全再生废砖骨料混凝土导热系数试验分析与预测

以3种不同的再生废砖粗骨料替代率(40%、70%、100%)和再生废砖细骨料替代率(40%、70%、100%)设计7组试验,对再生废砖骨料混凝土导热系数进行试验和分析。试验结果表明:提高再生废砖粗骨料替代率可降低再生废砖骨料混凝土导热系数;在再生废砖粗骨料替代率为100%的基础上,增加再生废砖细骨料的替代率,则再生混凝土导热系数持续下降,其中全再生废砖骨料混凝土导热系数最低,相比普通混凝土降低幅度为57.52%;定义了再生废砖骨料影响系数G,G值越大,再生混凝土导热系数越低;研究了再生砖骨料混凝土导热系数的变化机理,在Hasselman-Johnson模型基础上,提出了再生废砖骨料混凝土导热系数修正公式,计算预测值与试验值吻合良好。

Experimental study and prediction of thermal conductivity of recycled waste brick aggregate concrete

Seven groups of tests were designed to test and analyze the thermal conductivity of recycled waste brick aggregate concrete with three different replacement rates of recycled waste brick coarse aggregate(40%,70%,100%)and recycled waste brick fine aggregate(40%,70%,100%).The results show that increasing the replacement rate of recycled waste brick coarse aggregate can reduce the thermal conductivity of recycled waste brick aggregate concrete.On the basis of 100%replacement rate of recycled waste brick coarse aggregate,increasing the replacement rate of recycled waste brick fine aggregate,the thermal conductivity of recycled concrete will continue to decline,among which the thermal conductivity of fully recycled waste brick aggregate concrete is the lowest,which is 57.52%lower than that of ordinary concrete.By defining the recycled waste brick aggregate impact factor G,the greater the G is,the lower the thermal conductivity of recycled concrete is.The thermal conductivity of recycled brick aggregate concrete is studied,based on the Hasselman Johnson model,then the thermal conductivity correction formula of recycled waste brick aggregate concrete is proposed,which is in good agreement with the test value.