废旧瓷砖骨料再生混凝土抗冻融循环性能及可靠性分析

Freeze thaw cycling performance and reliability analysis of waste ceramic tile recycled aggregate concrete

为了研究废旧瓷砖颗粒的不同取代率对再生混凝土抗冻融循环能力的影响,设计了废旧瓷砖颗粒取代率为0,20%,40%,60%,80%,100%的6组配合比,采用快冻法对6组再生混凝土进行了冻融循环试验,分别检测混凝土质量损失率和相对动弹模量。以质量损失率、相对动弹性模量为衡量指标,评判出最优配比,采用Wiener分布概率方法建立可靠度函数以此来反映最优配比试件的剩余寿命。结果表明,在冻融循环过程中,各试件的动弹性模量呈现下降的趋势;质量损失率呈现先增加后减少的趋势。当废旧瓷砖颗粒的替代率为20%时,废旧瓷砖再生混凝土抗冻融循环能力最强,试件最快在经受398次冻融循环后才会失效;随着替代率的增加,再生混凝土的抗冻融循环能力大幅度下降。

In order to study the effect of different substitution rates of waste ceramic tile particles on the freeze-thaw cycle resistance of recycled concrete,waste ceramic tile particles with six mix ratios of 0,20%,40%,60%,80%and 100%were designed.The freeze-thaw cycles of six groups of recycled concrete were tested by quick freezing method,and the loss rate and phase of concrete quality were detected respectively.Taking the mass loss rate and the relative dynamic elastic modulus as the indexes,the optimum proportion was judged,and the reliability function was established by Wiener distribution probability method to reflect the remaining life of the optimum proportion specimens.The results show that the dynamic elastic modulus decreased during freeze-thaw cycles and the mass loss rate increased first and then decreased.When the replacement rate of waste ceramic tile particles was 20%,the recycled concrete of waste ceramic tile had the strongest freeze-thaw cycle resistance,and the fastest test specimen failed after 398 freeze-thaw cycles.With the increase of replacement rate,the freeze-thaw cycle resistance of recycled concrete decreased greatly.