不同取代率再生混凝土抗压强度尺寸效应研究

Study on size effect of compressive strength of recycled concrete with different substitution rates

采用5种不同取代率(0、25%、50%、75%和100%)和3种不同边长(70 mm、100 mm和150 mm)再生混凝土立方体试件,研究不同取代率再生混凝土抗压强度受尺寸效应影响的规律。结果表明:相同取代率再生混凝土受压破坏机理均相同,不受尺寸效应和再生料取代率影响;不同取代率再生混凝土抗压强度存在明显的尺寸效应,尺寸越大其抗压强度越低,再生骨料取代率越高尺寸效应影响越低。建立了不同取代率再生混凝土尺寸效应计算公式。

In order to explore the size effect of compressive strength of recycled concrete with different substitution rates,recycled concrete cube specimens with five different replacement rates(0,25%,50%,75% and 100%) and three kinds of edge length (70 mm,100 mm and 150 mm) were tested. The results show that the compression failure mechanism of the recycled concrete with the same substitution rate is the same,it is not affected by the size effect and the regenerative ratio of reclaimed material;The compressive strength of recycled concrete with different substitution rate is obviously influenced by the size effect. The larger the size,the lower the compressive strength. The higher the substitution rate of recycled aggregate,the lower the effect of size effect. A formula for calculating the size effect law of recycled concrete with different substitution rates is established.