Study On Pavement Concrete Frost Resistance And The New Pavement Material

Deicing salt is widely used to thaw snow in winter in northern China.It resulrs insevere cracking damage of pavement so that pavement concrete structure can not reachservice life to design.So far the freeze-deicing salt resistance of pavement concrete isnot high, mixing with mineral admixture and air-entraned agent are adopted. In order toimprove the freeze-deicing salt resistance, measures to reduce scaled mass and loss rateof dynamic elasticity modulus of concrete were studied in this paper.The freeze-deicingsalt resistance of concrete is not high; therefore study on road cementitious materialswith slag powder and cement clinker as the main components was conducted.Effect of the water-cement ratio, mineral admixture, air-entrained agent and saltconcentration on freeze-deicer scaling resistance of pavement concrete wasresearched.The results showed that the scaled mass and the loss rate of dynamicelasticity modulus decreased with the decrease of water-cement ratio; Mineraladmixture could effectively improve the freeze-deicing salt resistance; Thefreeze-deicing salt resistance of concrete with air-entrained agent improved mostobvious;Different concentration of salt leaded to different freeze-deicing saltresistance,the freeze-deicing salt damage was most severely when the concentration ofsalt was4%.Considering the technical requirements, construction requirements, economicalrequirements and other factoers of pavement concrete, to select the economicallyreasonable slag powder and cement clinker as the main raw materials.By considerationof the setting time, shrinkage rate, mortar strength of the cementitious materials, wefiltered out the pavement cement with good performance to test.The study on theperformance of pavement concrete showed that new type of concrete not only had goodflexural strength,but also could obviously reduce the scaled mass and the loss rate ofdynamic elasticity modulus in comparison with common concrete.It was obvious thatthe surface erosion situation of new type of concrete was better than that of commonconcrete.It was found that new type of concrete had better performance than commonconcrete concerning the strength and durability,and it verified the feasibility of new typeof concrete with the slag powder and cement clinker as the main components.