掺三元乙丙橡胶粉水泥砂浆性能的试验研究和分析

Experimental study of the properties of cement mortar with EPDM rubber powder admixture

系统研究三元乙丙橡胶粉以20%、40%、60%、80%和100%等体积取代河砂时对新拌砂浆和硬化砂浆性能的影响程度和规律。试验结果表明,适当掺量的橡胶粉,可以改善新拌砂浆的和易性,提高硬化砂浆适应变形的能力、早期抗裂能力、抗冻融循环耐久性、抗干湿循环耐久性,降低砂浆的表观密度和导热系数。但橡胶粉的掺入也会明显降低砂浆的力学性能和增加砂浆干缩变形值,并导致橡胶粉掺量增加到一定范围时,砂浆的抗裂能力、抗冻剥蚀能力和抗干湿循环能力降低。橡胶粉砂浆性能的缺陷需要优选其他外加剂来解决。

The effects of EPDM rubber powder admixture, by replacement of river sand at equivalent volume of 20%, 40%, 60%, 80% and 100%, respectively, on the properties of fresh and hardened mortar were investigated. The experimental results demonstrated that the workability of fresh mortar could be improved when appropriate amount of rubber powder was added. The capabilities of adapting deformation, resisting cracking at early time and resisting freeze-and-thaw as well as drying-moisturizing cycle for hardened mortar were all improved. The apparent density and heat conductivity coefficient of hardened mortar were decreased, and the mechanical properties significantly reduced and drying shrinkage increased, because of the addition of rubber powder. The capabilities of resisting cracking and corroding due to freeze-thaw as well as resisting drying-moisturizing cycle were decreased when the content of rubber powder exceeded a certain range. The defects in the properties of rubber powder mortar could be resolved by selecting the other additional agents.