ITZ is realistically considered as high W/C paste compared to the initial W/C. The developed COMSOL-IPHREEQC model involves hydration model for calculating the dissolution of clinker in bulk paste and ITZ, thermodynamic model including the surface complexation model to predict the hydrates and the Cl− adsorption by hydrates, homogenization approach to compute the average hydrates, porosity, pore solution composition and diffusion parameters of the mortar and COMSOL Multiphysics to perform the transportation calculation. The predicted results are validated with experimental results available in the literatures to verify the reliability of the proposed model. The effect of ITZ on the penetration of Cl− is also assessed in this work.
  • Yoobin Leem, Sizuka Kojima, Ryoma Kitagaki
    Macromolecular Symposia 405 1 2022年10月 
    Foamed plastic insulations installed into buildings are now expected to be long-lasting materials. However, in recent years, it has been reported that foamed plastic insulations installed in high-humid environments, such as under waterproof sheets on a rooftop, absorb moisture, and subsequently increase thermal conductivity. This paper studies both moisture absorption and changes in physical properties of foamed plastic insulations after exposure to high humidity and discusses the moisture-induced deterioration based on the results of several experiments.
  • Takato Ishida, Ryoma Kitagaki
    MACROMOLECULAR SYMPOSIA 405 1 2022年10月 
    This work addresses to propose a model to reproduce accelerated aging results for polycarbonate. Four accelerated aging conditions are studied, including several light sources. In this study, aging behaviors are monitored by the yellowing index. Obtained simulations are well-tracked the aging data for four accelerated aging conditions. Besides, the features of accelerating environments by a phase plane plot are challenged to visualize.
  • Takato Ishida, Ryota Watanabe, Hideyuki Shinzawa, Junji Mizukado, Hideaki Hagihara, Ryoma Kitagaki, Yogarajah Elakneswaran
    Polymer Testing 112 107587 - 107587 2022年04月 
    A novel technique, in-situ infrared (IR) cure monitoring coupled with two-trace two-dimensional (2T2D) correlation analysis, is developed to probe the property-enhancement mechanism of a newly developed thermosetting nanocomposite comprising an acrylic-urethane network (AUN) and silica nanospheres (SNS). The IR spectra were collected in real-time during the curing process at 100 °C. We employ the 2T2D correlation analysis to identify the spectral variations of the interfacial interaction. The curing reaction initially proceeds throughout the sample solution. After the network percolation, the unreacted sites react near the SNS surface and yield additional hydrogen-bonded C[dbnd]O groups that interact with the surface silanol groups. The matrix–filler interactions play a key role in enhancing the hardness and thermal stability of the AUN/SNS nanocomposites by restricting the mobility of the polymer molecules. The proposed technique provides sequential mechanisms in the curing process and a picture of the interfacial interaction for the thermosetting nanocomposite system.
  • Takato Ishida, Emmanuel Richaud, Matthieu Gervais, Alain Gaudy, Ryoma Kitagaki, Hideaki Hagihara, Yogarajah Elakneswaran
    PROGRESS IN ORGANIC COATINGS 163 2022年02月 
    This study addresses the multiscale analysis of acrylic urethane networks (AUN). To establish the kinetic model for predicting AUN oxidation, this study considered the pure thermal oxidation of AUN at 160, 180, and 200 degrees C. Chemical changes were monitored using infrared spectroscopy. These indicated the presence of an imide, presumably generated from the oxidation of CH2 at the alpha-position of nitrogen. On the macromolecular and macroscopic scales, oxidation was shown to induce predominant crosslinking, leading to a drop in toughness (i. e., embrittlement). The novel kinetic model of AUN thermal aging was developed from a mechanistic scheme previously established for polyamide 11, by adding some extra paths of thermolytic alkyl radical formation, oxidative N-H bonds decomposition and coupling of aminyl radicals.
  • Takato Ishida, Ryoma Kitagaki, Hideaki Hagihara, Yogarajah Elakneswaran
    Polymer Testing 96 107123 - 107123 2021年04月 
    In this work, the role of moisture in photo-ageing was discussed for the case of an acrylic-urethane network. Ageing behaviours were characterised by Fourier transform infra-red spectroscopy, positron annihilation lifetime spectroscopy, sol-gel analysis, and differential scanning calorimetry. Two common features between dry and wet photo-ageing, namely, decrease in the mean free volume and increase in the glass transition temperature were observed as photo-oxidation progressed. The characteristics of the final internal structure of the wet photo-aged sample differed from those of the dry photo-aged sample. Although the dry photo-aged samples suggested network densification due to extensive crosslinking formation, wet photo-ageing led to an inhomogeneous structure wherein the average molar mass between crosslinks (at a scale of several nanometres) increased and some domains crosslinked at the sub-nanoscale. Considering the physical (plasticisation) and chemical (hydrolysis) effects induced by water, a possible mechanism for the evolution of the macromolecular architecture was proposed for photo-ageing in dry and wet environments.
  • Takato Ishida, Ryoma Kitagaki
    Polymers 13 5 820 - 820 2021年03月 
    Many natural exposure sites have been developed to ensure the reliability of materials intended for outdoor use. However, the effects of local climate on aging have not been completely understood. This study aimed to elucidate the regional characteristics of natural aging. Non-stabilized and stabilized polycarbonates were monitored in terms of their appearance (yellowing and loss of gloss) during natural weathering at five exposure sites (Tokyo, Kagoshima, Okinawa, Florida, and Arizona) in conjunction with climate fluctuation for up to 24 months. Three approaches were employed to characterize the natural aging behaviors: (i) modeling the rate function of degradation, (ii) evaluating the contribution ratio of individual degradational factors, and (iii) estimating the “synchronicity” by cross-correlation analysis with the climate dataset. The aging rates were the highest in Arizona and lowest in Kagoshima among the five exposure sites. First, prediction curves were constructed from the degradation rate function (variables: UV irradiation, temperature, and humidity), and these curves were found to agree well with the measured aging behaviors. Second, the exposure data in Arizona demonstrated strong temperature dependence, while those in Okinawa and Florida had stronger dependence on UV irradiation compared to other sites. Lastly, the synchronicity between UV irradiation and temperature was the highest in Arizona and lowest in Kagoshima, which can explain the significantly faster deterioration in Arizona and the slow deterioration in Kagoshima.
  • 任 裕彬, 北垣 亮馬
    日本建築学会技術報告集 27 65 93 - 98 一般社団法人 日本建築学会 2021年 

    Foamed plastic insulations installed into buildings are now expected to be long-lasting materials. However, in recent years, it has been reported that the foamed plastic insulation installed in the high-humid environment, such as under waterproof sheets on a rooftop, absorbs moisture and subsequently increases the thermal conductivity. The mechanism of moisture absorption is not sufficiently clear, and the test method for thermal conductivity of building insulating materials does not consider the influence of humidity. This study observed both moisture absorption and changes of physical properties of foamed plastic insulations after exposed at high humidity and discussed the moisture-induced deterioration.

  • Dayoung Oh, Takafumi Noguchi, Ryoma Kitagaki, Hyeonggil Choi
    RENEWABLE & SUSTAINABLE ENERGY REVIEWS 135 2021年01月 
    The rapid industrial development and global population growth of the past century have resulted in an exponential increase of resource consumption and thus caused elevated CO2 emissions that, in turn, are held responsible for global warming and associated environmental problems that require urgent solutions. Specifically, increase of cement production causes CO2 pollution and generates a significant amount of concrete waste. Waste concrete, the major component of construction waste, can be efficiently recycled and is mainly used as a roadbed or backfill material. However, as no further resource recycling is expected for waste concrete, more efficient and productive recycling systems are sought after. Herein, waste concrete powder is used to produce added-value inorganic building materials, namely recycled cement and solidification. The characteristics of recycled cement (manufactured through calcination) are evaluated in terms of free lime content, mineral composition, density, color, flow test and strength, and the performance of recycled cement is found to be identical to that of ordinary Portland cement. X-ray diffraction and compressive strength analyses of the solidification manufactured through hydrothermal synthesis show that blocks of the desired strengths can be produced by adjusting the degree of consolidation and curing conditions. Based on these results, this study proposes a concrete waste recycling system to reduce the amount of construction waste and prevent resource depletion.
  • Jihoon Kim, Ryoma Kitagaki
    CEMENT & CONCRETE COMPOSITES 114 2020年11月 
    In order to improve the durability of concrete structures, silicate-based impregnant have been used, but the chemical interaction mechanism is not clear. Silicate-based impregnant react with calcium hydroxide, which is formed during the process of cement hydration, and form compounds similar to a calcium silicate hydrate (C-S-H). This paper performs reaction experiments by Ca/Si ratio, and solid state nuclear magnetic resonance (NMR) and X-ray powder diffraction (XRD), fourier transform infrared spectroscopy (FT-IR) and Raman spectroscopy are conducted for observing chemical changes of cement paste with silicate-based impregnants. Based on the results of XRD, reduction of monosulfate phase was observed as well as the formation of C-S-H (tober-morite-like phase). Si-29 and Al-27 NMR spectra also correspond with the XRD results. Further, possibility of both Al/Si substitution and formation of a structure close to C-(A)-S-H (C-S-H containing Al) were observed. Therefore, silicate-based impregnant formed not only new C-S-H reacting with calcium hydroxide, but also influenced other hydrates.
  • Jihoon Kim, Ryoma Kitagaki
    CONSTRUCTION AND BUILDING MATERIALS 262 2020年11月 
    Silicate-based surface impregnation is used to improve the surface durability of concrete structures. This study employs various analysis tools to understand the relationship between cement-hydrate formation behavior and durability development upon the application of a silicate-based surface impregnant. Through simple surface immersion experiments, we evaluate the chemical properties and mass transfer resistance of modified surfaces and observe changes in carbonation related to these properties. We found that calcium silicate hydrate at the surface is produced due to the application of the silicate-based surface impregnant. However, we confirm that the penetration of carbon and carbonation of the surface layer are promoted due to changes in both the hydrate and physical properties of the modified surface. In addition, the chemical and physical changes in the surface layer due to the modification reduce the elastic modulus of the surface layer and have no effect on improving mass transfer resistance. These results could present a significant contribution to developments in concrete applications and allied fields. (C) 2020 Elsevier Ltd. All rights reserved.
  • Jihoon Kim, Ryoma Kitagaki, Heesup Choi
    Materials 13 19 4343 - 4343 2020年09月29日 
    Various methods for repairing and modifying concrete surfaces have been proposed and applied to improve the durability of existing concrete structures. Surface modification through forced carbonation is a method of densification that forms calcium carbonate in the pores on the surface of concrete to improve its durability. In this study, to evaluate the applicability of this surface modification method to existing buildings, a series of experiments was conducted in which mortar specimens were repeatedly immersed in a carbon dioxide nanobubble aqueous solution. By evaluating the weight change and absorption rate, it was determined that the higher the water/cement ratio of the mortar specimen, the higher the pore filling effect owing to immersion in the carbon dioxide nanobubble aqueous solution. In addition, the effect of clogged pores generated by the precipitation of calcium carbonate was confirmed, and it was found that the higher the water/cement ratio of the mortar specimen, the higher the pore filling effect due to clogging. We believe that our findings contribute to the development of research and construction practices associated with concrete repair and restoration.
  • Takato Ishida, Ryoma Kitagaki, Ryota Watanabe, Hideaki Hagihara, Yogarajah Elakneswaran, Hideyuki Shinzawa
    POLYMER DEGRADATION AND STABILITY 179 2020年09月 
    The molecular architecture changes of crosslinked urethane during photo-oxidation was investigated by Fourier transform infrared spectroscopy (FTIR) in combination with two-dimensional (2D) correlation analysis. The 2D correlation FTIR spectroscopy provided insight into molecular architectural dynamics during photo-aging, where the sequential order of peak changes was determined upon perturbation with photo-aging. Photo-oxidation was monitored from the decrease in the peak intensity at 1537 cm(-1) (attributed to the urethane group) and the generation of the hydrogen bonded C=O groups at 1698 cm(-1) immediately after urethane decomposition. Several notable peaks appeared (1712,1650, and 1750 cm(-1)) in the later stages, which were attributed to the free photo-oxidative product. In summary, photo oxidation involved a cleavage of urethane crosslink and generation of end groups that formed hydrogen bonds with surrounding hydrogen bonding sites. Further degradation of the free photo products was observed likely because of the small number of accessible hydrogen bonding sites due to the increasing heterogeneity of the internal structure. (C) 2020 Elsevier Ltd. All rights reserved.
  • Tetsushi Miyoshi, Ryoma Kitagaki, Takafumi Noguchi
    JAPAN ARCHITECTURAL REVIEW 3 3 307 - 317 2020年07月 
    In this paper, we analyze the corrosion of reinforcements as indices of processes of the super-long-term combined deterioration of reinforced concrete building groups with finishing materials, pre-induced cracks, and maintenance. Specifically, we systemize specifications for finishing materials by permeability, deterioration mechanisms, and demeanor after repairs, and adopt agent-based modeling for decision-making of specifications for structures, finishing materials, and repair methods whose characteristics are based on generic products. We calculate the corrosion of reinforcements in general parts by Yonezawa's method and in cracks by the corrosion speed of bare steel, and assume minimum corrosion amounts required to initiate new cracks by Morinaga's method in consideration of corrosion amounts to fill up voids around reinforcements. We analyze the deterioration processes of building groups by using three scenarios with several histories of preferences of building owners based on ISO 19208. It is confirmed that the averages of acceleration-period arrival rates in the group vary in line with the characteristics of each scenario and are lower than the repair limits for each preference and half of the 3% upper-confidence limits. Although this method is embryonic, we quantitatively and theoretically demonstrate the super-long-term combined deterioration processes of the building group.
  • Heongwon Suh, Hyeonseok Jee, Jihoon Kim, Ryoma Kitagaki, Shinobu Ohki, Seungmin Woo, Keunhong Jeong, Sungchul Bae
    CONSTRUCTION AND BUILDING MATERIALS 235 2020年02月 
    This study investigates the effects of rehydration conditions (different hydration durations at 20 degrees C/60% relative humidity (RH) and in water) on the mechanical and atomic structural recovery of cement paste heated to temperatures of 200, 500, 800, and 1000 degrees C. Variations in the mass, bulk density, compressive strength, and surface morphology of the paste due to heating and rehydration were characterized. In addition, variations in the hydration products and the mean chain length (MCL) of calcium silicate hydrates (C-S-H) in the pastes due to heating and rehydration were analyzed using X-ray diffraction and Si-29 solid-state nuclear magnetic resonance spectroscopy (Si-29 NMR), respectively. The compressive strength of the cement paste heated up to 500 degrees C recovered much more when the paste was placed in water while hot and water-rehydrated for 24 h than when it was rehydrated at 20 degrees C/60% RH. This mechanical recovery could be induced by accelerated hydration, which results in the formation and enhanced silicate polymerization of C-S-H. Si-29 NMR analysis further indicated that the mechanical recovery of cement paste was correlated linearly with the increase in the MCL of C-S-H. In contrast, no mechanical recovery was observed in the cement pastes heated at 800 degrees C and 1000 degrees C after rehydration due to the decomposition of C-S-H. (C) 2019 Elsevier Ltd. All rights reserved.
  • Atsuki Tanifuji, Takato Ishida, Ryoma Kitagaki
    Current Topics and Trends on Durability of Building Materials and Components - Proceedings of the 15th International Conference on Durability of Building Materials and Components, DBMC 2020 177 - 182 2020年 
    Polyurethane composite coatings are frequently applied to strengthen the barrier properties of various construction materials such as wood, metal and concrete. The changes of color and glossiness of the composite coatings for building materials proceeds more slowly than that of polyurethane because of containing fillers and several types of additives. However, the most critical barrier properties have not been studied directly based on the difference from the degradation mechanism of polyurethane coatings. Additionally, the difference in thermal and UV degradation mechanisms of coatings is not clear in the existing studies dealing with conventional accelerated weathering tests and outdoor exposure tests. Therefore, the behavior of the filler contained in the coatings was observed using an oven to accelerate thermal degradation. The chemical analysis of the coating surface by XPS and the analysis of the images and elemental mappings by SEM-EDS were carried out, and the mechanism of degradation progress was investigated. In addition, the temperature dependency of the degradation was studied in changing the heating temperature. It was suggested that polymer and fillers interact in promoting mass transfer at the same time as the thermal degradation reaction consequently.
  • T. Ishida, R. Kitagaki, H. Hagihara, Y. Elakneswaran
    XV International Conference on Durability of Building Materials and Components. eBook of Proceedings 1023 - 1030 2020年 
    Multi-scale analysis of photodegradation are conducted for pigmented coating containing acrylic urethane + TiO2pigment and for non-pigmented coating containing only acrylic urethane. We discuss the intrinsic differences in the photodegradation mechanism between the pigmented and nonpigmented coatings and the effect of the interface between the pigment and the binder. Photo-aging tests are conducted using artificial ultraviolet (UV) irradiation under conditions of 60 °C and dry atmosphere. The results of Fourier transform infrared spectroscopy (FTIR), solvent swelling experiments, ultrasonic measurements of elastic moduli, and colourimetry used for material characterisation before and after photo-aging. Although the behaviour of E and the carbonyl index (CI) show common trends for both samples, the overall trends of yellowness index (YI) and swelling degree (Q) differ significantly between the pigmented and non-pigmented samples. The results reveal that changes in macroscopic properties may not necessarily correspond with the CI behaviour and that characteristic interfacial effects exist between the pigment and the binder. The onsets of coating erosion and chalking are observed in the pigmented coating as surface topological changes. The different behaviour of YI and Q between the sample types can be attributed to the interfacial effect at pigment/binder interface based on the photocatalytic effect from TiO2pigment.
  • Nguyen Xuan Tung, Ryoma Kitagaki, Yoshiro Yamakita
    Innovation for Sustainable Infrastructure 54 477 - 482 2020年 
    There are many damage types on concrete structures. Crack and spalling on concrete structures are the most popular damages. The causes of these damage are variable but mostly originate from the corrosion of reinforcement that cause by the salty, humidity air, carbonation or ion chloride penetration via appeared cracks on the concrete surfaces that lead to the expansion of the reinforcement cross section. It is necessary to protect the surface area of concrete in order to prevent concrete structures from being deteriorated. The method of applying a surface protective agent has been developed as one of the methods to protect concrete. In this study, the repairing effects of lithium silicate based surface protective agent in high permeability and chloride resistance will be evaluate. As a result, reduction of coefficient of water permeability and effective diffusion coefficient of chloride ion of hardened concrete that had been repaired by the lithium silicate based surface protective agent were confirmed.
  • 石田 崇人, 北垣 亮馬, 萩原 英昭
    塗装工学 = Journal of Japan Coating Technology Association 55 12 488 - 495 日本塗装技術協会 2020年
  • Takato Ishida, Ryoma Kitagaki, Hideaki Hagihara, Yogarajah Elakneswaran
    POLYMER 186 2020年01月 
    Structural changes induced by photo-aging have significant influence on material properties. The prediction of the period prior to the onset of significant morphological changes is useful in determining material service lifetime. We assume "degelation" to be the starting point of significant morphological change during photo-aging. Herein, we demonstrated the relationship between such time and the "degelation" phenomenon for an acrylic-urethane network polymer. We also derived a "degelation" theory considering network imperfections, e. g. dangling chains and looping chains. This provides a more accurate representation of reactive curing polymers widely used in industries. Lastly, we estimated the "imperfection degree" by comparing the number of elastically active chains obtained from a swelling experiment with the theoretically derived number. In this system, samples may originally possess approximately 10% network imperfection and it influences on the degelation period in aging process. Our study may potentially contribute to a more accurate prediction of the onset of significant structural change.
  • A new concrete frost resistance evaluating method considering moisture content increase under outdoor exposure
    Dequn Ma, Osamu Senbu, Ryoma Kitagaki
    Journal of Asian Concrete Federation 5 2 20 - 26 2019年12月
  • 米谷怜, 千歩修, 北垣亮馬, 根本かおり
    コンクリート年次論文集 1137 2019年07月
  • The effect of lowest temperature in the accelerated freeze-thaw test on concrete frost deterioration
    Ma D, Kitagaki R, Senbu O
    Proceedings of the Japan Concrete Institute 1140 2019年07月
  • Takato Ishida, Ryoma Kitagaki, Shogo Yamane, Hideaki Hagihara
    POLYMER DEGRADATION AND STABILITY 162 85 - 93 2019年04月 
    The structural alteration of acrylic-urethane coatings, induced by photo-aging, and its temperature dependence, was investigated using positron annihilation lifetime spectroscopy and solvent swelling experiments. The results revealed a slight structural alteration due to photo-aging at 20 degrees C. On the other hand, a significant structural alteration occurred due to photo-aging at 60 degrees C, which resulted in a decrease in the pore size and total pore volume. To study the mechanism of such morphological changes, infrared spectra were measured before and after aging the samples. The results revealed the breakage of the urethane crosslink points and the generation of various photo-products including peroxide species that can form hydrogen bonds. This indicates the foundation of new physical and chemical crosslinks (different from the initial urethane linkage). Based on the chemical modifications, probable mechanisms of the internal morphological changes are proposed. Moreover, the changes are mainly due to an enhancement in the chain-mobility, due to the destruction of the polymer network and an increase in the inter-chain interactions. The results of this study reveal that significant internal structural alterations can occur after sufficient damage to the initial network structure. The proposed explanation is reasonable in relation to the temperature dependence of photo-induced structural alterations, and with respect to the molecular mobility and reaction ratio of photo-oxidation. (C) 2019 Elsevier Ltd. All rights reserved.
  • 三好徹志, 北垣亮馬, 野口貴文
    日本建築学会構造系論文集 84 755 1 - 8 2019年01月 
    Corrosion process of reinforcements of RC building group based on super long-term combined deterioration is integrated into the seismic assessment and changes of human and building damage in virtual earthquakes causing one fatality at the new condition are analyzed. The number of fatalities in the group with maintenance and deterioration by the scenario oriented for Economy does not change for 200 years, but maintenance could not eradicate the increase of severely injured people and completely collapsed buildings. Risk of buildings in super long-term should be reviewed for the group unit stochastically because of the uncertainty of seismic performance.
  • Yuan Lin, Shimpei Nomura, Yoichi Ikemoto, Yuki Obuchi, Xueting Wang, Toshihiko Yamasaki, Ryoma Kitagaki, Satoshi Toriumi, Mikihisa Hayashi, Ai Sakai, Nobuhito Haga
    IEEE 8th Global Conference on Consumer Electronics(GCCE) 447 - 448 2019年 
    We have been developing IoT sensor systems for real estate evaluation. In this paper we propose a method to measure thermal diffusivity to evaluate real estate properties. With our IoT sensor system, we have measured multiple environmental data in 109 apartments across Japan. It has been revealed that the thermal diffusivity performance can vary depending on quality, material, and age of the apartments.
  • The repairing effects of lithium silicate based material to the surface of hardened concrete
    Nguyen Xuan Tung, Ryoma Kitagaki, Yoshiro Yamakita
    Congrès International de Géotechnique - Ouvrages – Structures 2019年
  • 師橋憲貴, 日野優輝, 北垣亮馬, 小川敦久
    日本建築学会構造系論文集 83 751 1319 - 1329 2018年09月 
    The Architectural Institute of Japan (AIJ) published a Recommendation for Mix Design, Production and Construction Practice of Concrete with Recycled Concrete Aggregate. Based on the Recommendation, recycled aggregate concrete using a mixture of low quality recycled aggregate was applied to reinforced concrete beams. As a result, a series of beam specimens using a mixture of low quality recycled fine aggregate and normal fine aggregate that included recycled coarse aggregate at a low substitution rate showed a tendency of having less drying shrinkage cracks. No significant differences of the bond splitting strength existed between normal concrete and that recycled aggregate concrete.
  • 三好 徹志, 北垣 亮馬, 野口 貴文
    日本建築学会構造系論文集 83 749 953 - 961 日本建築学会 2018年07月 
    In this paper, cracks of concrete proceeded from corrosion of reinforcements are analyzed as indices of super long-term combined deterioration processes of RC building groups with finishing materials, pre-induced cracks and maintenance.
    Specifications for finishing materials are systemized by permeability, deterioration mechanism, deterioration speed and demeanor after repairs and Agent Base Modelling is adopted about decision-making for building specifications.
    It is clarified that the average acceleration period arrival rates vary in line with the characteristics of each scenario and are less than repair limits for the group and are one second of 3％ upper confidence limits.
  • RETech@ICMR 2018年
  • 北垣亮馬, 石田崇人, 長根乃愛, 片桐由希子
    日本建築学会大会学術講演会，オーガナイズドセッションG 空間社会形成への取組みと課題 2018 2018年
  • 石田 崇人, 北垣 亮馬
    塗装工学 = Journal of Japan Coating Technology Association 53 4 114 - 121 日本塗装技術協会 2018年
  • 石田 崇人, 北垣 亮馬
    高分子論文集 75 3 265 - 274 公益社団法人 高分子学会 2018年 
    建築材料用ウレタン塗膜を低湿度環境で試料表面温度を変化させた環境で紫外線照射試験を行い，暴露による化学結合変化をFT-IR，ラマン分光で，弾性係数変化を超音波パルス法で測定し，それらの光劣化メカニズムについて議論した．この系では共役二重結合連鎖が有効に形成されず，黄変は目視で確認できなかったが，黄変につながる物質の変性が生じていることがラマン分光法の結果から示唆された．また，著名な劣化反応のNorrish反応は温度依存，光-Fries反応は温度非依存の傾向を示した．さらに，暴露による凝集状態変化に関与する指標(メチレン基とメチル基の吸光度比)を抽出し，弾性係数変化との関連を議論した結果，暴露初期においてはその指標である程度弾性係数の変化を説明できるが，暴露が十分進んだ系においては指標のみで弾性係数変化を議論することは困難であった．
  • 北垣 亮馬
    高分子論文集 75 4 347 - 357 公益社団法人 高分子学会 2018年 
    近年の建築物の長寿命化需要の高まりに伴い，建築用塗膜のバリア性能の評価が重要になりつつあるが，一般的な高分子膜と同様の性能評価試験の適用が困難なため，どのようなガス種類に対してどれほどのバリア性を有するのか，塗膜単味を対象とした評価手法が構築されてこなかった経緯がある．そこで本研究では，建築用塗膜を中心とする高分子膜において，気体の物質移動抵抗性の評価が可能な測定手法の一つとして，昇温脱離法分析装置を用いた気体透過・拡散・溶解度係数の測定について検討を行った．その結果，昇温脱離法分析装置に標準サンプルを供した試験によって，気体透過・拡散係数の測定が可能であることが示された．さらに，本研究で用いた建築用塗膜においては，ガラス状態とみなして物質移動抵抗性を評価することが望ましく，実験結果により，温湿度環境と材料の組合せによって，物質移動の特性が異なること，複数種類気体が透過，拡散する場合は相互作用があることが示された．そして，これらの結果は，一般的な高分子においてもこれまでに指摘されてきたように，建築用塗膜中の気体分子の移動現象についても自由体積の影響を示唆するものである可能性が指摘された．
  • 歴史文化資源のためのデータベースの構築と地域利活用を考慮した価値構造の自動評価手法に関する研究
    北垣亮馬, 林 憲吾, 谷川竜一, 鮎川 慧, 三村 豊, 村松 伸
    第40回情報･システム･利用･技術シンポジウム R21 2017年11月
  • マルチエージェント人工市場への行動経済学的手法の導入による建設資材の市場価格変動の再現に関する研究
    北垣亮馬, 三好徹志
    第40回情報･システム･利用･技術シンポジウム R02 2017年11月
  • 木戸 聡, 石田 崇人, 北垣 亮馬
    情報システム技術 2017 2017 91 - 92 日本建築学会 2017年07月20日
  • 工藤高弘, 北垣亮馬
    日本コンクリート工学会年次論文集 39 2017年07月
  • 久永 真子, 北垣 亮馬, 金 志訓
    日本コンクリート工学会年次論文集 39 2017年07月
  • 三好 徹志, 北垣 亮馬, 野口 貴文
    社会技術研究論文集 : Sociotechnica 14 146 - 155 社会技術研究会 2017年06月
  • 鉄筋コンクリートの超長期複合劣化過程の反応型非定常拡散方程式による解析的考察 超長期複合劣化による建築物群のリスクの確率論的考察 その1
    三好徹志, 北垣亮馬, 野口貴文
    日本建築学会構造系論文集 82 2017年
  • 金 志訓, 北垣亮馬
    日本コンクリート工学会年次論文集 39 1 2017年
  • 北垣 亮馬
    精密工学会誌 83 7 647 - 650 公益社団法人 精密工学会 2017年
  • 三好 徹志, 北垣 亮馬, 野口 貴文
    日本建築学会構造系論文集 82 735 625 - 632 日本建築学会 2017年 
    In this study, combined deterioration mechanism in reinforced concrete with CO2, flying salt, acid rain is reconstituted by transient reaction-diffusion equation and super long-term deterioration process is analyzed in RCP scenario.
    This method is confirmed to be consistent with research of the past about carbonation and to be suitable for complex hysteresis in RCP scenario.
    Simple formula for building group is also formed and reliability design method with mixture distribution of carbonation in several RCP scenarios is proposed. Probability of carbonation by mixture distribution increases in durable member with thick cover depth after 100 years.
  • Gaochuang Cai, Takafumi Noguchi, Herve Degee, Jun Zhao, Ryoma Kitagaki
    ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH 23 8 7220 - 7243 2016年04月 
    Massive volcano-related materials (VRMs) erupted from volcanoes bring the impacts to natural environment and humanity health worldwide, which include generally volcanic ash (VA), volcanic pumice (VP), volcanic tuff (VT), etc. Considering the pozzolanic activities and mechanical characters of these materials, civil engineers propose to use them in low carbon/cement and environment-friendly concrete industries as supplementary cementitious materials (SCMs) or artificial/natural aggregates. The utilization of VRMs in concretes has attracted increasing and pressing attentions from research community. Through a literature review, this paper presents comprehensively the properties of VRMs and VRM concretes (VRMCs), including the physical and chemical properties of raw VRMs and VRMCs, and the fresh, microstructural and mechanical properties of VRMCs. Besides, considering environmental impacts and the development of long-term properties, the durability and stability properties of VRMCs also are summarized in this paper. The former focuses on the resistance properties of VRMCs when subjected to aggressive environmental impacts such as chloride, sulfate, seawater, and freezing-thawing. The latter mainly includes the fatigue, creep, heat-insulating, and expansion properties of VRMCs. This study will be helpful to promote the sustainability in concrete industries, protect natural environment, and reduce the impacts of volcano disaster. Based on this review, some main conclusions are discussed and important recommendations regarding future research on the application of VRMs in concrete industries are provided.
  • Heesup Choi, Hyeonggil Choi, Myungkwan Lim, Masumi Inoue, Ryoma Kitagaki, Takafumi Noguchi
    INTERNATIONAL JOURNAL OF CONCRETE STRUCTURES AND MATERIALS 10 1 87 - 97 2016年03月 
    In this study, a quantitative review was performed on the mechanical performance, permeation resistance of concrete, and durability of surface-modified coarse aggregates (SMCA) produced using low-quality recycled coarse aggregates, the surface of which was modified using a fine inorganic powder. The shear bond strength was first measured experimentally and the interface between the SMCA and the cement matrix was observed with field-emission scanning electron microscopy. The results showed that a reinforcement of the interfacial transition zone (ITZ), a weak part of the concrete, by coating the surface of the original coarse aggregate with surface-modification material, can help suppress the occurrence of microcracks and improve the mechanical performance of the aggregate. Also, the use of low-quality recycled coarse aggregates, the surfaces of which were modified using inorganic materials, resulted in improved strength, permeability, and durability of concrete. These results are thought to be due to the enhanced adhesion between the recycled coarse aggregates and the cement matrix, which resulted from the improved ITZ in the interface between a coarse aggregate and the cement matrix.
  • The Chemical Changes Of Cement Paste With Silicate-Based Surface Penetrants
    Jihoon Kim, Ryoma Kitagaki
    the 7th international conference of Asian concrete federation 2016年
  • 長田美咲, 北垣亮馬
    日本熱物性学会シンポジウム B322 2016年
  • 母集団の多重共線性を考慮したヘドニック・アプローチによる集合住宅における中古・賃貸市場の価格形成因子の定量的評価に関する研究
    北垣亮馬, 米沢裕人
    国立情報学研究所，IDRユーザフォーラム 2016年
  • 金 志訓, 北垣 亮馬, 木戸 聡
    コンクリート工学年次論文集 38 1 1911 - 1916 日本コンクリート工学会 2016年 
    コンクリート表面に新しい水和物を生成させ緻密化させる補修技術として利用される、ケイ酸ナトリウム表面含浸材の補修効果をセメント硬化体中のCa(OH)2量に基づき、投入する水ガラスの比率を変えて検討した。Ca2+と水ガラスから生成される新しいC-S-Hを含むセメント硬化体の化学的変化をXRD及びMAS NMRを用いて検討し、Ca/Si比が高い試験体がC-S-H及び元のC-S-Hにおいて、SiとAlの置換が起こっている可能性が示唆され、C-A-S-Hに近い構造が現れることを確認した。
  • Takafumi Noguchi, Won-Jun Park, Ryoma Kitagaki
    RESOURCES CONSERVATION AND RECYCLING 104 405 - 416 2015年11月 
    Recycled aggregate (RA) obtained from demolished concrete waste (CW) is beneficial owing to its applicability in recycled aggregate concrete (RAC). However, in designing RAC mix proportions, various impurities in the RA that can adversely affect the properties of the concrete, should be considered. Current RA production focuses on the physical quality of the RA without consideration of the impurities present. To improve the stable production and use of RAC, the amounts of deleterious impurities present and their effects on the concrete mix should be estimated. In this study, the risk associated with the presence of impurities in RA was defined as including the amount of impurity residue in the RA and the effects of impurities on RAC properties Both impurity types and RA production methods were considered in assessing risk for five building demolition scenarios. To quantify the risk, the amount of demolished building waste was estimated, the amount of CW was predicted, the RA ratio was calculated from the predicted amount of ON, and impurity sorting levels were investigated for nine methods of RA production. The impurity residue ratio per unit RA was estimated for each demolition scenario, RA production method, and RA quality level considered. A risk model is proposed in this paper that can be used to estimate the risk of RA adversely affecting RAC performance using information on the demolition scenario and the RA production method. (C) 2015 Elsevier B.V. All rights reserved.
  • Utilization of CO2 Nanosized Bubble for Improving Quality of Recycled Concrete Aggregate
    Takafumi Noguchi, Ryoma Kitagaki, Han-sic Kim
    Thirteenth International Conference on Recent Advances in Concrete Technology and Sustainability Issues 2015年07月
  • Hyeonggil Choi, Myungkwan Lim, Ryoma Kitagaki, Takafumi Noguchi, Gyuyong Kim
    CONSTRUCTION AND BUILDING MATERIALS 84 468 - 476 2015年06月 
    The purpose of this study was to qualitatively assess the shrinkage reduction and cracking restraint of expansive additives under various restraint conditions. The reduction of drying and autogenous shrinkages on the addition of expansive additives was confirmed. The results of a ring test performed to determine restrained shrinkage indicated that at the same age, the cracking potential of expansive mortar based on the stress/strength ratio remained lower than that of normal mortar, which confirmed that the generation of compressive stress at an early age reduced the restrained stress and restrained cracking. From the time that cracking occurred, the expansive mortar showed substantial stress relaxation, reducing the tensile stress caused by the interface restraint load. Moreover, the use of expansive additives could reduce the degree of restraint under the same restraint condition, preventing the occurrence of cracking due to shrinkage. (c) 2015 Elsevier Ltd. All rights reserved.
  • Jaecheol Ahn, Takafumi Noguchi, Ryoma Kitagaki
    MATERIALS 8 5 2433 - 2453 2015年05月 
    Efficient maintenance and upgrading of a building during its lifecycle are difficult because a cementitious finish uses materials and parts with low disassembly properties. Additionally, the reuse and recycling processes during building demolition also present numerous problems from the perspective of environmental technology. In this study, an induction heating (IH) method was used to disassemble cementitious finish joints, which are widely used to join building members and materials. The IH rapidly and selectively heated and weakened these joints. The temperature elevation characteristics of the cementitious joint materials were measured as a function of several resistor types, including wire meshes and punching metals, which are usually used for cementitious finishing. The disassembly properties were evaluated through various tests using conductive resistors in cementitious joints such as mortar. When steel fiber, punching metal, and wire mesh were used as conductive resistors, the cementitious modifiers could be weakened within 30 s. Cementitious joints with conductive resistors also showed complete disassembly with little residual bond strength.
  • 彌永宏之, 長田美咲, 北垣亮馬
    日本熱物性学会シンポジウム D131 2015年
  • 長田美咲, 彌永宏之, 北垣亮馬
    日本熱物性学会シンポジウム D132 2015年
  • 米村 美紀, 北垣 亮馬, 大窪 貴洋, 金 志訓
    コンクリート工学年次論文集 = Proceedings of the Japan Concrete Institute 37 1 511 - 516 日本コンクリート工学会 2015年 
    ホワイトセメントを用いたセメント硬化体の細孔構造分析について， 1Hの横緩和時間分布の測定結果からHalperinらの方法を用いてゲル細孔領域に限定した空隙分布推定を行った。DSCサーモポロメトリーでの結果と比較することでその可能性について検討し，ピークの位置や形状について概ね整合性が確認された。サーモポロメトリーの分解能は2nm以上であるが，NMRはそれより小さい細孔に対しても有効である可能性があり，また短時間で測定できるという利点もある。ただし，今回はごく限られた条件の試料による結果にとどまるため，今後の精度の向上，定量化の手法については検討が必要である。
  • 金 志訓, 北垣 亮馬, 割田 聖洋
    コンクリート工学年次論文集 37 1 1543 - 1548 日本コンクリート工学会 2015年 
    コンクリート表面を炭酸化によって緻密化させる方法として，CO2ナノバブルを含む溶液を繰返し浸漬させる効果をW/Cの異なるモルタルごとに測定した。炭酸化による空隙充填効果を重量変化及び吸水率から検討し，W/Cが高い試験体ほどCO2ナノバブル水溶液による空隙充填効果が高い結果を確認した。また，生成した炭酸カルシウムが閉気孔を生成し空隙を閉塞させる効果をW/Cごとに検討し，W/Cが高いほど閉塞効果が高いことが確認された。
  • Hyeonggil Choi, Heesup Choi, Myungkwan Lim, Takafumi Noguchi, Ryoma Kitagaki
    CONSTRUCTION AND BUILDING MATERIALS 75 266 - 274 2015年01月 
    This study modeled volume changes of concrete mixed with expansive additives, a countermeasure to shrinkage. Volume changes of expansive paste are determined from the balance between the shrinkage of cement and the expansion of the additives. Therefore, in this study, volume changes were modeled by applying a balance to the hydrates of cement and the expansive additives. The shrinkage of cement was modeled by assuming that it is caused by capillary tension. This modeling was based on the behavior of the moisture inside the cement's pore structure, by taking into account the pore size distribution and the thermodynamic equilibrium state of the moisture. Using the concept of effective radius factor, the expansion of the expansive additives was modeled by considering the volume expansion of the additive particles caused by an increase in the outermost radius of particles of the hydration products that were formed at an early age. The values predicted by the model were consistent with the measured values, which confirms the model's validity. Furthermore, the volume changes of concrete were estimated with sufficient accuracy by analyzing the behavior of the paste using a composite model of aggregate and paste. (C) 2014 Elsevier Ltd. All rights reserved.
  • Hyeonggil Choi, Myungkwan Lim, Heesup Choi, Takafumi Noguchi, Ryoma Kitagaki
    MAGAZINE OF CONCRETE RESEARCH 67 7 335 - 348 2015年 
    The creep phenomenon of hardened cement mixed with expansive additives (EAs) was modelled by considering the creep performance of hydration products of cements and EAs under the assumption that the characteristics of hydration products of cements and EAs are fixed. A new composite model that is appropriate for particle conditions is proposed by considering the balance of the hydration products of cement and EA and the stress redistribution phenomenon of hydration products newly generated by the progress of hydration. Verification of the creep model indicated that the accumulated creep strains calculated by the model and those obtained through experiment were similar, thereby confirming that the model shows excellent estimation and evaluation performance. Furthermore, the stress could be sufficiently estimated by analysing the creep phenomenon corresponding to the progress of hydration under the restrained condition.
  • Da-Young Oh, Takafumi Noguchi, Ryoma Kitagaki, Won-Jun Park
    RENEWABLE & SUSTAINABLE ENERGY REVIEWS 38 796 - 810 2014年10月 
    CO2 emitted from calcination processes in kilns comprises 60% of all emissions from cement production. The chemical components of building materials, demolished inorganic building materials (DIBMs), and waste concrete powder (WCP) are similar to those of cement minerals. Therefore, if DIBMs are used as a cement substitute material along with limestone, the quantity of disposed waste and the use of limestone will likely be reduced, as will CO2 emissions during cement production. This study proposes a recycling method for recycled cement, using DIBMs and WCP as cement substitute materials, and the properties of trial recycled cement were evaluated. The mortar specimen using recycled cement showed a high compressive strength, as did the ordinary Portland cement mortar. According to the proposed composition, the producible recycled cement was derived from 0.5% to 9.1% of annual cement production (about 57.6 million tons) in Japan. Additionally, the CO2 reduction by usage of recycled cement ranged from 0.06 million tons to 0.72 million tons from the total annual CO2 emissions from cement production (about 29.4 million tons), using natural resources in Japan. (C) 2014 Elsevier Ltd. All rights reserved.
  • Heesup Choi, Ryoma Kitagaki, Takahumi Noguchi
    JOURNAL OF ADVANCED CONCRETE TECHNOLOGY 12 2 34 - 45 2014年02月 
    In this study, Author present a quantitative review of the mechanical performance, as well as the separation from the matrix and the recovery performance of surface modification coarse aggregate (SMCA) that was produced using aggregate, whose surface was modified using fine inorganic powder. Therefore, experiments were conducted to measure the compressive strength, microwave heating characteristics, distribution of the void volume, and chemical changes in SMCA concrete, as well as the recovery rate of the aggregate. The results of the experiments showed that reinforcing the interfacial transition zone, which is a weak part in concrete, by coating the surface of the original coarse aggregate with cement paste, can help suppress the occurrence of microcracks and improve the mechanical performance of the aggregate. Further, microcracking and the decomposition of hydrates were observed as a result of microwave heating. In other words, an increase in void size distribution and weakening of the hydrated cement paste led to the effective recovery of recycled coarse aggregate.
  • Creep behavior of expansive concrete
    Hyeonggil CHOI, Myungkwan LIM, Takafumi NOGUCHI, Ryoma KITAGAKI
    Proceedings of ICMMA 2014 (The 8th international conference on multi-functinal materials and applications), 273 - 277 2014年
  • Development of Eco-Friendly Deconstruction Technologies for Recycling Construction Waste
    Myungkwan Lim, Heesup Choi, Hyeonggil Choi, Ryoma Kitagaki, Takahumi Noguchi
    Journal of Environmental Protection 5 7 2014年
  • Using Microwave Heating to Completely Recycle Concrete
    Heesup Choi, Myungkwan Lim, Hyeonggil Choi, Ryoma Kitagaki, Takahumi Noguchi
    Journal of Environmental Protection 5 7 2014年
  • 相 尚寿, 北垣 亮馬, 片桐 由希子, 田村 順子
    GIS-理論と応用 22 1 27 - 35 一般社団法人 地理情報システム学会 2014年 

    This paper proposes a cost estimation sheet supporting decision making for city planning. The urban form is represented by 30 by 30 cells on the sheet and the cost is estimated regarding population distribution, population projection, maintenance cost of road network, water supply and sewerage network, and investment for new development site. The sheet first requests its user to input current population distribution and several cost parameters. Then the sheet designates the downtown cells. A distance from closest downtown cell is calculated for each cell, which is used for cost estimation. User will be asked to finalize the spatial plan where cells are given the following labels; downtown, to be developed as new sub centers, to be disengaged. The maintenance cost is calculated by number of cells, distance from closest downtown, and population within the cell. Finally, the sheet gives how long does it take until the saving of maintenance cost by disengagement will balance the development cost of new sub centers.

  • ロードサイド型コンパクトシティ実現のための試算モデルの構築
    北垣 亮馬
    Sustainable Urban Regeneration, 東京大学 都市持続再生研究センター 31 2013年03月
  • ロードサイド型コンパクトシティ実現のための検討項目・事例２ コンポスト研究
    北垣 亮馬
    Sustainable Urban Regeneration, 東京大学 都市持続再生研究センター 31 2013年03月
  • 熊英, 北垣亮馬, 野口貴文
    コンクリート工学年次論文集 35 1 2013年
  • 崔 亨吉, 辻埜 真人, 野口 貴文, 北垣 亮馬
    セメント・コンクリート論文集 67 1 282 - 289 一般社団法人 セメント協会 2013年 
    コンクリートのひび割れ抑制対策として利用されている膨張材を用いたコンクリートを対象として、その基本特性の把握および実構造物レベルでの膨張材の効果に対して検討を行った。実機プラントを利用して検討した結果、膨張材によるコンクリートの乾燥収縮および自己収縮の低減効果が認められた。一方、膨張材を用いたコンクリートの擬似完全拘束条件下での引張応力強度比は低い値で推移し、膨張材による引張応力の低減効果が確認できた。実構造物の外壁およびスラブにおいても、膨張材を用いることで、初期材齢において膨張に伴う圧縮応力が有効に導入され、コンクリートの引張応力を低減することができた。さらに、長期材齢におけるひび割れを評価した結果、膨張材を用いたコンクリートのひび割れ面積は、普通コンクリートの約35％で、膨張材のひび割れ低減効果が確認できた。
  • Hyungjun Kim, Takafumi Noguchi, Ryoma Kitagaki, Whajung Kim, Woosuk Kim
    7TH ASIAN SYMPOSIUM ON POLYMERS IN CONCRETE 273 - 280 2012年 
    Repair and strengthening are significantly important for long service life of buildings against deteriorating durability, disaster and building fire especially. Polymer-modified cement mortar (PCM) has been extensively used as a high performance material particularly for finishing and repairing works in concrete building because of its excellent adhesion, waterproofing, resistance to chemical attack, and workability. As PCM contains organic polymer, it is necessary to clarify its mechanical properties at high temperature under fire, on which sufficient data are not enough and also not available. This study focused on the compressive strength and elastic modulus of various PCMs containing three types of polymers according to the types of polymer, unit-polymer content and polymer-cement ratio. As a result, PCM with 5% unit polymer content which polymer types are EVA and PAE, showed outstanding compressive strength at 20 similar to 400 degrees C. Modulus of elasticity of PCM showed a decreasing tendency according to unit-polymer content regardless of polymer type at elevated temperature.
  • ENVIRONMENTAL IMPACT MINIMIZATION AND PERFORMANCE MAXIMIZATION IN CONCRETE RECYCLING, Structural Concrete
    Takafumi NOGUCHI, Ryoma KITAGAKI, Masato TSUJINO
    Structural Concrete, fib 11 1 2011年03月
  • Takafumi Noguchi, Ryoma Kitagaki, Masato Tsujino
    STRUCTURAL CONCRETE 12 1 36 - 46 2011年03月 
    The sheer amount of concrete in use and in stock compared with other building materials throws up environmental issues such as the huge amount of CO2 emitted when cement and concrete are produced and transported and the enormous amount of waste generated when concrete is disposed of. In addition, we are beginning to deplete aggregate resources at a fast rate. Concrete has conventionally been regarded as being difficult to recycle. The construction industry has addressed these problems and carried out research and development regarding the recycling of concrete since the 1970s. Recycling technology has been shifting from simple crushing into scrubbing with some preparations to produce high-quality recycled aggregate for structural concrete, and recycling of concrete in a completely closed loop has now become technically feasible. This paper reviews the development history of recycling technologies in Japan from the viewpoint of the properties of recycled aggregate and recycled aggregate concrete as well as the environmental impact such as CO2 emissions and waste generation in recycling. The paper also presents the outline of completely recyclable concrete, with which closed-loop circulation of component materials is realized.
  • 三谷 卓摩, 北垣 亮馬, 長井 宏憲, 野口 貴文
    日本LCA学会誌 7 1 79 - 83 日本LCA学会 2011年 
    Objective. This study proposes a comprehensive method for calculating transporting distance on ecoMA. Moreover, as an example of the method’s application, the study conducted a simulation of material flow that meets the fresh concrete demand in four prefectures of Kanto region and calculated CO2 emissions from the process of production and transportation.
    Results and Discussion. The share of CO2 emissions from transportation was 5.7% for road distance, which was 1.2% higher than when linear distance was used. It was understood that total amount of CO2 emissions from transportation is 1.3 times that of emissions when linear distance was used. Looking at the transportation of crushed stone, sand, cement (cement service station – fresh concrete factory) and cement (cement factory – cement services station), road distance was between 1.30 and 1.43 times greater than linear distance. For transportation of products other than fresh concrete, it was understood CO2 emissions for road transportation are much higher than those for linear transportation. Furthermore, for cement (cement factory – cement service station), the ratios of CO2 emissions for linear distance and road distance were large compared to crushed stone and sand, which are often transported over long distances from the suburbs to urban centers, and therefore it was understood that transportation distance caused by use of road distance depending on material types as well as geographic characteristics.
    Conclusions. By providing an example of ecoMA with a calculation module that can take road distance into account, this study demonstrated that it is possible to calculate CO2 emissions accurately with consideration for road distance. As a result, it has become possible to quantitatively calculate how much larger CO2 emissions are for road distance when compared to linear distance.
  • 辻埜 真人, 野口 貴文, 北垣 亮馬, 長井 宏憲
    日本建築学会構造系論文集 76 660 223 - 229 日本建築学会 2011年 
    To build up a resource recycling society, the environmental issue of concrete is approached comprehensively with a new technique using aggregate coating with dielectric material and microwave heating. The increase of concrete strength is achieved by 1.2 times using improved coating agent mixed properly with silica-fume and by-product powder. The recovery of high-quality aggregate can also be achieved with low energy by using microwave heating selectively for coating layer. In addition, about 90% of original aggregate can be recycled. Thus, the trade-off relationship between “strength of concrete” and “recovery of aggregates” and another trade-off between “energy consumption” and “aggregate quality” have been solved simultaneously.
  • Sectioral & spatial analysis of co2 emission in concrete industry using resource recycling simulator “ecoma” implementing actual road network
    Takuma Mitani, Ryoma Kitagaki, Hironori Nagai, Takafumi Noguchi
    International Conference on Sustainable Urbanization 2010年12月
  • Behavior of sectoral CO2 emission in concrete industry at the case of replacing ready-mixed concrete demands to pre cast concrete products
    Ryoma Kitagaki, Takuma Mitani, Hironori Nagai, Takafumi Noguchi
    International Conference on Sustainable Urbanization 2010年12月
  • Equilibrium point of CO2 emission and material reusability in concrete industry at the case of replacing ready-mixed concrete demands to pre cast concrete products
    Ryoma Kitagaki, Takuma Mitani, Hironori Nagai, Takafumi Noguchi
    2nd International Conference on Waste Engineering and Management 2010年10月
  • Completely Recyclable Concrete of Aggregate-recovery Type by Using Microwave Heating
    Ryoma Kitagaki, Masato Tsujino, Hironori Nagai, Takafumi Noguchi
    the 11th international conference on advance in concrete technology and sustainable development 2010年05月
  • Strategy to reduce CO2 in concrete industry, Green City Group
    Ryoma KITAGAKI
    the 1st Korea-China-Japan Young Researchers Workshop 2010年05月
  • Development of Eco-Friendly Building Material by Densification of Powders through Carbonation and Hydration after Pressure Forming
    Tokihiko Fukao, Ryoma Kitagaki, Hironori Nagai, Takafumi Noguchi
    International Conference on Sustainable Building Asia, Ansan, Korea 2010年02月
  • 辻埜 真人, 野口 貴文, 北垣 亮馬, 長井 宏憲
    日本建築学会構造系論文集 75 647 17 - 24 日本建築学会 2010年 
    To build up a recyclable society, the environmental issue of concrete is approached comprehensively with a new technique using aggregate coating. The increase of concrete strength is achieved by 1.2 times using improved coating agent mixed properly with silica-fume and by-product powder. A similar effect is also affirmed even if applied to low-quality aggregate. A recycling performance shows that over 90% of aggregate can be recycled. In conclusion, the technique developed by this study is effective for the use of low-quality aggregate and the recycle of coarse aggregate as well as the solution of the environmental problem of concrete.
  • 岩田 彩子, 兼松 学, 野口 貴文, 長井 宏憲, 北垣 亮馬, 藤本 郷史
    日本建築学会技術報告集 16 32 43 - 48 日本建築学会 2010年 
    In this research, the carbon dioxide emission intensity of concrete-related industry is investigated based on field survey and discussions are made on influences of plant scale and regional characteristics. As a result, it is shown that the carbon dioxide emission intensity decreases with increase in the volume of annual production, because of the influence of productivity efficiency, and it varies widely at lower volume of annual production. And also the carbon dioxide emission intensity varies by the region depending on the distribution characteristic of plant scale, so that the carbon dioxide emission intensity in Hokkaido, where its productions are relatively-small, is higher than that in Tokyo metropolitan area.
  • Takafuno Noguchi, Ryoma Kitagaki
    2ND INTERNATIONAL CONFERENCE ON WASTE ENGINEERING MANAGEMENT, ICWEM 2010 73 60 - + 2010年 
    The sheer amount of concrete in use and in stock compared with other building materials brings up the environmental issues such as the large amount of CO2 emitted when cement and concrete are produced and transported and the enormous amount of waste generated when concrete is disposed of Besides, aggregate resources are beginning to be depleted at a high speed Concrete has conventionally been regarded as being difficult to recycle The construction Industry has earned out research and development regarding the recycling of concrete since the 1970s in Japan In these days recycling technology has been shifting from simple crushing into scrubbing with some preparations to produce high-quality recycled aggregate for structural concrete The paper reviews the development history of recycling technologies in Japan from the viewpoint of the properties of recycled aggregate and recycled aggregate concrete as well as the environmental impact such as CO2 emission and waste generation in recycling The paper also presents a new technology for enhancing the properties of low quality recycled aggregate for structural use, and is concluded with a proposal toward closed loop resource recycling in concrete industry
  • Hideki Yamagishi, Takuma Mitani, Ryoma Kitagaki, Hironori Nagai, Takafumi Noguchi
    2ND INTERNATIONAL CONFERENCE ON WASTE ENGINEERING MANAGEMENT, ICWEM 2010 73 205 - + 2010年 
    In recent years reduction target of CO2 emission is declared in many countries CO2 emission and industrial waste are controversial issues in concrete related industries because of large amount emission Conventional admixtures of concrete, such as furnace blast slag and fly ash, are by-products from the industries other than concrete industries which significantly motivate to utilize for the low responsibility to their embodied CO2 emission as well as high contribution to improving mechanical properties of concrete in reducing cement consumption, However many researchers have mentioned the difficulties to evaluate quantitative effects for reducing CO2 emission using admixtures because of including CO2 emission in transportation In this paper, reduction of CO2 emission introducing admixtures in large quantity at Kanto region in Japan is quantitatively evaluated using ecoMA a kind of resource flow simulator As a simulation result of ecoma, it was quantitatively observed that CO2 emission is restrained through the replacement of admixture At the case of furnace blast slag and fly ash 3 million tons, and 0 55 million tons of CO2 are cut down respectively
  • 竹田真梨子, 北垣亮馬, 堺孝司
    コンクリート工学年次論文報告集 31 1 1903 - 1908 2009年
  • マルチエージェントシステムを応用した資源循環シミュレーション手法によるコンクリート関連廃棄物の動向予測
    藤本郷史, 北垣亮馬, 兼松学, 野口貴文, 間宮尚, 鈴木宏一
    日本LCA学会誌 2 222 - 228 2006年
  • 北垣 亮馬, 兼松 学, 野口 貴文
    日本建築学会環境系論文集 70 595 141 - 148 日本建築学会 2005年 
    A comprehensive model for wood flows in Japan based on the statistics points out inefficiency that a lot of domestic thinned woods are disposed in spite of the consumption of non-cyclic forest resources from foreign countries for domestic use. Moreover, the model explains that various recycled products made of woodchip would cause decay of flexibility receiving secondary woodchip into the flow. Therefore, new methodologies are required to assess building materials supporting flexibilities of material flows for a dynamic sustainable society as well as existing methods of environmental assessment such as CO2, wastes, and resource consumptions. In existing researches the concept of "a sustainable society" has usually represented "a static society", but a society dreaming of "much more sustainable society" is not necessarily static forever even if material flows look sustainable. In this paper, Aptitude items for a dynamic sustainable society are designed and their effectiveness has been confirmed for assessing wood materials to satisfy these requirements.
  • 北垣 亮馬, 兼松 学, 野口 貴文
    日本建築学会構造系論文集 70 597 33 - 38 日本建築学会 2005年 
    Requirement of long-term use of existing buildings has been increasing in aspect of environmental and economical issues, and the visual impression of building materials from the view point of aesthetics is considered as an important factor for long-term use of buildings. In this research, the new methodology by using 2dimensional Fourier Transformation has been developed for evaluation of stains on exposed concrete surfaces. As a result, various shapes of stains on the constant distance have been explained by the slope of power spectra by frequencies which make up a digital image including stains.
  • 北垣 亮馬, 兼松 学, 野口 貴文
    日本建築学会構造系論文集 70 597 39 - 45 日本建築学会 2005年 
    Requirement of long-term use of existing buildings has been increasing in aspect of environmental and economical issues, and the visual impression from the view of building materials is considered as an important factor for long-term use of buildings. In this research, new methodology by using 2dimensional Fourier Transform is developed for evaluation of visual changes on exposed concrete finishing. As a result, mechanism of phenomena that the view of building materials changes depending on the observation distance could be explained by frequencies comprehensively.
  • 兼松 学, 北垣 亮馬, 野口 貴文, 友澤 史紀
    コンクリート工学年次論文報告集 22 1 211 - 216 日本コンクリート工学協会 2000年06月01日 
    コンクリートの汚染、ひび割れ、表面劣化などの汚れの定量的評価手法の開発を目的として、実構造物のコンクリート壁面、躯体を対象として、CCDカメラから入力したデジタル画像の定量的評価に関する研究を行った。新しい手法である2次元フーリエ変換により得られたPSP画像の特性から、コンクリート表面の状態や汚れなどの評価ができることを確認し、基礎的知見を得た。

講演・口頭発表等

その他活動・業績

受賞

  • 2017年 国立情報学研究所 IDRユーザーフォーラム 最優秀賞
  • 2016年 日本建築仕上学会 技術開発賞
  • 2010年 日本建築仕上学会 論文奨励賞
  • 2010年 SB2010 Seoul Award of Excellency in Research
  • 2007年 SB2007 Seoul Award of Excellency in Research

共同研究・競争的資金等の研究課題

  • 日本学術振興会：科学研究費助成事業
    研究期間 : 2021年07月 -2024年03月 
    代表者 : 川野 潤, 豊福 高志, 北垣 亮馬, 川西 咲子, 荒木 優希
     
    本研究は、研究代表者が近年開発した、反応界面における局所的なpHおよびCaイオン濃度変化を蛍光プローブを用いて可視化する技術を、多様な材料に適用できるように高精度化・汎用化することを目的としている。2022年度においては、以下について研究を進め、成果を得ている。 [1]ゲル内二重拡散法によって合成される炭酸カルシウムについて、形成環境のpHの可視化に成功した。ゲル全体のpH変化を可視化した結果、多形によって形成環境のpHの変化の傾向が異なることが明らかになった。さらにレーザー共焦点顕微鏡を用いた詳細な観察により、カルサイト成長時の結晶近傍のpHに局所的な不均一が生じることを初めて確認した。しかし、アラゴナイト形成場の近傍にはこのような傾向は観察されず、このような形成場の局所的な環境の違いも多形形成に影響を与えている可能性が示唆された。 [2]従来までに観察可能であることが示されている炭酸カルシウム以外の材料についての適用を進めた。特に、リン酸カルシウム系の材料について、溶解時のpH変化およびCaイオン濃度分布の変化を可視化したところ、アパタイトやリン酸八カルシウムなど、物質によって異なる傾向を示すことが観察された。さらに、同じ物質であっても、Naが含有しているものは、含有していないものとは大きく異なるpH変化の傾向を示すことが明らかになった。このことは、生体材料としてリン酸カルシウムを用いたり、生体内でのリン酸カルシウムの形成過程を理解する際の指針となる。
  • 日本学術振興会：科学研究費助成事業 基盤研究(C)
    研究期間 : 2019年04月 -2022年03月 
    代表者 : 北垣 亮馬, 萩原 英昭, 佐藤 浩昭
     
    今年度は予定していた通り，無機ー有機界面を混合物をもちいた薄膜に成型し，それを用いた熱劣化試験を通じて，「化学分析可能・小型・均質な建築材料の試験体作製技術」によって，代表的な建築部材の界面をもつ試験体を作製し，無機ー有機界面にみられる挙動が提案するサンプルにおいてもみられるかの検証を行った． その結果，FT-IRにおいて表面を観察したところ，本研究で提案しているサンプルのほうが，むしろ無機有機界面においてみられる水分の侵入や高分子構造の変化が顕著に見られることが明らかになった． 具体的には，耐候性用に用いられるポリウレタン，接着剤用途に用いられるエポキシ，防水・シーリング用途に用いられる変成シリコーンに，セメント硬化体（粉末化したもの），外装用タイルに用いられるセラミックス（粉末化したもの）を添加し，これをガラス基板にディップコートした上で，同様に作製した無添加の高分子基板とあわせて熱劣化試験，乾湿繰り返し試験を実施した．また，使用した高分子は，純粋な系のものと，市場に出回っているものの両方を利用した． その結果，ポリウレタンはセメント硬化体粉末に対してIRスペクトルにおいてOH基のハローが多くみられた程度であった．また，変成シリコーンはほとんどどの無機粉体に対しても変化がみられなかった．しかし，エポキシ系においては，セメント硬化体粉末を添加した場合に，OH基のハローが大きく変化しただけでなく，付着性能が変化したであろうと考えられる高分子構造の変化がみられた．このことからも，本試験方法において，高分子と無機界面の性能評価や科学的な多様な考察が可能であることが確認された． またそれだけでなく例えば接着剤と被着物の界面の劣化純粋など，高分子物理の観点だけでなく，構造物に適用する場合の性能評価試験としても適用できることもあわせて確認した．
  • 日本学術振興会：科学研究費助成事業 基盤研究(A)
    研究期間 : 2018年04月 -2021年03月 
    代表者 : 野口 貴文, 兼松 学, 北垣 亮馬, 松田 拓
     
    2019年度は、ポルトランドセメントを使用せず、産業副産物・産業廃棄物を改質した粉体、天然未利用資源である非晶質粉体、アルカリ刺激剤を用いて製造される硬化体「カーボンマイナス・リサイクラブル・ハイパフォーマンス・コンクリート」の強度発現に及ぼす①アルカリ刺激剤の濃度、②アルカリ刺激剤の種類（高アルカリ、低アルカリ）、③粉体の化学成分（Ca、Si、Al）の割合、④粉体のガラス化率、⑤粉体の粒度分布、⑥粉体の反応速度などの影響を明らかにするために、モルタルを作製して強度発現試験、熱重量分析、Ｘ線リートベルト法による水和生成物の定量分析、水銀圧入法による細孔空隙量測定など、系統的な実験を行い、Caの割合が多いほど強度が高くなること、セメントコンクリートと同様に圧縮強度は粉体水比に比例すること、初期に高温養生を施すことにより150MPa近い圧縮強度を発現することなどの結果を得た。また、実験結果を基にポルトランドセメントを用いないカーボンマイナス・リサイクラブル・ハイパフォーマンス・コンクリートの調合設計手法に関する検討を行い、結合水量および細孔空隙率を組み合わせた指標を用いることにより、圧縮強度の予測を行えることを見出した。 また、アルカリシリカ反応性骨材を用いた場合において、非晶質粉体が反応抑制効果に及ぼす影響、およびCaイオンの存在がアルカリシリカ反応および膨張に及ぼす影響について、試験体を作製して、Ｘ線回折分析、熱重量分析、細孔構造測定などを行い、ポルトランドセメントを用いないカーボンマイナス・リサイクラブル・ハイパフォーマンス・コンクリートにおけるアルカリシリカ反応は、セメントコンクリートにおけるものとは異なることを明らかにした。 さらに、環境負荷の小さくなるカーボンマイナス・リサイクラブル・ハイパフォーマンス・コンクリートを製造するための材料および調合を提案した。
  • 日本学術振興会：科学研究費助成事業 基盤研究(C)
    研究期間 : 2014年04月 -2017年03月 
    代表者 : 師橋 憲貴, 北垣 亮馬, 小山 潔
     
    本研究は，ビニロン繊維が添加された低品質再生骨材コンクリートを用いた梁部材の付着割裂強度について検討を行ったものである。結果として，主筋長期許容応力度時の最大曲げひび割れ幅の大きさは過大な値は認められず低品質再生骨材コンクリートを用いた問題は見出せなかった。また付着割裂強度は低品質再生骨材コンクリートおよび普通コンクリートを用いたシリーズの差異は認められなかった。普通コンクリートとの比較から低品質再生骨材コンクリートの構造用コンクリートとしての有効利用の可能性を明らかとした。
  • 日本学術振興会：科学研究費助成事業 挑戦的萌芽研究
    研究期間 : 2014年04月 -2016年03月 
    代表者 : 北垣 亮馬
     
    （1）高分子塗膜の紫外線を含む複数の劣化因子を分離して試験できる劣化試験装置を開発した．（2）昇温脱離法分析装置では，既往の方法と比較して，短時間で同時に複数種の気体について気体透過・拡散係数の測定が可能である．（3）塗膜はゴム状高分子と同様のFickの拡散法則，Henryの法則に従わず，ガラス状態として評価する必要がある．（4） 温湿度環境と材料それぞれとの組み合わせによって，物質移動の特性が異なる．（5）複数種類気体が透過,拡散する場合は相互作用がある可能性がある．（6）温湿度環境や可塑剤の影響で変化するガラス転移温度，自由体積と気体透過現象との関係については今後さらに検討が必要である．
  • 日本学術振興会：科学研究費助成事業 若手研究(B)
    研究期間 : 2012年04月 -2014年03月 
    代表者 : 北垣 亮馬
     
    コンクリート表面に微細凹凸を施すことで太陽からの日射における短波反射率を制御し，これによって，太陽から入射する熱を夏期には反射し，冬期には吸収できる熱収支に太陽光の角度依存性を織り込んだ，季節を問わずに省エネを実現できる建材表面の設計と熱収支のモデル化を行った．具体的には，セメント硬化体表面の反射率の角度依存性によって，熱移動にどのような影響を与え，結果として建築空間に適用された場合の空間の熱環境性能を評価するために，材料表面の凹凸に伴って変化する短波反射を含んだ熱収支モデルを提案し，その妥当性を実験とモデルの比較によって検証した．

教育活動情報

主要な担当授業

  • 建築施工特論
    開講年度 : 2021年
    課程区分 : 修士課程
    開講学部 : 工学院
  • 建築生産特論
    開講年度 : 2021年
    課程区分 : 修士課程
    開講学部 : 工学院
    キーワード : 建築施工、建築生産、寒冷地の建築材料の施工・生産・物性と劣化メカニズム
  • 建設材料学特論
    開講年度 : 2021年
    課程区分 : 修士課程
    開講学部 : 工学院
    キーワード : 建築施工、建築生産、寒冷地の建築材料の施工・生産・物性と劣化メカニズム
  • 建築施工特論
    開講年度 : 2021年
    課程区分 : 博士後期課程
    開講学部 : 工学院
  • 建築生産特論
    開講年度 : 2021年
    課程区分 : 博士後期課程
    開講学部 : 工学院
    キーワード : 建築施工、建築生産、寒冷地の建築材料の施工・生産・物性と劣化メカニズム
  • 建設材料学特論
    開講年度 : 2021年
    課程区分 : 博士後期課程
    開講学部 : 工学院
    キーワード : 建築施工、建築生産、寒冷地の建築材料の施工・生産・物性と劣化メカニズム
  • 建築都市学概論
    開講年度 : 2021年
    課程区分 : 学士課程
    開講学部 : 工学部
    キーワード : 都市再生、持続可能な都市、都市建築、都市住宅、都市の歴史、まちづくり、都市景観、都市環境、都市防災、
  • 情報学 Ⅰ
    開講年度 : 2021年
    課程区分 : 学士課程
    開講学部 : 全学教育
    キーワード : 情報活用，情報社会，情報科学，プログラミング，データサイエンス
  • 建築施工
    開講年度 : 2021年
    課程区分 : 学士課程
    開講学部 : 工学部
    キーワード : 建設業、建築工事、建設技術、品質管理、情報化施工、環境保全
  • 建築生産
    開講年度 : 2021年
    課程区分 : 学士課程
    開講学部 : 工学部
    キーワード : 建築生産，建築材料で起こっている問題意識の喚起，新しい建築材料のあり方を考える
  • 建設材料
    開講年度 : 2021年
    課程区分 : 学士課程
    開講学部 : 工学部
    キーワード : セメント，コンクリート，断熱材，外装材料，高分子，塗料，補修材，劣化，耐久性
  • 建築材料演習
    開講年度 : 2021年
    課程区分 : 学士課程
    開講学部 : 工学部
    キーワード : モルタル，コンクリート，鋼材，高分子，補修材料など建設材料の基本
  • 建築序説
    開講年度 : 2021年
    課程区分 : 学士課程
    開講学部 : 工学部
    キーワード : 建築思想、建築学の広がり、建築の基礎知識、建築の職能

大学運営

委員歴

  • 2020年04月 - 現在   The International Union of Laboratories and Experts in Construction Materials, Systems and Structures (RILEM)   TC-DOC 委員
  • 2020年04月 - 現在   The International Union of Laboratories and Experts in Construction Materials, Systems and Structures (RILEM)   TC-IMC 委員
  • 2018年04月 - 現在   日本建築仕上学会   論文集委員会 委員
  • 2017年04月 - 現在   日本建築仕上学会   理事
  • 2017年04月 - 現在   内外装工事運営委員会   委員
  • 2017年04月 - 現在   日本建築学会   材料施工委員会 内外装材運営委員会 発泡プラスチック断熱材の長期性能に関する検討WG 主査
  • 2017年04月 - 現在   日本建築学会   材料施工委員会 内外装工事運営委員会 左官材料WG 委員
  • 2017年04月 - 現在   日本建築学会   材料施工委員会 環境配慮運営委員会 委員
  • 2017年04月 - 現在   日本建築学会   材料施工委員会 解体工事小委員会 委員
  • 2021年04月 - 2023年03月   日本建築学会   論文集委員会 委員
  • 2021年04月 - 2022年03月   日本コンクリート工学会   コンクリート工学論文集編集委員会 委員
  • 2020年04月 - 2022年03月   日本建築学会   建築系高分子の耐久性・意匠性・環境性能の標準的な長期性能評価手法構築 委員長
  • 2020年04月 - 2021年03月   日本コンクリート工学会   技術講習委員会 幹事長
  • 2017年04月 - 2019年03月   日本建築学会   技術報告集 編集委員会 委員
  • 2016年04月 - 2018年03月   日本建築学会   建築雑誌編集委員会 幹事
  • 2013年04月 - 2018年03月   日本建築学会   材料施工委員会 熱環境建材 委員
  • 2010年04月 - 2016年03月   日本建築学会   材料施工委員会 再生骨材コンクリート研究小委員会 委員
  • 2010年04月 - 2012年03月   日本コンクリート工学会   サスティナビリティ委員会 幹事
  • 2006年04月 - 2011年03月   日本建築仕上学会   編集委員会 委員
  • 2008年04月 - 2010年03月   日本コンクリート工学会   コンクリートセクターにおける地球温暖化物質・廃棄物の最小化に関する研究委員会 委員

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