Study On The Wear Resistance And Skid-resistance Performance Of Limestone Mechanism Sand Cement Concrete Pavement

With the depletion of natural sand,it is inevitable to replace natural sand with the man-made sand for cement concrete pavement.However,due to the fact that the physical and mechanical properties for the man-made sand and natural sand were overwhelmingly different,the man-made sand not only exerts effect on the physical and mechanical properties of cement concrete,but also causes many problems,such as the decoration of the road,the abrasion resistance of the road surface and the skid resistance of the road.By application of the general model of the concrete composition and the 0.45 power equalization gradation optimization method,the content of stone powder was controlled around 10%in the per unit volume;the composite grading of ore materials were optimized,the amount of cement slurry and the volume of cement was reduced,and the physical and mechanical properties of concrete was improved.According to the whole algorithm and the theory of holographic filling of cement slurry,the cement concrete composition mix design method was analyzed by the whole algorithm.Under the standardized cement concrete abrasion resistance test,it comes to the following conclusions:(1)as the sand rate increases,the abrasion of cement concrete was strengthened,and sand rate should be 0.30～0.38;(2)with the decrease of the water-cement ratio,the wearing amount of the cement concrete was reduced,and water-cement ratio should be 0.32～0.40;(3)Slightly increasing the amount of water slurry can reduce the abrasion of cement concrete;(4)it was helpful to add natural sand in the mechanism sand to improve the abrasion resistance of the cement concrete;(5)two times wiping surface helps to reduce the abrasion amount of cement concrete.Through the field test road paving,the cement concrete composition mix design method has been testified.The slump of mechanism sand cement concrete had a certain degree of loss during transportation;the hydration of cement became faster,which caused poor decoration.The fluidity could be increased by increasing the amount of the water reducing agent.By using the method of indoor accelerated loading and polishing test,the tilting friction coefficient of 0,5 million,150,000,250,000,350,000 and 450,000 accelerated polished was tested by using polyurethane casters.Having analysed and evaluated the influence of different factors on the anti-slide performance of cement concrete,it was found that the higher the sand rate was,the smaller the sliding resistance of the concrete was,and sand ratio should be 0.30~0.38;and that the smaller the water-cement ratio was,the better the anti-slide performance of the cement concrete was,and water-cement ratio should be not bigger than 0.41;and that controlling the content of stone powder and the double coupling of clay was critically significant for anti-slide performance of the mechanism sand concrete.