摘要
测试了掺有3种不同规格、4种不同掺量圆直形钢纤维的超高性能混凝土(UHPC)的弹性模量、立方体抗压强度和流动性能,分析了钢纤维几何参数和掺量对UHPC弹性模量的影响。结果表明:UHPC弹性模量、抗压强度随纤维掺量的增加而增大,随纤维的长径比增大而增大;新拌UHPC的流动性能则相反。钢纤维的掺入,对UHPC弹性模量具有正、负双重效应。纤维本身较高的弹性模量,发挥着正效应;但纤维同时会降低UHPC的流动性能,增大孔隙率和内部缺陷,削弱基体弹性模量,发挥负效应;综合呈现正效应。基于试验结果,建立了考虑纤维掺量和几何参数的UHPC弹性模量的半经验预测公式。UHPC弹性模量与抗压强度具有明显的相关性,为此建立了二者关系的经验公式。最后,基于收集到的42篇文献中320个试验数据,对上述半经验和经验公式进行了验证与修正,以扩大其适用范围。
Effects of aspect ratio and volume fraction of straight steel fiber on the modulus of elasticity(MOE),compressive strength,and flowability of ultra-high-performance concrete(UHPC)were investigated.The results show that the MOE and compressive strength of UHPC increase and the flowability of the fresh UHPC decreases with the increase of fiber volume and fiber aspect ratio.Steel fiber has both positive and negative effects on the MOE of UHPC.The positive effect of steel fiber is due to the high elastic modulus of steel fiber itself.The negative effect is caused by the decrease of the MOE of UHPC matrix due to the decrease of the flowability of fresh UHPC and the increase of the porosity and the inner defects after the fibers adding into the matrix.A semi-empirical formula was proposed for predicting the MOE of the UHPC based on the experimental data,comprehensively considering the positive and negative effects of fibers.It is indicated that the MOE of the UHPC could be strongly correlated to the compressive strength.
作者
杨简
陈宝春
苏家战
YANG Jian;CHEN Baochun;SU Jiazhan(Technology Innovation and Risk Mitigation of Bridges,National Center for International Research,College of Civil Engineering,Fuzhou University,Fuzhou 350108,China)
出处
《硅酸盐学报》
EI
CAS
CSCD
北大核心
2020年第5期652-658,共7页
Journal of The Chinese Ceramic Society
基金
国家重点研发计划项目(2018YFC0705400)。
关键词
超高性能混凝土
钢纤维
弹性模量
抗压强度
估算公式
ultra-high-performance concrete
steel fiber
modulus of elasticity
compressive strength
estimation formula
作者简介
第一作者:杨简(1990-),男,博士研究生;通信作者:陈宝春(1958-),男,教授。
