Investigation the Durability Properties of Non-Air Entrained Roller Compacted Concrete Containing Coal Waste Ash against Detrimental Effects of De-Icing Salts

The aim of this study is feasibility of using Coal Waste Ash (CWA) as partial replacement of cement in non-air entrained Roller Compacted Concrete Pavement (RCCP) and evaluating its durability against deicing salts effect. In this research, 4 different mix designs were used to prepare RCC samples. The cement content equivalent to 14% by mass of dry materials was selected for control mixture without CWA. In other mixture, 2, 3 and 4% (by mass of dry materials) CWA was used. In order to evaluation the durability, chloride ion penetration, deicing salt surface scaling resistance and freeze-thaw resistance exposed to salt solution were performed. According to results, all mixture in this research obtained acceptable chloride ion penetration. The mixture with 3 and 4% CWA showed the highest and lowest chloride ion resistance respectively. By increasing CWA contents to amount of 3%, surface scaling exposed to salt solution in RCC samples delayed approximately 5 cycles. However, start of surface scaling in mixture containing 4 % CWA occurs in lower cycles compare to other sample. At the end of surface scaling test, weight changes in samples containing 2 or 3% CWA is almost the same as controls mixture. Up to 180 freeze-thaw cycles in presence of salt solution, ultrasonic pulse velocity in control mixture is higher compare to other sample. While, the reduction of this parameter is lowest for 3% CWA samples at the end of the freeze-thaw test. Based on ultrasonic pulse velocity during 300 freeze-thaw cycles, control, 2 and 3% CWA samples have excellent resistance. Mixture containing 4% CWA have excellent resistance during 180 freeze-thaw cycles. However its resistance decreased in continues. Relative dynamic modulus of elasticity during 300 freeze-thaw cycles is almost the same for control, 2 and 3% CWA samples. While this parameter for mixture containing 4% CWA reduced more than 40% at the end of freeze-thaw cycles. The durability factor at the end of freeze-thaw test, are satisfactory for control mixture and samples containing 2 and 3% CWA.