摘要
为更好地掌握再生砖粉超高韧性水泥基复合材料(ECC)的工作性能和力学性能,为再生砖粉ECC的研究与推广提供依据与参考,通过试验研究了不同聚乙烯醇(PVA)纤维体积掺量对再生砖粉ECC流动性能及力学性能的影响。结果表明:再生砖粉全取代石英砂会在一定程度上削弱ECC的力学性能;随着PVA纤维体积掺量在1.25%~2.0%范围内不断增加,再生砖粉ECC拌合物流动性不断下降;再生砖粉ECC抗折强度先增大后减小,纤维体积掺量为1.75%时抗折强度最大;抗压强度随纤维掺量的增加而减小,在纤维体积掺量1.5%~1.75%范围内下降幅度最为明显;压折比不断下降,材料柔韧性增加;抗弯强度、弯曲开裂挠度与极限挠度随纤维掺量的增加而增大,试件表现出更好的韧性;拉伸开裂应变与极限应变随纤维掺量的增加不断增大,拉应变硬化特征明显;再生砖粉ECC四点弯曲试验中的极限跨中挠度和单轴拉伸试验中的极限应变具有较好的线性相关关系。
In order to better grasp the working performance and mechanical properties of recycled brick powder engineered cementitious composites(ECC),and provide basis and reference for the research and promotion of recycled brick powder ECC,the effect of polyvinyl alcohol(PVA)fiber content on the flow properties and mechanical properties of recycled brick powder ECC was analyzed through experimental research.The results show that the replacement of quartz sand by recycled brick powder weakens the mechanical properties of ECC to a certain extent.In the range of 1.25%-2.0%,as the volume of fiber content increases,the fluidity of the recycled brick powder ECC mixture decreases.The flexural strength increases firstly and then decreases,and when the fiber content is 1.75%,the flexural strength is the largest.The compressive strength decreases with the increase of fiber content,and the decrease is the most obvious in the range of 1.5%-1.75%.The squeeze ratio keeps decreasing and the material flexibility increases.The bending strength,bending cracking deflection and ultimate deflection increase with the increase of fiber content,showing better toughness and ductility.The tensile cracking strain and ultimate strain continue increasing with the increase of fiber content,and the tensile strain hardening characteristics are obvious.There is a good linear correlation between the ultimate mid-span deflection in four point bending test and the ultimate strain in uniaxial tensile test of recycled brick powder ECC.
作者
元成方
王娣
李好飞
张哲
YUAN Cheng-fang;WANG Di;LI Hao-fei;ZHANG Zhe(School of Civil Engineering,Zhengzhou University,Zhengzhou 450001,Henan,China)
出处
《建筑科学与工程学报》
CAS
北大核心
2021年第5期15-25,共11页
Journal of Architecture and Civil Engineering
基金
河南省重点研发与推广专项项目(202102310255)
河南省交通运输科技计划项目(20200410)。
