The Experimental Research On Pavement Air-entrained Concrete

With the improvement of the requirement on highway service capabilities and its level, the slip-form construction technique is developing rapidly, at the same time, the requirement on concrete materials increases continually and the air entrained concrete as a cement concrete of good performance is widely applied. The air entrained concrete not only has such working performance as good water-holding capacity, viscidity and cohesion, but also a good impermeability, frost resistance and durability. Furthermore, the air entrained concrete not only saves the cost of production, improves the efficiency of production, but also improves the quality of the road surface of cement concrete to extend the life-span of the concrete road, reduce the cost of road maintenance and brings great economic and social benefit as well as protects environment and save energy sources.This thesis studies the air entrained concrete and its relevant content along with the reconstruction project of Qinglian arterial highway by the cement slurry static test method,pressure method hybrid gas detector law,kim jong-pressure water detector law, flat-panel cracking test methods and etc.The research results show that: the gas content of concrete increases with the increasing of admixtures dosage, and the degree of increment is related to the components of admixture; the compound use of water reducing admixture and air entraining agent can arrive at the best modified effect of concrete; the bleeding rate of concrete decreases with the increasing of gas content and gradually slows down to zero, and the anti-bleeding properties of the air entrained concrete is good; the increasing of gas content is in favor of improving the sensitivity of cracking of concrete and is beneficial to improvement of the early anti-cracking performance of concrete; the increasing of gas content is in favor of reducing the deformation of concrete, slowing down the deformation concrete, and when gas content less than 6 percent, the deformation rate will reduce with the gas content increases, while greater than 6 percent, the deformation rate may increase with the gas content increases; the thermal conductivity of concrete and its thermal diffusivity reduces with the increasing of the gas content within a certain range of gas content changes; early conservation is very effective in reducing concrete cracking , and the effect will be better with conservation agents and better methods of conservation. This paper also analyzes the operation mechanism of the anti-bleeding properties and the anti-cracking performance of the air entrained concrete. The research in this thesis achieved good results in practical applications,while provided a scientific basis and a good guide for the use of air-entraining concrete on the pavement of Qinglian arterial highway project.