Study On Mixtures Optimization And Construction Temperature Control Of Asphalt Conctete Face Slab Of Hohhot Pumped-storage Power Station

Asphalt concrete,with the advantages of anti-seepage and deformation functions,which becomes the first choice of the face slab material of earth-rockfill dam or reservoir seepage control structure.Asphalt concrete is a kind of viscoelastic material,so it presents viscoplasticity at high temperature but brittleness at low temperature.Asphalt concrete face slab(ACFS)directly contacts with the atmosphere in a cold area,so the internal temperature changes gradiently,and the thermal stress has uneven distribution in the direction along the slab thickness.ACFS may have cracks if the temperature stress is stronger than the designed material tensile strength.For Inner Mongolia Hohhot pumped-storage power station was build in a cold region,to study the mixture proportion and construction technologies of asphalt concrete is very meaningful to improve construction quality of the dam face slab.In this paper,according to the actual climatic conditions at the jobsite,as well as the design standards,several mixture proportion tests were made to select the optimal proportion of each layer of asphalt concrete face slab.With comparative trails,the temperature ranges were determined for the processes of mixturing,transportation,pavement and rolling,respectively,thus resulting in improving the temperature control of asphalt concrete construction in the area with low temperature.Using the optimal mix proportion and construction temperatures which were verified through in-situ tests,the construction quality was improved significantly,and the difficulties of asphalt concrete face slab construction in cold region were conquered successfully.