Application Of High Macromoleclar Polymer In Concrete Surface Repair

With the rapid development of urbanization process in our country,the concrete has become one of highest rates of consumptions in building materials.However,the low surface strengths and the existence of fissure are still the problems that should be solved.Considerable researches have been done on the application of high-molecular polymer in repairing concrete surfaces by a host of scholars from domestic and foreign researchers,which were mainly concentrated on modifying a certain polymer to solve the problems that mentioned above.Whereas the comprehensive researches which based on using various polymers to increase the surface-hardness and repair the fissures are relatively few.The present project is based on Lithium-based penetrants,organic silicon compounds and epoxy resin,mixed with sodium sulfate,emulsion powder,talcum powder,film forming additives and defoamer.By testing the rebound strength of concrete,the optimal amount of concrete can be determined.Furthermore,the determination of ratio of polymer reinforcing agent can help to test the strengthening effect of the agent as well as the effects to concrete's pore structure,microstructure and durability.Based on Lithium-based penetrants,organic silicon compounds and epoxy resin,the present study also focuses on determining the patio of polymer fissure-repairing mortar through performance test and mechanical property test.The conclusions can be drawn as follows:1)Based on three polymers which mixed with sodium sulfate,emulsion powder,talcum powder,film forming additives and defoamer can enhance the surface strength of concrete.The optimal patio of polymer reinforcing agent can be determined by the rebound value of concrete surface.With the optimal patio,the increasing rate of surface strengthening for groups of Lithium-based penetrants,organic silicon compounds and epoxy resin which coat the C30 concrete for 56 days is separately approaching 14.0%,15.5% and 18.0%.2)The maximum depth of polymer reinforcing agent entering the internal of concrete is 6±0.5mm.By coating the reinforcing agent in the surface of concrete can improve the pore structure,which can also improve the densification of microstructure and the durability of concrete.3)The polymer fissure-repairing mortar has an evident repairing effect on the concrete fissure which width varies from 0.3 to 2.5mm.The optimal patio of polymer fissure-repairing mortar can be determined by mechanical property test and compatibility test.With the optimal patio,the repairing rate of concrete strength for groups of Lithium-based penetrants,organic silicon compounds and epoxy resin which coat the concrete for 28 days is 16.7%,18.2% and 22.2%.,and the insurance rate of surface strength is 84%,91% and 99%.As a whole,the polymer reinforcing agent and fissure-repairing mortar can help to solve the problems of low surface strengths and the existence of fissure in concrete.