Research On Application Of Waste Tire Rubber Particles In Plaster Mortar

The waste rubber tire of crushing into granular is added into the concrete or mortar,which not only can reduce the harm of the “black pollution”, but also can improve theperformance of concrete or mortar. Studies show that adding rubber particles canimprove the fracture toughness and impact resistance of concrete materials, and alsohave a certain impact on air content, strength, thermal insulation, sound insulation, etc.However, rubber is organic polymer material, the interfacial bonding properties betweenthe cement-based materials is poor. Therefore, how to modify the surface of the rubberparticles and improve the interface compatibility on the surface of the rubber particlesand cement-based materials, become the key technical problems on good application ofthe rubber particles in cement-based materials.This paper select the rubber particles in three different size (the20mesh,40meshand60mesh), add the rubber particles after modification which is modified by thesodium hydroxide (NaOH) saturated solution, carbon tetrachloride (CCl4) solution,1%polyvinyl alcohol (PVA) solution and silane coupling agent (KH-550,KH-560KH-570)to the cement mortar in accordance with certain content and study the effect ofrubber particles on strength, impact resistance, tensile bond performance of cementmortar. On this basis, determine the appropriate rubber particle size and content in avariety of modification methods.The experimental results show that40mesh rubber particles is the optimum size ofthe test, the modification effect of the sodium hydroxide (NaOH) saturated solution,1%polyvinyl alcohol (PVA) solution and2%silane coupling agent KH-550are better andthe optimal content of40mesh rubber particles ranges from15%to25%. On this basis,the orthogonal experiment is carried out in line with the ratio of the plaster mortar nowsold on the market. Then the optimum mixture ratio of the plaster mortar which mixedwith the modified rubber particles is gained, that is m(C)：m(S)：m(RP)：m(VAC/VeoVa/E)：m(HPMC)=1:1.875:0.164:0.028:0.004.Crack test shows that rubber particles after the modification can obviously improvethe plastic shrinkage performance of mortar, the crack width reduce by59.3%comparing with the unmodified. Microscopic structure analysis shows that, rubberparticles after the modification can effectively increase the interface connection between rubber particles and cement base material, in which chemical bond is formed betweencement hydration products and the surface of rubber particles modified by couplingagent KH-550, thereby the whole strength of the crumb rubber mortar is improved.Final results show that plaster mortar of doping with modified rubber particles bybest fit preparation have good toughness, impact resistance, crack resistance andadhesive strength. The rubber particles after modification can completely replace thefiber component of plaster mortar on the market, which can cost savings, environmentalprotection, waste utilization at the same time, also can give full play to the additionalperformance of the rubber particles in the wall.