Research On The Microstructure And Performance Of Rubber Cement Motar

The defects of portland cement concrete pavement performance severely limits its popularization and application, the related research of modified cement mortar becomes an important topic. Rubber cement concrete is one of the modified cement concretes.But the rubber powder has some influence on the strength and shrinkage resistance performance of rubber cement concrete and cement mortar, embodied in the decline of its compressive strength and the enhancement of its shrinkage resistance performance.This paper, by using X-ray diffraction test and mercury injection test technique, did some research about the modification mechanism of rubber and the microstructure of the rubber cement mortar.analysis the phases of the rubber cement hydration products,the reaction rate of cement hydration reaction and the distribution characteristics of inner pore of rubber cement mortar. The results show that the mixed rubber particles will not lead the cement hydration reaction to generate new phase structures, but the rubber particles can slow down the rate of hydration reaction.Also, rubber particles increase the cement mortar porosity, the ratio of micro-hole decrease and that of macropore increase and the overall pore size gets bigger.Also, this article tried to add a certain amount of rubber aggregate modified mortar polymer and coupling agent as additive, studies two kinds of modifier to join after the rubber aggregate of cement mortar compressive strength and flexural strength of the change rule, and using the XRD test study on two kinds of material effect on the cement hydration reaction rate.Research results show that the compressive strength and flexural strength of polymer rubber cement mortar decreases obviously as the dosage of polymer increases and coupling agent have a very significant influence in increasing compressive strength and flexural strength.Both will not lead the cement hydration reaction to generate new phase structures, but they may affect cement hydration reaction rate.The results also show that adding a certain mount of polymer and coupling agent into rubber cement mortar simultaneously can not only improve its compressive strength and flexural strength, but also can improve its shrinkage resistance performance and reduce its early shrinkage.