Experimental Study On Modification And Thermal Conductivity Of Rubberized Mortar

With the rapid development of the automotive industry, the processing of waste tire crumb rubber has become increasingly the focus of attention. Waste tire rubber powder can not only improve impact toughness, crack resistance, frost resistance and carbonation resistance of the cement-based materials, but improve the sound insulation insulation properties of cement-based materials. The application in cement-based materials is becoming one of the effective recycling ways of waste tire rubber powder.In this paper, the research work was mainly on the effect of fineness and dosage of waste crumb rubber on the strength and thermal conductivity of cement mortar. With the increasing of rubber content, the compressive and flexural strength of mortar decreased in different degrees. Modification methods such as using NaOH solution, adding silica fume instead of partial cement as well as milling crumb rubber with silane coupling agent (mechano chemical method) were used. The results showed that:(1) The compressive and flexural strength reduced with the increasing of dosage of crumb rubber, but turned higher for the specimens with coarse crumb rubber. (2) The strength of mortar was improved by the modifying methods, immersing the crumb rubber in NaOH solution and mixing silica fume partially instead of the cement(3) After mechano-chemical modification, the strength of rubber mortar showed a of increasing first and then decreasing with the dosage increasing of coupling agent, which was higher than those only with coupling agent but no ball milling. In the meantime, ball milling time has little effect on the strength of mortar.(4) Four kinds of waste tire crumb rubber with different fineness were used to partially replace fine aggregate in mortar specimens. The thermal conductivity of rubberized mortar with four kinds of waste tire crumb rubber were separately tested. It indicated, with increasing dosage of crumb rubber, the heat-conduct coefficient of rubberized mortar decreased and the thermal insulation performance was improved.