Journal of Advanced Concrete Technology最新文献_第5页

Study of Mechanical Properties of Silicate Minerals by Molecular Dynamics Simulation 硅酸盐矿物力学性质的分子动力学模拟研究

IF 2 4区工程技术

Journal of Advanced Concrete Technology Pub Date : 2023-11-22 DOI: 10.3151/jact.21.920

Takayoshi Fujimura, Yuji Hakozaki, Shunsuke Sakuragi, Yuu Nakajima, Kenta Murakami, Kiyoteru Suzuki, Ippei Maruyama, Takahiro Ohkubo

{"title":"Study of Mechanical Properties of Silicate Minerals by Molecular Dynamics Simulation","authors":"Takayoshi Fujimura, Yuji Hakozaki, Shunsuke Sakuragi, Yuu Nakajima, Kenta Murakami, Kiyoteru Suzuki, Ippei Maruyama, Takahiro Ohkubo","doi":"10.3151/jact.21.920","DOIUrl":"https://doi.org/10.3151/jact.21.920","url":null,"abstract":"The aging and damage of concrete buildings and structures is a problem in modern society. This is especially true for nuclear power plant buildings, which are required to have high safety standards. In this study, molecular dynamics simulations were performed to obtain mechanical properties for silicate minerals, including quartz, which is used as an aggregate in concrete. We also attempted to clarify phenomena including mechanical fracture. Mechanical properties of each mineral (Young's modulus, Poisson's ratio, and maximum stress) were obtained by performing tensile simulations on 10 silicate minerals which are α-quartz, Orthoclase, Microcline, Albite, Oligoclase, Andesine, Labradorite, Augite, Diopside and Forsterite. Minerals other than α-quartz were highly anisotropic with respect to Young's modulus. The maximum stress was highest for α-quartz, but once a fracture started, the development of large fractures progressed at once and the stress relaxed rapidly. Deformation and fracture of the mineral in response to strain were analyzed by extracting the non-affine component of the local displacement of atoms in tensile simulations. This analysis was able to explain the behavior of the stress-strain curve for each mineral. We also investigated how the composition of a mineral affects its mechanical fracture.\u0000","PeriodicalId":14868,"journal":{"name":"Journal of Advanced Concrete Technology","volume":"65 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2023-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138519146","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Discrete Element Modelling of Powder-compacted C-S-H Matrix 粉末压实C-S-H矩阵的离散元建模

IF 2 4区工程技术

Journal of Advanced Concrete Technology Pub Date : 2023-11-21 DOI: 10.3151/jact.21.889

Zhe Zhang, Guoqing Geng

引用次数: 0

Influence of Reinforcing Rebar on Expansion due to Delayed Ettringite Formation along the Bonding Length – Part II: Bond Performance of Reinforced Concrete Affected by DEF Expansion 延后钙矾石沿粘结长度形成对钢筋膨胀的影响——第二部分:DEF膨胀对钢筋混凝土粘结性能的影响

IF 2 4区工程技术

Journal of Advanced Concrete Technology Pub Date : 2023-11-18 DOI: 10.3151/jact.21.869

Taito Miura, Misato Fujishima, Yuichiro Kawabata, Stéphane Multon, Renaud-Pierre Martin, Naoshi Ueda, Yuya Takahashi, Shingo Asamoto, Jean-Francois Seignol

{"title":"Influence of Reinforcing Rebar on Expansion due to Delayed Ettringite Formation along the Bonding Length – Part II: Bond Performance of Reinforced Concrete Affected by DEF Expansion","authors":"Taito Miura, Misato Fujishima, Yuichiro Kawabata, Stéphane Multon, Renaud-Pierre Martin, Naoshi Ueda, Yuya Takahashi, Shingo Asamoto, Jean-Francois Seignol","doi":"10.3151/jact.21.869","DOIUrl":"https://doi.org/10.3151/jact.21.869","url":null,"abstract":"The purpose of this study is to clarify the bond behavior between rebar and concrete during DEF expansion and pullout testing. The details of the expansion test and the influence of reinforcing bar on DEF expansion have been precisely described in Part I. In Part II, the data related to the bond test is described. The change in bond behavior due to DEF expansion is investigated via the one-end pullout test and the influence of DEF expansion on the bond behavior is discussed. The local bond behavior (slip and bond stress) during the pullout test of the specimens without stirrups is observed to be dramatically changed by DEF expansion. Regarding the specimens with stirrups, failure did not occur during the pullout test and the local bond behavior slightly changed as in the case without stirrups. From the experimental results, a conceptual diagram is proposed to explain the bond behavior during DEF expansion and the pullout test based on the general conceptual understanding of the bond. It can be considered that the direction of local slip and local bond stress during the pullout test is opposite to that during the expansion process. This results in the observed complex local bond behavior during DEF expansion and the pullout test and the effect of stirrups on DEF expansion.\u0000","PeriodicalId":14868,"journal":{"name":"Journal of Advanced Concrete Technology","volume":"33 3","pages":""},"PeriodicalIF":2.0,"publicationDate":"2023-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138519135","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Experimental and Analytical Performance of Recycled Aggregates Produced by Customized Chemical-Mechanical Treatment 定制化学-机械处理再生骨料的实验与分析性能

4区工程技术

Journal of Advanced Concrete Technology Pub Date : 2023-11-15 DOI: 10.3151/jact.21.903

Babu Lal Chauhan, Gyani Jail Singh

{"title":"Experimental and Analytical Performance of Recycled Aggregates Produced by Customized Chemical-Mechanical Treatment","authors":"Babu Lal Chauhan, Gyani Jail Singh","doi":"10.3151/jact.21.903","DOIUrl":"https://doi.org/10.3151/jact.21.903","url":null,"abstract":"The purpose of this study is to evaluate the experimental and analytical performance of untreated recycled aggregates (URA), chemically treated recycled aggregates (ARA), and customized chemical-mechanically processed recycled aggregates (AmRA). The compressive strength, split tensile strength, flexural strength, fracture energy, and modulus of elasticity of concrete consisting of AmRA (AmRC) are greater than those composed by URA (URC) by 33.88%, 5.87%, 55.07%, 28.84%, and 50.80%, and those of ARA (ARC) by 10.89%, 21.41%, 29.44%, 55.33%, and 34.48%, respectively. AmRC has abrasion resistance around 52.03% and 43.07% higher than URC and ARC. Chemical treatment reduces porosity and microcracks in mortar adhered to aggregate. As a result of the customized mechanical treatment, the surface characteristics are highly uniform and dense. The high-quality surface texture, reduced porosity, and microcracks in the mortar adhering to the AmRA significantly strengthen interfacial transitions zones. Thus, AmRC achieves physical, mechanical, and durability properties close to or superior to natural aggregate (NA) concrete (NAC). Moreover, there is a strong correlation between compressive strength and split tensile strength, flexural strength, fracture energy, and modulus of elasticity of AmRC with URC and ARC. The most interesting observation of the present research is the equivalency in sorptivity of AmRC and NAC. The present study uses the URA produced by crushing concrete cubes in the laboratory.","PeriodicalId":14868,"journal":{"name":"Journal of Advanced Concrete Technology","volume":"16 10","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136227639","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Influence of Reinforcing Rebar on Expansion due to Delayed Ettringite Formation along the Bonding Length – Part I: The Role of Bond on Expansive Behavior of Concrete 钢筋沿黏结长度延迟形成钙矾石对膨胀的影响——第一部分:黏结对混凝土膨胀性能的作用

4区工程技术

Journal of Advanced Concrete Technology Pub Date : 2023-11-09 DOI: 10.3151/jact.21.851

Yuichiro Kawabata, Taito Miura, Misato Fujishima, Naoshi Ueda, Yuya Takahashi, Shingo Asamoto, Stéphane Multon, Renaud-Pierre Martin, Jean-Francois Seignol

{"title":"Influence of Reinforcing Rebar on Expansion due to Delayed Ettringite Formation along the Bonding Length – Part I: The Role of Bond on Expansive Behavior of Concrete","authors":"Yuichiro Kawabata, Taito Miura, Misato Fujishima, Naoshi Ueda, Yuya Takahashi, Shingo Asamoto, Stéphane Multon, Renaud-Pierre Martin, Jean-Francois Seignol","doi":"10.3151/jact.21.851","DOIUrl":"https://doi.org/10.3151/jact.21.851","url":null,"abstract":"This paper explores the effects of rebar as an internal restraint on the expansion of delayed ettringite formation (DEF) in concrete. Concrete specimens embedded with steel bars without end plates are subjected to heat treatment followed by immersion in water. The effect of stirrups on expansion is also investigated. The results show that the longitudinal expansion of specimens without stirrups differs depending on the longitudinal position, owing to the different degrees of restraint resulting from stress in the steel bar. The final transverse expansions of the specimens without stirrups are close to those measured for stress-free specimens. Conversely, longitudinal and transverse expansions are significantly reduced in the specimens with stirrups. This indicates that the combination of a longitudinal steel bar and stirrups induces three-dimensional confinement stresses that help to limit DEF expansion in both the longitudinal and transverse directions. Furthermore, possible debonding along the longitudinal bar is observed in specimens without stirrups when the transverse expansion of the prismatic specimens is 0.4 to 0.6%. This behavior is not observed in the specimens with stirrups, which demonstrates the effectiveness of three-dimensional restraints in significantly mitigating the risk of debonding, as well as DEF expansion.","PeriodicalId":14868,"journal":{"name":"Journal of Advanced Concrete Technology","volume":" 33","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135192268","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Incineration Bottom Ash as Aggregate for Controlled Low Strength Materials: Implications and Coping Strategies 焚烧底灰集料用于控制低强度材料:启示与应对策略

4区工程技术

Journal of Advanced Concrete Technology Pub Date : 2023-11-07 DOI: 10.3151/jact.21.837

Wei-Chien Wang, Jia-Chen Xue, Chia-Yun Huang, Hsiao-Chuan Chang

{"title":"Incineration Bottom Ash as Aggregate for Controlled Low Strength Materials: Implications and Coping Strategies","authors":"Wei-Chien Wang, Jia-Chen Xue, Chia-Yun Huang, Hsiao-Chuan Chang","doi":"10.3151/jact.21.837","DOIUrl":"https://doi.org/10.3151/jact.21.837","url":null,"abstract":"Most waste disposal methods in Taiwan involve incineration, the incineration bottom ash (IBA) which is accumulated over the years and needs urgent treatment. Hence, using IBA to create renewable materials is essential for the sustainable development. In this study, natural aggregates in the controlled low strength material (CLSM) were replaced with IBA. Its workability, setting time, unit weight, mechanical behavior, and environmental impact were examined. The study also looked at the characteristics of CLSM and suggested solutions for improvement. The results showed that the substitution of natural fine aggregates with IBA had the most significant impact on the engineering properties of CLSM. IBA significantly improves the workability and reduces the unit weight of CLSM, but the presence of CaSO4 had a detrimental effect on its setting time and mechanical behavior. However, treating IBA at 750℃ before use significantly improved the mechanical properties of IBA-CLSM and shortened its setting time, making it a potential permanent backfill structure. The toxicity test results showed that the IBA-CLSM produced had no threat to environmental safety. The study proved that using IBA produced in Taiwan to replace natural aggregates in CLSM was feasible and an effective way to utilize IBA.","PeriodicalId":14868,"journal":{"name":"Journal of Advanced Concrete Technology","volume":"3 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135431509","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Numerical Analysis of Impact Compression Failure and Dynamic Mechanical Behavior of Lightweight Aggregate Concrete at Low Temperatures 低温下轻骨料混凝土冲击压缩破坏及动态力学性能数值分析

4区工程技术

Journal of Advanced Concrete Technology Pub Date : 2023-10-27 DOI: 10.3151/jact.21.821

Zhengyu Duan, Zhiwu Zhu, Hongming Su, Fulai Zhang, Zhijian Mao

引用次数: 0

Influence of Temperature in the Early-age Elastic Modulus Evolution of Cement Pastes and Concrete 温度对水泥浆体和混凝土早期弹性模量演化的影响

4区工程技术

Journal of Advanced Concrete Technology Pub Date : 2023-10-26 DOI: 10.3151/jact.21.803

José Granja, Renan Rocha Ribeiro, Thomas Russo, Rodrigo Lameiras, Miguel Azenha

{"title":"Influence of Temperature in the Early-age Elastic Modulus Evolution of Cement Pastes and Concrete","authors":"José Granja, Renan Rocha Ribeiro, Thomas Russo, Rodrigo Lameiras, Miguel Azenha","doi":"10.3151/jact.21.803","DOIUrl":"https://doi.org/10.3151/jact.21.803","url":null,"abstract":"The influence of temperature on the hydration of cementitious materials has been traditionally modelled using the maturity concept and Arrhenius law. This approach yields a single material property, called apparent activation energy (Ea), that describes the whole temperature dependence. Determining Ea experimentally has sparked controversy, such as whether the different properties (e.g., compressive strength, tensile strength, E-modulus) exhibit different Ea, whether a single Ea value exists for the entire hydration process, or whether cement paste and concrete possess the same Ea. Furthermore, studies measuring Ea from elastic modulus measurements are truly scarce, likely due to experimental challenges with measuring this property at early-ages. This work investigated the influence of temperature on the elastic modulus evolution of cement paste and concrete. A single mix for each material was tested with the EMM-ARM (Elasticity Modulus Measurement through Ambient Response Method) methodology under three different isothermal conditions. The resulting elastic modulus evolution curves were used to derive Ea evolution curves from two traditional computation methods: the ‘speed’ method and the ‘derivative of speed’ method. Results showed that the elastic modulus evolution of both materials initially presented a constant Ea, independent of temperature and hydration development as preconized by the classical Arrhenius law. However, as hydration progressed to later stages, the activation energy exhibited evident dependencies on both temperature and hydration levels. Cement paste and concrete consistently exhibited different Ea values throughout hydration, with concrete having higher values. The use of the Ea curves to superimpose the different experimental elastic modulus evolution curves by means of the equivalent age concept led to near-perfect superpositions, strengthening the validity of this concept when applied to elastic modulus evolution.","PeriodicalId":14868,"journal":{"name":"Journal of Advanced Concrete Technology","volume":"11 4","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136377045","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Error Factors in Quantifying Inorganic Carbonate CO2 in Concrete Materials 无机碳酸盐CO2在混凝土材料中

4区工程技术

Journal of Advanced Concrete Technology Pub Date : 2023-10-21 DOI: 10.3151/jact.21.789

Haruka Takahashi, Ippei Maruyama, Takahiro Ohkubo, Ryoma Kitagaki, Yuya Suda, Atsushi Teramoto, Kazuko Haga, Takahiro Nagase

{"title":"Error Factors in Quantifying Inorganic Carbonate CO2 in Concrete Materials","authors":"Haruka Takahashi, Ippei Maruyama, Takahiro Ohkubo, Ryoma Kitagaki, Yuya Suda, Atsushi Teramoto, Kazuko Haga, Takahiro Nagase","doi":"10.3151/jact.21.789","DOIUrl":"https://doi.org/10.3151/jact.21.789","url":null,"abstract":"In this study, CO2 quantification was performed on various concrete binder and aggregates by back titration, ther-mogravimetric 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.","PeriodicalId":14868,"journal":{"name":"Journal of Advanced Concrete Technology","volume":"13 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135510699","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

An Adaptive Homogenization Scheme for Modeling the Effective Elastic Properties of Early Age Concrete 早期混凝土有效弹性特性建模的自适应均质化方案

4区工程技术

Journal of Advanced Concrete Technology Pub Date : 2023-09-20 DOI: 10.3151/jact.21.777

Tuan Nguyen-Sy, Minh-Quan Thai, Ngoc-Minh Vu

引用次数: 0