Influence On The Structure And Corrosion Resistance To The Surface Coating Of Concrete

In real life, the durability of concrete structure has become more and more prominent. Damage include by durability is more seriously. The surface treatment of concrete can effectively protect the harmful ions into the concrete structure, improve the durability of concrete, and prolong its service life. So the concrete surface coatings are paid more and more attention. In this paper, experiment with home-made the surface film forming coating and permeable coating as material, studying on the effect of surface coating to the mechanical property and the durability of concrete structure.In this paper, the different ratio of surface film forming coating and permeable coating are experimented by orthogonal test. Water absorption, compressive strength and the chloride ion electric flux are tested respectively after surface protection. Then, confirm the optimal experimental formula. The resistance to chemical attack of concrete that dealt with the optimum proportion coating is studied. Finally form the micro research, SEM, XRD test is used to analysis the surface film forming coating and permeable coating mechanism.The optimum proportion of surface film forming coating is acrylic acid acrylamide copolymer is 2%, Styrene acrylic copolymer is 9%, Wax emulsion is 0.1%, AEO-9 is 0.1%. The optimum proportion of permeable coating is lithium silicate is 40%, KH560 is 25%, Fluorocarbon surfactant FS-3100 is 0.5%.The results show that: compared with the blank, water absorption is decreased by 34.8%, 27.9%, 27.3% and 48.8%, compressive strength is increased by 7.44%, 9.25%, 11.01% and 11.61%, chlorine ion flux decreased by 41.57%, 8.92%,44.59% and 39.37%. With the increase of curing age, concrete water absorption and deictic quantity are slightly reduce with curing age's growth, but the change rate of compressive strength is grower.The results show that: compared with quality and compressive strength of concrete is attacked into chemical corrosion solution before and after, the resistance to chemical attack of concrete, which pointed by surface coating, is increased to varying degrees. When the surface film forming coating and permeable coating are composited and pointed on the surface of concrete, the effect of resistance to chemical attack is better than others.SEM microscopic analysis shoes that, compared with the blank, the surface of concrete is level off and without a large amount of SiO₂ particles to pile up, when the concrete is coated with surface film forming coating; Internal porosity decreases, the surface permeable coating has filling and close-graining effect. Compared with the blank, XRD test shows the content of Ca?OH?₂ slightly reduces.