Research Of The Durability Effect Of Several Protectants Applied During The Formation Of Fair-faced Concrete

Concrete has become the dominant building material in the world because of its special natures of being readily obtained and easily prepared for exceeding performance in the technology of construction today.However,due to the characteristics of concrete material itself,the environmental factors and a variety of construction techniques applied,there are serious durability problems in the constructions by this material.In this study,with concrete being the constant primary material,chief protective agents obtained from the market such as acrylic,silicone,and fluorocarbons were selected and applied to the fair-faced concrete.Their durability effects on the concrete structures were each tested and evaluated.The water absorption rate test on the concrete showed that top-coating of the water-repellent agent produced greater waterproofing ability than the primer,with the best result obtained by two layers of each of primer-and top-coating.The anti-carbonization test of the concrete showed that topcoat of protective agent applied to the fair-faced concrete is better effective than the primer.When the increasing layers of the protective agent were applied,the anti-carbonization ability of the concrete accordingly improved,while fluorocarbon protective agent applied to the system achieved the best effect.In the concrete freeze-thaw cycle test,the anti-freezing ability from the top coating of protective agent was higher than that of the primer.With the increasing coating layers of the protective agent,the anti-freezing ability of the concrete sample was accordingly improved,and the silicone and fluorocarbon agents performed best.The topcoating of protective agent in the water-concrete system had better resistance to the chloride ion penetration than the primer,and the best result achieved with two layers of each of top and primer coating,with the silicone and fluorocarbon agentscontributing the best resistance to chloride penetration.In the resistance test to the sulfate erosion,the top coating again made the concrete more resistant than the primer coating,and the best resistance was also achieved when both primer and top were applied with two layers.The difference in resistance to sulfate attack among the three protectors applied was not significant.To summerize,all protective agents tested in the water-concrete effectively improved the durability of steel-reinforced concrete structures.The next step should be addressing the high cost concern of the protectants.Pertinent improvement to the issue would broader their application in the future.