Magazine of Concrete Research最新文献_第9页

Effects of desalinated sea sand on the alkali-silica reaction of seawater and sea sand concrete 脱盐海砂对海水和海砂混凝土碱-硅反应的影响

4区工程技术

Magazine of Concrete Research Pub Date : 2023-11-11 DOI: 10.1680/jmacr.22.00202

Dehui Wang, Qingnan Gong, Surong Luo, Zhengxian Yang

{"title":"Effects of desalinated sea sand on the alkali-silica reaction of seawater and sea sand concrete","authors":"Dehui Wang, Qingnan Gong, Surong Luo, Zhengxian Yang","doi":"10.1680/jmacr.22.00202","DOIUrl":"https://doi.org/10.1680/jmacr.22.00202","url":null,"abstract":"The application of seawater and sea sand concrete (SWSSC) can reduce the construction period and cost of island infrastructure, but it may also bring the risk of alkali-silica reaction (ASR) due to the presence of alkali ions in seawater and sea sand. To compare the characteristics of ASR between SWSSC and seawater and desalinated sea sand (DSS) concrete and investigate the effects of desalinated sea sand on the ASR of SWSSC, the properties and the ASR products of mortar-bars with different desalinated sea sand content were investigated. When the DSS proportion increased from 0% to 100%, the Na + , K + , and Ca + concentration contents and pH of the specimens decreased by 22.6, 2.0, 45.1 mg·L + and 0.05, and the expansion of mortar bars reduced by 0.16%. Desalination of sea sand could not eliminate the risk of ASR of SWSSC completely. The 14 days expansion of mortar bars with 100% DSS was 0.13%, and the precursors of ASR-P1 were observed by SEM. The experimental results of XRD, FTIR, Raman spectrometer, DTA, SEM, and EDX all showed that with the increase of DSS proportion, the content of Na-shlykovite and ASR-P1 were gradually reduced. A small amount of Mg element in both Na-shlykovite and ASR-P1 was detected by EDX, but the mechanism of Mg element in ASR of SWSSC needs further study. This study can provide a basis for the application of SWSSC in island infrastructure.","PeriodicalId":18113,"journal":{"name":"Magazine of Concrete Research","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135042862","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

Meso-damage behavior of cement stabilized macadam for a long-time immersion based on particle flow theory 基于颗粒流理论的水泥稳定碎石长时间浸没细观损伤行为

4区工程技术

Magazine of Concrete Research Pub Date : 2023-11-10 DOI: 10.1680/jmacr.23.00012

Guofang Zhao, Chengcheng Luo, Xiaoyong Wu, Xinqiang Wang, Yongkang Yan, Zhanyou Yan

{"title":"Meso-damage behavior of cement stabilized macadam for a long-time immersion based on particle flow theory","authors":"Guofang Zhao, Chengcheng Luo, Xiaoyong Wu, Xinqiang Wang, Yongkang Yan, Zhanyou Yan","doi":"10.1680/jmacr.23.00012","DOIUrl":"https://doi.org/10.1680/jmacr.23.00012","url":null,"abstract":"Water can cause a certain degree of damage to cement stabilized macadam. If cement stabilized macadam is immersed in water for a long time, the degree of damage will be greater. In order to study the damage of cement stabilized macadam with long-time water immersion, a discrete element model of cement stabilized macadam was established in this paper. The Weibull distribution function was used to simulate the heterogeneous contact between particles. The parallel bond model was to simulate the material constitutive relationship. The microscopic parameters of cement-stabilized macadam were obtained by trial-and-error method. The stress-strain curve was obtained by immersion test. The micromechanics behavior of cement stabilized macadam after immersion was analyzed. The results show that the contact area and strength of cement stabilized macadamia immersed for 30 days are 31.4 % and 46 % smaller than that of not immersed macadamia. The force chains between particles are evenly distributed. At the loading peak, the normal contact force between particles is much larger than the tangential force, and the vertical force chain is much larger than the transverse force chain. The distribution of cementation energy/friction energy/impact energy is not uniform in the middle/peak loading stage.","PeriodicalId":18113,"journal":{"name":"Magazine of Concrete Research","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135186467","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

Simplified numerical model for the collapse analysis of RC frame under the oblique impact 斜交冲击下钢筋混凝土框架倒塌分析的简化数值模型

4区工程技术

Magazine of Concrete Research Pub Date : 2023-11-08 DOI: 10.1680/jmacr.23.00046

Yujing Zhou, Xiaowei Cheng, Yi Li, Fangfang Liu

{"title":"Simplified numerical model for the collapse analysis of RC frame under the oblique impact","authors":"Yujing Zhou, Xiaowei Cheng, Yi Li, Fangfang Liu","doi":"10.1680/jmacr.23.00046","DOIUrl":"https://doi.org/10.1680/jmacr.23.00046","url":null,"abstract":"The objective of this study is to develop a simplified numerical model that can be used to accurately and quickly conduct collapse analysis of a reinforced concrete (RC) frame impacted by a vehicle obliquely at 45°. The simplified numerical model included introduces a simplified RC frame and a simplified vehicle. For the simplified RC frame, a mixed modelling technique was used, in which structural components that experienced serious damage were simulated using detailed elements, while the retained structural components were simulated by larger elements. A constraint algorithm of nodal rigid body in LS-DYNA was adopted to guarantee the displacement compatibility of two kinds of element. For the simplified vehicle model, the spring–mass system was improved on the basis of the energy conservation principle to represent the vehicle in a 45° impact. Combining the simplified RC frame model and vehicle model, the impact response of an RC frame subjected to vehicle impact was studied and compared with the results of a detailed RC frame model impacted by a detailed vehicle. The validation confirmed that these introduced simplifications could significantly improve the computational efficiency and ensure the computational accuracy for the collapse analysis of an RC frame subjected to vehicle impact.","PeriodicalId":18113,"journal":{"name":"Magazine of Concrete Research","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135293375","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

Effects of mixture design parameters on the properties of belitic calcium sulfoaluminate concrete 配合比设计参数对贝理石型硫铝酸钙混凝土性能的影响

4区工程技术

Magazine of Concrete Research Pub Date : 2023-11-08 DOI: 10.1680/jmacr.23.00067

I. Aguilar Rosero, E.O. Soriano Somarriba, B. Farivar, C.D. Murray

{"title":"Effects of mixture design parameters on the properties of belitic calcium sulfoaluminate concrete","authors":"I. Aguilar Rosero, E.O. Soriano Somarriba, B. Farivar, C.D. Murray","doi":"10.1680/jmacr.23.00067","DOIUrl":"https://doi.org/10.1680/jmacr.23.00067","url":null,"abstract":"Belitic calcium sulfoaluminate (BCSA) cement has well-established advantages such as a fast setting time, fast strength gain, long-term strength, shrinkage and sustainability. BCSA cement reaches an initial set in about 15 min at room temperature and can reach compressive strengths of over 27 MPa in about 2 h. While it can be mixed in a similar fashion to Portland cement (PC), a set retarder (such as citric acid) is usually required to achieve adequate working time and the design of mixtures differs slightly from PC designs. This paper provides guidance on establishing mix design criteria for BCSA cement. Slump and compressive strength studies measurements were taken for varying mixture proportions with strengths measured up to 1 year of hydration. For BCSA concrete mixtures, a relationship between water content and slump was established. Citric acid was found to increase the slump, especially at lower water contents. A relationship between setting time and citric acid dosage was proposed on the basis of mortar penetrometer and Vicat needle tests. X-ray diffraction analysis was also conducted on BCSA cement pastes with different water/cement (w/c) ratios. Crystalline structure growth was found to be directly related to the w/c ratio and inversely proportional to compressive strength.","PeriodicalId":18113,"journal":{"name":"Magazine of Concrete Research","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135293276","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

Assessment of hybrid effect between polyethylene fiber and nano-calcium carbonate for flowability and strength of geopolymer composite 聚乙烯纤维与纳米碳酸钙杂化对地聚合物复合材料流动性和强度的影响

4区工程技术

Magazine of Concrete Research Pub Date : 2023-11-02 DOI: 10.1680/jmacr.23.00090

Hui Li, Li Li, Ning Zhang, Qi Feng

{"title":"Assessment of hybrid effect between polyethylene fiber and nano-calcium carbonate for flowability and strength of geopolymer composite","authors":"Hui Li, Li Li, Ning Zhang, Qi Feng","doi":"10.1680/jmacr.23.00090","DOIUrl":"https://doi.org/10.1680/jmacr.23.00090","url":null,"abstract":"Using geopolymer composites to reduce the use of Portland cement can decrease carbon dioxide emissions. The focus of this study was on improving the strength of a geopolymer composite by assessing the positive hybrid effect of nano-calcium carbonate (NCC) and polyethylene fibres (PFs) of different lengths (6 mm and 12 mm). Fresh and hardened properties, including flowability and strength, were investigated to evaluate the hybrid effect. Generally, the hybrid effects from the PFs of different lengths and NCC were negative for flowability, but the hybrid effects were positive on strength. The combination of 12 mm PF + 6 mm PF + 1% NCC was found to have the highest hybrid effect on bending strength, resulting from the good fibre–matrix bond. The bending strength of the PF-reinforced geopolymer composite was assessed based on a new regression coefficient (A), which takes into account the hybrid effect, the fibre–matrix bond strength and fibre dispersion. The new model for the bending strength of PF-reinforced geopolymer composites introduced in this paper is simpler and more effective than previous models provided in the literature.","PeriodicalId":18113,"journal":{"name":"Magazine of Concrete Research","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135874443","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

Comparison of thermal conductivity and electrical resistivity of carbon-based cementitious composites 碳基胶凝复合材料的导热率和电阻率比较

4区工程技术

Magazine of Concrete Research Pub Date : 2023-10-13 DOI: 10.1680/jmacr.22.00358

Fatih Acikök, Ahmet Genç, Oğuzhan Şahin, İsmail Raci Bayer, Mehmet Kemal Ardoğa, Mustafa Şahmaran

{"title":"Comparison of thermal conductivity and electrical resistivity of carbon-based cementitious composites","authors":"Fatih Acikök, Ahmet Genç, Oğuzhan Şahin, İsmail Raci Bayer, Mehmet Kemal Ardoğa, Mustafa Şahmaran","doi":"10.1680/jmacr.22.00358","DOIUrl":"https://doi.org/10.1680/jmacr.22.00358","url":null,"abstract":"In this study, it was aimed to produce the multifunctional cementitious composites with advanced thermal and electrical performance considering that these composites having high conductivity serve for the purpose of de-icing, electromagnetic shielding, anti-static, anti-corrosion, and so on. Carbon fiber (CF), and carbon powder (CP) were used singly or together to develop cementitious composites having high conductivity. The electrical resistance and thermal conductivity tests were performed to measure the conductivity of the cementitious composites. While mini-spreading test was applied to assess the consistency of the fresh-state cementitious composites containing conductive materials, in order to determine the distribution of the conductive material incorporated, SEM images were analyzed. In addition, compressive strength tests were carried out to determine the mechanical properties. According to the test results, the highest electrical conductivity result (197 Ω on the 1 st day) were obtained from the binary mixtures, while the highest thermal conductivity result (1250 mW/m.K on the 7 st day) were obtained from the mixtures containing only CP (by volume %0.6). 0.5% carbon fiber by volume mixture performed the worst in terms of mechanical and workability, with 20.5 MPa lower compressive strength and 16 cm lower mini-spread diameter values when compared to the control mixture.","PeriodicalId":18113,"journal":{"name":"Magazine of Concrete Research","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135918229","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 optimized performance of ultra-high performance silicomanganese slag concrete by water glass immersion 水玻璃浸渍法优化了超高性能硅锰渣混凝土的性能

4区工程技术

Magazine of Concrete Research Pub Date : 2023-10-05 DOI: 10.1680/jmacr.22.00353

Baifu Luo, Dong Wang, Mohamed Elchalakani

引用次数: 0

Impact of recycled concrete aggregates on the strength and durability properties of pervious concrete 再生混凝土骨料对透水混凝土强度和耐久性的影响

4区工程技术

Magazine of Concrete Research Pub Date : 2023-10-05 DOI: 10.1680/jmacr.23.00089

Mudasir Nazeer, Kanish Kapoor, S.P. Singh

{"title":"Impact of recycled concrete aggregates on the strength and durability properties of pervious concrete","authors":"Mudasir Nazeer, Kanish Kapoor, S.P. Singh","doi":"10.1680/jmacr.23.00089","DOIUrl":"https://doi.org/10.1680/jmacr.23.00089","url":null,"abstract":"The present investigation has been designed to assess the performance of pervious concrete prepared with Fly Ash (FA) and Recycled Concrete Aggregates (RCA) in place of Portland Cement (PC) and Natural Aggregates (NA). The percentage of NA replacement with RCA was in the proportion of 0%, 50%, and 100%, while the percentage of FA substitution was fixed at 10%. Various fresh (workability and consistency), mechanical (compressive strength, split tensile, and shear strength), durability (abrasion resistance, freeze thaw, flexure, and acid resistance), and microstructural (SEM and EDS) properties of pervious concrete have been evaluated at different curing periods. The findings reveal that the incorporation of RCA at different levels and partial substitution of FA proves to be desirable for the use of pervious concrete for structural and pavement construction purposes. Furthermore, incorporation of 10% FA in addition to higher levels of RCA proves significantly beneficial in refining the microstructural behaviour of pervious concrete. A homogenous micrograph with dense and layered C-S-H and C-H with was observed for mix made with 10% FA and 100% RCA.","PeriodicalId":18113,"journal":{"name":"Magazine of Concrete Research","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135482183","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

Performance testing of roof beam–column connections for precast N-system 预制n型体系屋面梁柱连接性能试验

4区工程技术

Magazine of Concrete Research Pub Date : 2023-10-03 DOI: 10.1680/jmacr.23.00037

Labeat Misini, Jelena Ristic, Viktor Hristovski, Danilo Ristic

{"title":"Performance testing of roof beam–column connections for precast N-system","authors":"Labeat Misini, Jelena Ristic, Viktor Hristovski, Danilo Ristic","doi":"10.1680/jmacr.23.00037","DOIUrl":"https://doi.org/10.1680/jmacr.23.00037","url":null,"abstract":"The precast N-system based on embedded-pin connections is used widely for constructing large precast industrial halls in south-eastern Europe and further afield, including areas of high seismicity. To assess realistically the seismic performances, safety margins and limitations of the connections, experimental investigations are essential. Experimental results from laboratory tests on a large-scale prototype model of the original roof beam–column connection show its actual bearing capacity, damage propagation pattern and specific failure mode. The experimental study was then extended to a prototype model of an upgraded roof beam–column connection. For better safety, the connection was upgraded with improved concrete confinement and stronger steel connecting pins. The experimental results show clearly that the implemented method for upgrading the pin-based connection provided very limited upgrading effects. To obtain much better and more reliable safety upgrading, a new innovative and effective upgrading method had to be developed. The capability of the implemented refined nonlinear three-dimensional micro-modelling concept to simulate realistically the complex nonlinear response of the tested original and upgraded roof beam–column connections was demonstrated by an extensive analytical simulation study.","PeriodicalId":18113,"journal":{"name":"Magazine of Concrete Research","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135743634","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

Erratum 勘误表

IF 2.7 4区工程技术

Magazine of Concrete Research Pub Date : 2023-10-01 DOI: 10.1680/jmacr.2023.75.20.1080

引用次数: 0