| For the defects of traditional cementitious materials,just as high rigidity,brittle failure mode and cracking easily after used,this paper intends to modify the cementitious materials with most commonly used crumb rubber and polymer.After a series of experience, we explore a new kind of directly wiping materials with high adhesive strength, high durability,known as polymer and crumb rubber modified cementitious (PRMC) materials. Having 50 MPa compressive strength(28d), It can effectively prevent the cracking generation and chloride ion penetration.Also the other performances meet "the application and technical regulations for the dry-mixed mortar ". It can be widely used in wall finishing, structural repairing, inorganic material interface bonding and other occasions.The main job of this project is to explore polymer and crumb rubber modified cementitious (PRMC) materials.In the research methods ,We firstly made a large number of experiments to analysis the effect of cement amount ,cement-sand ratio and water-cement ratio on the materials performances.And then we mixed crumb rubber and polymer in turn , analysising its effects on materials performances by compression and bending test. Finally, by evaluation,using compressive strength as control index,we identified two groups of mix proportion with reasonable fluidity and excellent engineering performance. Its technical features is more superior than the common polymer modified materials in engineering performance. Aditionally,due to the lower price of crumb rubber than polymer, another feature of this material is to reduce the using amount of polymer, which will be more competitive than the common polymer modified cement (PMC) materials in price.Using many methods,this paper also study the bonding properties,drying shrinkage and resistance to chloride ion penetration of PRMC wiping materials. The results prove that PRMC material can meet the intended project objectives. Its bond strength, drying shrinkage, chloride permeability and many other engineering performance are more excellent than the common polymer modified cement materials. |
