首页 > 最新文献

Magazine of Concrete Research最新文献

英文 中文
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 Q1 Engineering Pub Date : 2023-11-11 DOI: 10.1680/jmacr.22.00202
Dehui Wang, Qingnan Gong, Surong Luo, Zhengxian Yang
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.
海水和海砂混凝土(SWSSC)的应用可以缩短海岛基础设施的建设周期和成本,但也可能由于海水和海砂中存在碱离子而带来碱-硅反应(ASR)的风险。为了比较SWSSC与海水和海水淡化海砂(DSS)混凝土的ASR特性,研究海水淡化海砂对SWSSC ASR的影响,研究了不同海水淡化海砂含量砂浆棒的性能和ASR产物。当DSS比例从0%增加到100%时,试件的Na +、K +、Ca +浓度含量和pH分别降低了22.6、2.0、45.1 mg·L +和0.05,砂浆条的膨胀率降低了0.16%。海砂淡化并不能完全消除SWSSC的ASR风险。100% DSS砂浆条14 d膨胀率为0.13%,扫描电镜观察到ASR-P1前体。XRD、FTIR、拉曼光谱仪、DTA、SEM、EDX等实验结果均表明,随着DSS比例的增加,Na-shlykovite和ASR-P1的含量逐渐降低。EDX在Na-shlykovite和ASR- p1中均检测到少量Mg元素,但Mg元素在SWSSC ASR中的作用机制有待进一步研究。本研究可为SWSSC在海岛基础设施中的应用提供依据。
{"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 Q1 Engineering Pub Date : 2023-11-10 DOI: 10.1680/jmacr.23.00012
Guofang Zhao, Chengcheng Luo, Xiaoyong Wu, Xinqiang Wang, Yongkang Yan, Zhanyou Yan
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.
水会对水泥稳定碎石体造成一定程度的破坏。水泥稳定碎石如果长期浸泡在水中,其破坏程度会更大。为了研究水泥稳定碎石在长时间浸水作用下的损伤,建立了水泥稳定碎石的离散元模型。采用威布尔分布函数模拟颗粒间的非均匀接触。采用平行键模型模拟材料本构关系。采用试错法获得了水泥稳定碎石的微观参数。通过浸渍试验得到了应力-应变曲线。对水泥稳定碎石浸没后的细观力学行为进行了分析。结果表明,水泥稳定30 d的夏威夷果的接触面积和强度分别比未浸泡的夏威夷果小31.4%和46%。粒子间的力链分布均匀。在加载峰值处,颗粒间法向接触力远大于切向力,垂直力链远大于横向力链。在加载中峰阶段,胶结能/摩擦能/冲击能分布不均匀;
{"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 Q1 Engineering Pub Date : 2023-11-08 DOI: 10.1680/jmacr.23.00046
Yujing Zhou, Xiaowei Cheng, Yi Li, Fangfang Liu
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.
本研究的目的是开发一种简化的数值模型,该模型可用于准确、快速地进行钢筋混凝土(RC)框架在45°斜面上受到车辆撞击的倒塌分析。简化的数值模型包括一个简化的钢筋混凝土框架和一个简化的车辆。对于简化的钢筋混凝土框架,采用混合建模技术,其中结构构件遭受严重破坏时使用细部单元模拟,而保留的结构构件则使用较大的单元模拟。采用LS-DYNA中节点刚体约束算法,保证了两种单元的位移协调。对于简化的车辆模型,基于能量守恒原理对弹簧-质量系统进行了改进,以表示45°碰撞时的车辆。将简化的RC框架模型与车辆模型相结合,研究了RC框架在车辆冲击下的冲击响应,并与详细的RC框架模型在车辆冲击下的结果进行了比较。验证结果表明,这些简化方法能够显著提高计算效率,保证钢筋混凝土框架在车辆碰撞作用下的倒塌分析的计算精度。
{"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 Q1 Engineering Pub Date : 2023-11-08 DOI: 10.1680/jmacr.23.00067
I. Aguilar Rosero, E.O. Soriano Somarriba, B. Farivar, C.D. Murray
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.
白石质硫铝酸钙(BCSA)水泥具有固化时间快、强度增益快、强度长期稳定、收缩率高、可持续性好等优点。BCSA水泥在室温下约15分钟达到初凝,约2小时可达到27 MPa以上的抗压强度。虽然BCSA水泥的混合方式与波特兰水泥(PC)类似,但通常需要使用固定缓凝剂(如柠檬酸)来达到足够的工作时间,并且混合物的设计与PC设计略有不同。本文为建立BCSA水泥配合比设计准则提供了指导。坍落度和抗压强度研究测量采取了不同的混合比例的强度测量到1年的水化。对于BCSA混凝土配合比,建立了含水量与坍落度之间的关系。柠檬酸增加了坍落度,特别是在含水量较低的情况下。在砂浆渗透仪和维卡针试验的基础上,提出了凝结时间与柠檬酸用量的关系。对不同水灰比(w/c)的BCSA水泥浆体进行了x射线衍射分析。晶体结构的生长与w/c比成正比,与抗压强度成反比。
{"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 Q1 Engineering Pub Date : 2023-11-02 DOI: 10.1680/jmacr.23.00090
Hui Li, Li Li, Ning Zhang, Qi Feng
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.
使用地聚合物复合材料来减少波特兰水泥的使用可以减少二氧化碳的排放。本研究的重点是通过评估不同长度(6毫米和12毫米)的纳米碳酸钙(NCC)和聚乙烯纤维(PFs)的正杂化效应来提高地聚合物复合材料的强度。研究了混合效果的新鲜和硬化性能,包括流动性和强度。一般来说,不同长度的PFs和NCC的杂化效应对流动性是负的,而对强度是正的。12 mm PF + 6 mm PF + 1% NCC的组合对抗弯强度的混杂效应最高,这是由于良好的纤维基质结合。考虑混杂效应、纤维基质结合强度和纤维分散等因素,采用新的回归系数(a)对pf增强地聚合物复合材料的抗弯强度进行了评价。本文提出的pf增强地聚合物复合材料抗弯强度计算模型比已有的模型更简单、更有效。
{"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 Q1 Engineering 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
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.
在本研究中,考虑到这些复合材料具有高导电性,可用于除冰、电磁屏蔽、防静电、防腐等目的,旨在生产具有先进热电性能的多功能胶凝复合材料。采用碳纤维(CF)和碳粉(CP)单独或共同制备了高导电性的胶凝复合材料。通过电阻测试和导热测试来测量胶凝复合材料的导电性能。采用微扩散试验来评估含导电材料的新鲜状态胶凝复合材料的一致性,为了确定所含导电材料的分布,分析了SEM图像。此外,还进行了抗压强度试验,以确定其力学性能。试验结果表明,二元混合物第1天电导率最高(197 Ω),导热系数最高(1250 mW/m)。仅含CP(体积%0.6)的混合物中获得了第7天的K。0.5%体积碳纤维混合料的力学性能和和易性最差,与对照混合料相比,抗压强度降低20.5 MPa,微展径值降低16 cm。
{"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 Q1 Engineering Pub Date : 2023-10-05 DOI: 10.1680/jmacr.22.00353
Baifu Luo, Dong Wang, Mohamed Elchalakani
Silicomanganese slag (SS) is a byproduct of the ferroalloy industry and cause environmental pollution and consume resources. In this study, the authors explored the use of water glass immersion to improve the performance of SS and used it to produce ultra-high performance concrete (UHPC). The results showed that SS treating with a 2% water glass concentration for 24 hours resulted 16 MPa higher compressive strength for composite than pure UHPC. Additionally, the treated composite had approximately half the mass and compressive strength losses of pure UHPC after freeze-thaw test, indicating that the treatment had a significant positive effect on the freeze-thaw resistance of ultra-high silicomanganese slag performance concrete (UHPSSC). Micro-structural analysis also showed that water glass immersion optimized the morphology of UHPSSC, contributing to improved mechanical performance and freeze-thaw resistance of the composite.
硅锰渣是铁合金工业的副产物,对环境造成污染,消耗资源。在本研究中,作者探索了使用水玻璃浸泡来提高SS的性能,并将其用于生产超高性能混凝土(UHPC)。结果表明:水玻璃浓度为2%的SS处理24h后,复合材料的抗压强度比纯UHPC提高了16 MPa;此外,经冻融试验,处理后的复合材料的质量和抗压强度损失约为纯UHPC的一半,表明该处理对超高硅锰渣性能混凝土(UHPSSC)的抗冻融性能有显著的积极影响。微观结构分析还表明,水玻璃浸渍优化了UHPSSC的形貌,提高了复合材料的力学性能和抗冻融性能。
{"title":"The optimized performance of ultra-high performance silicomanganese slag concrete by water glass immersion","authors":"Baifu Luo, Dong Wang, Mohamed Elchalakani","doi":"10.1680/jmacr.22.00353","DOIUrl":"https://doi.org/10.1680/jmacr.22.00353","url":null,"abstract":"Silicomanganese slag (SS) is a byproduct of the ferroalloy industry and cause environmental pollution and consume resources. In this study, the authors explored the use of water glass immersion to improve the performance of SS and used it to produce ultra-high performance concrete (UHPC). The results showed that SS treating with a 2% water glass concentration for 24 hours resulted 16 MPa higher compressive strength for composite than pure UHPC. Additionally, the treated composite had approximately half the mass and compressive strength losses of pure UHPC after freeze-thaw test, indicating that the treatment had a significant positive effect on the freeze-thaw resistance of ultra-high silicomanganese slag performance concrete (UHPSSC). Micro-structural analysis also showed that water glass immersion optimized the morphology of UHPSSC, contributing to improved mechanical performance and freeze-thaw resistance of the composite.","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":"135483088","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
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 Q1 Engineering Pub Date : 2023-10-05 DOI: 10.1680/jmacr.23.00089
Mudasir Nazeer, Kanish Kapoor, S.P. Singh
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.
本研究旨在评估用粉煤灰(FA)和再生混凝土骨料(RCA)代替波特兰水泥(PC)和天然骨料(NA)制备透水混凝土的性能。RCA替代NA的比例分别为0%、50%和100%,FA替代的比例固定为10%。透水混凝土的各种新鲜(和易性和一致性)、机械(抗压强度、劈裂拉伸和剪切强度)、耐久性(耐磨性、冻融性、抗弯性和耐酸性)和微观结构(SEM和EDS)性能在不同的养护期进行了评估。研究结果表明,在不同水平上加入RCA和部分替代FA被证明是用于结构和路面施工目的的透水混凝土的理想选择。此外,掺入10% FA和更高水平的RCA对改善透水混凝土的微观结构性能非常有益。在添加10% FA和100% RCA的混合物中,观察到C-S-H和C-H与致密分层的均匀显微照片。
{"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 Q1 Engineering Pub Date : 2023-10-03 DOI: 10.1680/jmacr.23.00037
Labeat Misini, Jelena Ristic, Viktor Hristovski, Danilo Ristic
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.
基于嵌入式销钉连接的预制n -系统广泛用于东南欧及更远地区的大型预制工业厂房,包括高地震活动性地区。为了真实地评估连接的抗震性能、安全裕度和局限性,必须进行实验研究。通过对原屋面梁柱连接大型原型模型的室内试验,得出了其实际承载能力、损伤扩展模式和特定破坏模式。然后将实验研究扩展到一个升级的屋顶梁柱连接的原型模型。为了提高安全性,连接采用了改进的混凝土约束和更强的钢连接销。实验结果清楚地表明,所实现的引脚连接升级方法的升级效果非常有限。为了获得更好和更可靠的安全升级,必须开发一种新的创新和有效的升级方法。通过广泛的分析模拟研究,证明了所实现的精细非线性三维微观建模概念能够真实地模拟经过测试的原始和升级的屋顶梁柱连接的复杂非线性响应。
{"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 Q1 Engineering Pub Date : 2023-10-01 DOI: 10.1680/jmacr.2023.75.20.1080
{"title":"Erratum","authors":"","doi":"10.1680/jmacr.2023.75.20.1080","DOIUrl":"https://doi.org/10.1680/jmacr.2023.75.20.1080","url":null,"abstract":"","PeriodicalId":18113,"journal":{"name":"Magazine of Concrete Research","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44444383","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
期刊
Magazine of Concrete Research
全部 Acc. Chem. Res. ACS Applied Bio Materials ACS Appl. Electron. Mater. ACS Appl. Energy Mater. ACS Appl. Mater. Interfaces ACS Appl. Nano Mater. ACS Appl. Polym. Mater. ACS BIOMATER-SCI ENG ACS Catal. ACS Cent. Sci. ACS Chem. Biol. ACS Chemical Health & Safety ACS Chem. Neurosci. ACS Comb. Sci. ACS Earth Space Chem. ACS Energy Lett. ACS Infect. Dis. ACS Macro Lett. ACS Mater. Lett. ACS Med. Chem. Lett. ACS Nano ACS Omega ACS Photonics ACS Sens. ACS Sustainable Chem. Eng. ACS Synth. Biol. Anal. Chem. BIOCHEMISTRY-US Bioconjugate Chem. BIOMACROMOLECULES Chem. Res. Toxicol. Chem. Rev. Chem. Mater. CRYST GROWTH DES ENERG FUEL Environ. Sci. Technol. Environ. Sci. Technol. Lett. Eur. J. Inorg. Chem. IND ENG CHEM RES Inorg. Chem. J. Agric. Food. Chem. J. Chem. Eng. Data J. Chem. Educ. J. Chem. Inf. Model. J. Chem. Theory Comput. J. Med. Chem. J. Nat. Prod. J PROTEOME RES J. Am. Chem. Soc. LANGMUIR MACROMOLECULES Mol. Pharmaceutics Nano Lett. Org. Lett. ORG PROCESS RES DEV ORGANOMETALLICS J. Org. Chem. J. Phys. Chem. J. Phys. Chem. A J. Phys. Chem. B J. Phys. Chem. C J. Phys. Chem. Lett. Analyst Anal. Methods Biomater. Sci. Catal. Sci. Technol. Chem. Commun. Chem. Soc. Rev. CHEM EDUC RES PRACT CRYSTENGCOMM Dalton Trans. Energy Environ. Sci. ENVIRON SCI-NANO ENVIRON SCI-PROC IMP ENVIRON SCI-WAT RES Faraday Discuss. Food Funct. Green Chem. Inorg. Chem. Front. Integr. Biol. J. Anal. At. Spectrom. J. Mater. Chem. A J. Mater. Chem. B J. Mater. Chem. C Lab Chip Mater. Chem. Front. Mater. Horiz. MEDCHEMCOMM Metallomics Mol. Biosyst. Mol. Syst. Des. Eng. Nanoscale Nanoscale Horiz. Nat. Prod. Rep. New J. Chem. Org. Biomol. Chem. Org. Chem. Front. PHOTOCH PHOTOBIO SCI PCCP Polym. Chem.
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
0
微信
客服QQ
Book学术公众号 扫码关注我们
反馈
×
意见反馈
请填写您的意见或建议
请填写您的手机或邮箱
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
现在去查看 取消
×
提示
确定
Book学术官方微信
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术
文献互助 智能选刊 最新文献 互助须知 联系我们:info@booksci.cn
Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。
Copyright © 2023 Book学术 All rights reserved.
ghs 京公网安备 11010802042870号 京ICP备2023020795号-1