钢纤维混凝土动态抗拉强度的实验研究

Dyanmic tensile strength tests for steel fiber reinforced concrete

基于线弹性和一维应力波假定,采用Φ75mmSHPB对钢纤维体积率Vf分别为0、0.75%和1.50%的三种混凝土材料进行了一维杆层裂实验,考虑了应力波在混凝土材料内传播时的波形弥散效应和应力幅值衰减,通过计算应变片记录的应力信号确定了材料的动态抗拉强度。结果表明,钢纤维混凝土的动态抗拉强度受应变率和钢纤维体积率的影响,可为测试脆性材料的动态抗拉强度提供一种有效方法。基于微观扫描技术,对钢纤维增强机理进行了分析。

Based on assumptions of linear elastic and one-dimension stress wave,spalling tests for steel fiber reinforced concrete bars with fiber volume ratio of 0,0.75% and 1.50%,respectively were conducted by using Φ75mm SHPB,and the dynamic tensile strength was obtained by calculating the stress signals recorded with strain gauges pasted on the specimen considering wave shape dispersion and attenuation of stress waves traveling through concrete material.The results showed that the dynamic tensile strength is affected by strain rate and fiber volume ratio.Here,an effective method for testing the dynamic tensile strength of brittle material was provided.The reinforced mechanism of steel fiber was analyzed based on the micro scanning technique.