冻融作用下玻化微珠保温混凝土的劈裂抗拉性能试验

在保温混凝土优化配合比的基础上,选定水灰比、水泥用量、砂率和外加剂掺量四个影响因素,设计正交试验,采用快冻法对混凝土进行0、15、30、50次冻融循环,观察各组试件表面剥蚀情况,确定混凝土强度及其退化特征。试验结果表明,0.50为最佳水灰比,经过50次冻融循环作用后,强度下降为初始值的66.7%。建立了冻融后保温混凝土劈裂抗拉强度值与冻融循环次数之间线性函数关系,并通过极差分析确定了水灰比是影响混凝土冻融后强度的主要因素。

Experimental study on tensile splitting strength of glazed hollow beads thermal insulation concrete under freeze-thaw cycles

Based on the optimum mixture ratio of the thermal insulation concrete,the orthogonal tests have been designed choo-sing four main factors,i.e.,water-cement ratio,cement content,sand ratio and dosage of admixture,which influence the ther-mal insulation concrete strength.Glazed hollow beads thermal insulation concrete has been conducted 0,15,30,and 50 times of freeze-thaw cycles by the method of quick freezing.Then each specimen surface erosion situation is observed and the concrete strength and its degradation characteristics are determined.Test results show that the best water-cement ratio is 0.50 with which concrete strength decreases to 66.7% of initial value after 50 freeze-thaw cycles.Then,the linear regression equation is estab-lished with a view to tensile splitting strength and freezing and thawing cycle times.It is concluded by range analysis that water cement ratio is the main factors influencing the strength of concrete after freeze-thaw.