不同龄期橡胶混凝土力学性能试验研究

Experimental study on mechanical properties of rubber concrete with different curing age

为了深入研究橡胶混凝土的力学性能,以C50混凝土配合比为基准,将粒径为1~3 mm的橡胶颗粒按照5%、7.5%、10%、12.5%、15%的比例等体积取代砂,配制橡胶混凝土。研究了龄期以及橡胶颗粒掺量对橡胶混凝土基本力学性能的影响,并采用环境扫描电子显微镜对混凝土基体和橡胶颗粒与基体的界面进行分析。结果表明,随着水泥水化龄期的发展,水泥水化产物会逐渐填充密实橡胶颗粒与水泥基体之间的界面过渡区,从而实现橡胶颗粒和混凝土基体相容;掺入橡胶颗粒会改善混凝土的弹性,同时又损失了混凝土的强度,但橡胶混凝土应用于路面工程,仍然可以满足强度要求。通过对试验结果进行拟合,得到了可供预测橡胶混凝土强度的公式,也可为橡胶混凝土在路面工程中的应用提供参考。

In order to investigate the mechanical properties of rubber concrete, specimens of rubber concrete were prepared based on the ordinary concrete with strength of C50, in which the sand was replaced by rubber particles at the ratio of 5%, 7.5%, 10%, 12.5% and 15%, respectively.The influence of curing age and rubber particles proportion on mechanism of rubber concrete was studied.Micro-structures of matrix and the interfacial transition zone （ITZ） between rubber particle and matrix were also analyzed by ESEM.The test results indicate that rubber particles and matrix can be compatible, because the hydrated products will fill in ITZ with curing age increasing.Mixed with rubber particles in concrete,the concrete elasticity can be improved but concrete strength decreased.However,the concrete strength was accepted if it is used in pavement engineering.After fitting the test data, a series of formulas was given to predict the rubber concrete strength at different curing age.It can be a reference of rubber concrete application in pavement engineering.