改性橡胶砂浆的物理力学性能

Physical and Mechanical Performance of Modified Rubberized Mortar

鉴于橡胶颗粒的掺加会导致橡胶砂浆的密度、抗折、抗压强度等物理力学性能降低,为改善橡胶砂浆的力学性能,使用多种硅烷偶联剂的复配液、聚合物及硅灰分别对橡胶砂浆进行改性研究。试验结果表明,对于相同橡胶掺量的砂浆,硅烷偶联剂复配液、聚合物及硅灰的添加提高了橡胶砂浆的各项力学性能。变形试验结果表明,聚合物的掺加增加了砂浆的韧性,改善了橡胶与水泥水化物的界面粘结。耐磨性试验结果表明,低掺量的橡胶颗粒对砂浆耐磨性能影响可能不大,橡胶砂浆仍可保持较好的耐磨性。橡胶颗粒与水泥石界面存在明显空隙,是橡胶砂浆强度下降的主要原因之一。

The density, flexural strength, compressive strength of rubberized mortar will be decreased due to augment of rubber particles volume fraction of mortar. In order to enhance the performance of rubberized mortar, the modified effects of mixed liquor composed of several kinds of silane coupling agent, hydrodynamic dispersion polymer and silica fume were studied respectively. The experiment results show that three modifying agents improved the mechanical properties of rubberized mortar when the volume fraction of rubber particles in modified rubberized mortar was the same. The result of deflection test shows that the toughness of rubberized mortar was enhanced because of increase of the interface bonding between cement paste and rubber particles. The abrasion test of rubber mortar shows that low content of rubber particles may only slightly reduce the abrasion of rubberized mortar, the favourable abrasion resistance of rubber mortar still can be reserved. The interface of rubber particle and hardened cement paste has obvious gap, which is the one of main causes resulting in reduce of the strength of rubberized mortar.