Journal of Advanced Concrete Technology最新文献_第2页

Test Method of Segregation Resistance of High Fluidity Concrete Based on Numerical Simulation of Dynamic Segregation of Coarse Aggregate 基于粗骨料动态离析数值模拟的高流动性混凝土抗离析性测试方法

IF 2 4区工程技术

Journal of Advanced Concrete Technology Pub Date : 2024-06-19 DOI: 10.3151/jact.22.372

Zhisong Xu, Zhuguo Li, Jiaping Liu, Wei Chen, Jianzhong Liu, Fangyu Han

{"title":"Test Method of Segregation Resistance of High Fluidity Concrete Based on Numerical Simulation of Dynamic Segregation of Coarse Aggregate","authors":"Zhisong Xu, Zhuguo Li, Jiaping Liu, Wei Chen, Jianzhong Liu, Fangyu Han","doi":"10.3151/jact.22.372","DOIUrl":"https://doi.org/10.3151/jact.22.372","url":null,"abstract":"The workability of high fluidity concrete (HFC) also depends on its segregation resistance besides fluidity, and gap-passing ability, etc. Currently, there is a lack of easy, quantitative method for evaluating segregation resistance. Efficient assessment is crucial for construction applications of HFC. This paper aims to propose a simple test method for the segregation resistance of HFC on basis of the J-ring test that has been generally used for evaluating the fluidity and passing ability of HFC. Experiment and numerical simulation of J-ring test were conducted for HFCs with different fluidity and segregation resistance. The fresh concretes were treated as two-phase granular fluids of matrix mortar and coarse aggregate in simulation by a newly developed particle meshless method, called DPMP-MPS. The flow and segregation behaviors of the HFCs during J-ring test under different lifting speeds of slump cone were investigated. The numerical results demonstrate a close correlation between the final flow value to slump value ratio (SF-J/SL-J ratio) and the segregation resistances of HFCs. Consequently, the J-ring test can assess the segregation resistance based on the SF-J/SL-J ratio. Notably, it emphasizes that, for precise evaluation of HFC workability using the J-ring test, the lifting speed of the slump cone should fall within the range of 10 to 15 cm/s.\u0000","PeriodicalId":14868,"journal":{"name":"Journal of Advanced Concrete Technology","volume":"141 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2024-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141511575","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

Developing High-Strength Geopolymer using Least Activator and Pressure-Applied Casting: Techno-Enviro-Economic Performance 利用最少活化剂和压力浇注法开发高强度土工聚合物：技术-环境-经济性能

IF 2 4区工程技术

Journal of Advanced Concrete Technology Pub Date : 2024-06-05 DOI: 10.3151/jact.22.327

Khuram Rashid, Fahad Masud

{"title":"Developing High-Strength Geopolymer using Least Activator and Pressure-Applied Casting: Techno-Enviro-Economic Performance","authors":"Khuram Rashid, Fahad Masud","doi":"10.3151/jact.22.327","DOIUrl":"https://doi.org/10.3151/jact.22.327","url":null,"abstract":"This work is designed by coupling fly ash (FA) with dune sand (DS) for high-strength geopolymer activated in an alkaline environment under pressure-applied casting. Initially, the proportion of FA and DS is optimized with the least activator dosage to obtain higher than the compressive strength of 50 MPa. A uniaxial pressure is applied on a semi-dry mixture containing the least activators and immediately demolded, involving rapid production for the industrialization purpose of the paving blocks. The experimental study revealed that the FA-DS proportion of 1:1, with a liquid-to-solid ratio of 0.16, achieved a compressive strength of 54.4 MPa. Consequently, the coupling of DS provides an occupying effect and reduces the required activator quantity. The strength gain mechanism is discussed at the molecular level by analyzing Fourier-transform infrared. Finally, the technical performance of the strength and the density is evaluated on the real size 203 × 101 × 80 mm prism and compared with the commercially available conventional concrete blocks. Besides, the enviro-economic performance in terms of CO2 emissions and the cost are analysed as well. It is concluded that the developed block is a more environmentally sustainable and economically viable alternative to conventional concrete blocks.\u0000","PeriodicalId":14868,"journal":{"name":"Journal of Advanced Concrete Technology","volume":"70 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2024-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141259329","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

Polymer/Carbon Fiber Co-modification: Dynamic Compressive Mechanical Properties of Carbon Fiber Modified Polymer Reinforced Concrete 聚合物/碳纤维共改性：碳纤维改性聚合物加固混凝土的动态压缩力学性能

IF 2 4区工程技术

Journal of Advanced Concrete Technology Pub Date : 2024-05-10 DOI: 10.3151/jact.22.267

Zhihang Wang, Erlei Bai, Chaojia Liu, Yuhang Du, Biao Ren

{"title":"Polymer/Carbon Fiber Co-modification: Dynamic Compressive Mechanical Properties of Carbon Fiber Modified Polymer Reinforced Concrete","authors":"Zhihang Wang, Erlei Bai, Chaojia Liu, Yuhang Du, Biao Ren","doi":"10.3151/jact.22.267","DOIUrl":"https://doi.org/10.3151/jact.22.267","url":null,"abstract":"To explore the dynamic compressive mechanical properties of carbon fiber modified polymer reinforced concrete (CFMPRC), the 100 mm diameter SHPB (Split Hopkinson Pressure Bar) test system was used to carry out impact compression tests of CFMPRC with different carbon fiber volume content (0.1%, 0.2%, 0.3% and 0.4%). The dynamic stress-strain curves and fracture morphology of CFMPRC under different strain rates (37.7 s-1 to 132.2 s-1) were obtained, and the effects of strain rate and carbon fiber content on dynamic compressive strength, deformation and toughness of CFMPRC were analyzed. The results show that the dynamic compressive strength, deformation and toughness of CFMPRC have obvious strain rate strengthening effect and carbon fiber strengthening effect. The dynamic compressive strength, dynamic increase factor (DIF), dynamic peak strain and impact toughness of CFMPRC increase with strain rate gradually. The dynamic compressive mechanical properties of polymer reinforced concrete are improved by adding carbon fiber, and the optimal carbon fiber content is 0.2%. When carbon fiber content is 0.2%, the strain rate sensitivity of CFMPRC is the strongest, and the increase of strength is the maximum. Carbon fiber can bridge the internal cracks of concrete, and shows the co-modification effect with polymer. Polymer can enhance the carbon fiber/concrete matrix interface, which makes carbon fiber exert its effect more effectively.\u0000","PeriodicalId":14868,"journal":{"name":"Journal of Advanced Concrete Technology","volume":"19 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2024-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140925450","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

Freeze-thaw Resistance of Concrete using Ground Granulated Blast-furnace Slag and Blast-furnace Slag Sand in Salt Water 使用磨细高炉矿渣和高炉矿渣砂的混凝土在盐水中的抗冻融性

IF 2 4区工程技术

Journal of Advanced Concrete Technology Pub Date : 2024-05-09 DOI: 10.3151/jact.22.253

Toshiki Ayano, Takashi Fujii, Kanako Okazaki

{"title":"Freeze-thaw Resistance of Concrete using Ground Granulated Blast-furnace Slag and Blast-furnace Slag Sand in Salt Water","authors":"Toshiki Ayano, Takashi Fujii, Kanako Okazaki","doi":"10.3151/jact.22.253","DOIUrl":"https://doi.org/10.3151/jact.22.253","url":null,"abstract":"The freeze-thaw resistance of concrete is significantly lower in salt water than in fresh water. Concrete deteriorates through repeated freezing and thawing, but in salt water, freezing alone leads to destruction. This paper investigated the effect of calcium hydroxide in concrete on the failure of concrete under such low temperatures. Calcium hydroxide precipitates at the transition zone between aggregate and cement paste due to the hydration of cement. The lower the temperature and the higher the concentration of salt water, the more calcium hydroxide dissolves. From concrete, more calcium hydroxide is eluted in salt water than in fresh water. This accelerates the deterioration of mortar and concrete due to freeze-thaw action. Mortar and concrete using ground granulated blast-furnace slag produces less calcium hydroxide. In mortar and concrete using blast-furnace slag sand, calcium hydroxide precipitated around the aggregate reacts with cement paste and blast-furnace slag sand to modify the transition zone. From these results, it was clarified that concrete using blast-furnace slag exhibits high freeze-thaw resistance even in salt water.This paper is the English translation of the authors’ previous work [Ayano, T., Fujii, T. and Okazaki, K., (2023). “Freeze-thaw resistance of concrete using ground granulated blast-furnace and blast-furnace slag sand in salt water.” Japanese Journal of JSCE, 79(12), 23-00042. (in Japanese)].\u0000","PeriodicalId":14868,"journal":{"name":"Journal of Advanced Concrete Technology","volume":"26 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2024-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140942399","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

Time Dependency and Similarity of Water Permeability of Fly Ash Concrete Between Laboratory Environment and Site Environment 粉煤灰混凝土透水性在实验室环境和现场环境中的时间依赖性和相似性

IF 2 4区工程技术

Journal of Advanced Concrete Technology Pub Date : 2024-04-19 DOI: 10.3151/jact.22.219

Junzhi Zhang, Libin Zhou, Yucheng He, Yurong Zhang

{"title":"Time Dependency and Similarity of Water Permeability of Fly Ash Concrete Between Laboratory Environment and Site Environment","authors":"Junzhi Zhang, Libin Zhou, Yucheng He, Yurong Zhang","doi":"10.3151/jact.22.219","DOIUrl":"https://doi.org/10.3151/jact.22.219","url":null,"abstract":"Effects of fly ash (FA) content and environmental factors on the water permeability were studied, and the similarity relationship of time-dependent water permeability coefficient in site and laboratory environment was discussed. Meanwhile, the main microstructure parameters and their time-dependent characteristics were analyzed by the NMR method. Finally, the correlation between water permeability and porosity in two environments was analyzed. Results show that water permeability coefficient of FA concrete both decreased with exposure time in two environments. FA can effectively improve the water impermeability, and the improvement effect increased with FA content in the later exposure period. Laboratory environment accelerated the decrease of water permeability and porosity. However, in the later stage, the decrease degree was not as good as that in the site environment. Pores with size of 10 to 100 nm occupy the main part of pores in FA concrete and the proportion of harmful pores of diameter 100 nm or larger decreased with exposure time. The water permeability coefficient and porosity of concrete exposed for 520 days in laboratory are close to that exposed for 800 to 1000 days in site, showing a good time dependent correlation in both environments, and the correlation with exposure time is stronger than that considering FA content.\u0000","PeriodicalId":14868,"journal":{"name":"Journal of Advanced Concrete Technology","volume":"21 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2024-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140624070","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

CO2 Sequestration Through Aqueous Carbonation of Electric Arc Furnace Slag 通过电弧炉炉渣水碳化封存二氧化碳

IF 2 4区工程技术

Journal of Advanced Concrete Technology Pub Date : 2024-04-12 DOI: 10.3151/jact.22.207

Francesca Bonfante, Giuseppe Ferrara, Pedro Humbert, Davide Garufi, Jean-Marc Christian Tulliani, Paola Palmero

引用次数: 0

Assessment on Bond Strength of CFRP Sheet Bonded to Concrete Focused on Sheet Stiffness 以片材刚度为重点评估与混凝土粘接的 CFRP 片材的粘接强度

IF 2 4区工程技术

Journal of Advanced Concrete Technology Pub Date : 2024-04-05 DOI: 10.3151/jact.22.190

Mitsuhiko Ozaki, Yasuhiko Sato, Eiji Yoshida, Aya Takeuchi, Yuta Yamada, Fumiaki Nagashima

{"title":"Assessment on Bond Strength of CFRP Sheet Bonded to Concrete Focused on Sheet Stiffness","authors":"Mitsuhiko Ozaki, Yasuhiko Sato, Eiji Yoshida, Aya Takeuchi, Yuta Yamada, Fumiaki Nagashima","doi":"10.3151/jact.22.190","DOIUrl":"https://doi.org/10.3151/jact.22.190","url":null,"abstract":"In previous studies on the bond behaviors of FRP sheets attached to concrete, specimens for bond tests that contained FRP sheets with relatively low stiffnesses were used. However, in actual strengthening design, high stiffnesses of FRP sheets are required because the scale of the structure is very large. Therefore, in this study, bond tests were conducted using specimens with many different sheet stiffnesses and with polyurea resin. As a result, the bond strength increased as the stiffness increased with multiple CFRP sheets. Nevertheless, existing bond strength models overestimated the bond strength when the stiffness exceeded 200 kN/mm. In addition, 3D scanning measurements of patterned and indented concrete thin layers behind CFRP sheets revealed that the interfacial fracture energy was strongly related to the surface area of the concrete thin layer, not to the CFRP sheet stiffness or the resin properties.This paper is an English translation of the authors’ previous work [Ozaki, M., Sato, Y., Yoshida, E., Takeuchi, A., Yamada, Y. and Nagashima, F., (2023). “Assessment on bond strength of CFRP sheet bonded to concrete focused on sheet stiffness.” Journal of JSCE, 79(6), 22-00289. (in Japanese)].\u0000","PeriodicalId":14868,"journal":{"name":"Journal of Advanced Concrete Technology","volume":"23 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2024-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140585012","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

Bond Strength of Post-installed Anchor Adhering to Damaged Concrete by Freeze-thaw Action 冻融作用下后置锚固件与受损混凝土的粘结强度

IF 2 4区工程技术

Journal of Advanced Concrete Technology Pub Date : 2024-04-03 DOI: 10.3151/jact.22.178

Yuga Yano, Taito Shiokoshi, Yuya Takase, Yutaro Ishida, Takahide Abe, Muneomi Takahashi, Tsutomu Ishigaki

{"title":"Bond Strength of Post-installed Anchor Adhering to Damaged Concrete by Freeze-thaw Action","authors":"Yuga Yano, Taito Shiokoshi, Yuya Takase, Yutaro Ishida, Takahide Abe, Muneomi Takahashi, Tsutomu Ishigaki","doi":"10.3151/jact.22.178","DOIUrl":"https://doi.org/10.3151/jact.22.178","url":null,"abstract":"Reinforced concrete (RC) structures in cold regions are susceptible to surface deterioration due to freeze-thaw cycles (FTC). For sustainable development goals (SDGs) and a decarbonized society, damaged structures should be repaired and reinforced. Post-installed anchors are commonly used for seismic retrofitting and equipment fixation. However, research on the bond characteristics of damaged concrete is limited. Therefore, in this study, the bonding performance of adhesive anchors in damaged concrete was investigated. Liquid nitrogen was employed to subject the concrete surface to FTC; subsequently, bond-slip tests were conducted with the degree of deterioration serving as a parameter. The results suggested, the bond strength decreased as the degree of damage increased. The reduction ratios of the post-installed anchor with epoxy and cement-based resins were almost identical. Furthermore, a bond strength equation was proposed by referring to the bond-slip model between the rebar and concrete (fib 1990). The test results were well predicted with a correlation coefficient of 0.94. This study is based on previous studies (Yano et al. 2022, 2023) but presents new findings.\u0000","PeriodicalId":14868,"journal":{"name":"Journal of Advanced Concrete Technology","volume":"14 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2024-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140584591","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

The GBESO Method Based on FEA with Discrete Models and Application for Aided Design to Members in RC D-Region 基于离散模型有限元分析的 GBESO 方法及其在 RC D 区构件辅助设计中的应用

IF 2 4区工程技术

Journal of Advanced Concrete Technology Pub Date : 2024-03-29 DOI: 10.3151/jact.22.162

Hu-zhi Zhang, Yi-jun Kang, Li-kun Li, Jian-qun Wang

{"title":"The GBESO Method Based on FEA with Discrete Models and Application for Aided Design to Members in RC D-Region","authors":"Hu-zhi Zhang, Yi-jun Kang, Li-kun Li, Jian-qun Wang","doi":"10.3151/jact.22.162","DOIUrl":"https://doi.org/10.3151/jact.22.162","url":null,"abstract":"To better utilize topology optimization theory to assist in designing reinforced concrete (RC) D-region members, a novel application mode, the Genetic Bi-directional Evolutionary Structural Optimization (GBESO) method based on Finite Element Analysis (FEA) with discrete models is proposed. Correspondingly a design method for reinforcement layout of RC D-region members is also derived. Non-linear FEA verification is conducted on numerical examples involving deep beams with openings. The results demonstrate that the GBESO algorithm exhibits better global optimization capacities compared to Evolutionary Structural Optimization-type (ESO-type) algorithms. It also provides rebar topologies that are more in line with the optimization objective, bringing lower steel consumption and higher rebar utilization rates. Moreover, by introducing inclined rebar to the members, their shear strength is enhanced to a level comparable to the flexural one, significantly improving ultimate load-bearing capacity, elastoplastic deformation capacity, and better ductility compared to empirical method. \u0000","PeriodicalId":14868,"journal":{"name":"Journal of Advanced Concrete Technology","volume":"53 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2024-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140325451","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

The Effect of SCMs on the Resistance of Steam-cured Concrete to Chloride Attack in the Tidal Zone of Real Marine Environment 单体材料对真实海洋环境潮汐区蒸汽养护混凝土抗氯化物侵蚀能力的影响

IF 2 4区工程技术

Journal of Advanced Concrete Technology Pub Date : 2024-03-26 DOI: 10.3151/jact.22.149

Xiaofeng Han, Lixiao Zhao, Xiaoguang Sun, Li Tian, Zhenxing Du, Penggang Wang

{"title":"The Effect of SCMs on the Resistance of Steam-cured Concrete to Chloride Attack in the Tidal Zone of Real Marine Environment","authors":"Xiaofeng Han, Lixiao Zhao, Xiaoguang Sun, Li Tian, Zhenxing Du, Penggang Wang","doi":"10.3151/jact.22.149","DOIUrl":"https://doi.org/10.3151/jact.22.149","url":null,"abstract":"Steam curing is a widely used technique for producing precast concrete components in practical engineering. Chloride attack is a main factor that leads to the corrosion of rebars in concrete structures, which significantly affects the durability and safety of concrete structures in marine environments. In this paper, XRD, LF-NMR, 29Si NMR, and 27Al NMR were used to investigate the microstructure evolution of steam-cured concrete and standard-cured concrete. Then, the steam-cured and standard-cured concrete were subjected to actual marine exposure tests to explore the microstructure evolution of concrete and the chloride erosion behavior in the tidal zone. The results showed that steam-curing can increase the average molecular chain length (MCL) and polymerization degree of C-(A)-S-H, promote the transformation of silicon-oxygen tetrahedral dimer to polymer, and increase the Q2/Q1 value of steam-cured concrete to twice that of standard-cured concrete. Compared to standard-cured specimens, steam-cured concrete specimens had significantly more harmful pores and multi-harmful pores. With the increase of exposure time to the marine environment, the depth of the convection zone inside the concrete did not change significantly, however, the peak value of chloride concentration increased gradually. The addition of SCMs to steam-cured concrete reduced the content of free and total chloride, which was well explained by microscopic tests. The concentration of chloride on the surface and chloride diffusion coefficient of steam-cured concrete showed a quadratic function relationship with the increase of slag content, and an exponential decay relationship with the content of fly ash.\u0000","PeriodicalId":14868,"journal":{"name":"Journal of Advanced Concrete Technology","volume":"61 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2024-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140313091","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