Durability properties of non-air entrained roller compacted concrete pavement containing coal waste ash in presence of de-icing salts

The aim of this study was to evaluate the durability properties of non-air entrained roller compacted concrete pavement (RCCP) containing coal waste ash (CWA) as partial replacement of cement in presence of de-icing salts. Four different mix combinations were used to prepare RCCP specimens. In control mix with no CWA, the cement content was fixed to 14% by mass of dry aggregates. In other mixes, cement was replaced with 2, 3 and 4% CWA (by mass of dry aggregates) named as C2, C3 and C4, respectively. Durability characteristics such as permeable void content, chloride ion penetration, de-icing salt surface scaling resistance and freeze-thaw resistance exposed to salt solution were evaluated. According to results, all studied RCCPs showed acceptable chloride ion penetration. By increasing CWA content up to 3%, surface scaling exposed to salt solution delayed approximately 5 cycles. In presence of salt solution, up to 180 freeze-thaw cycles, ultrasonic pulse velocity in control mix was slightly more than C2 and C3 mixes while at higher cycles than 180 the reverse was true. C4 mix revealed excellent resistance during initial 180 freeze-thaw cycles while its resistance drastically reduced in continue and showed critical behavior up to 300 cycles. Relative dynamic modulus of elasticity during 300 freeze-thaw cycles was almost the same for the control, C2 and C3 mixes. Conversely, C4 mix experienced more than 40% dynamic modulus reduction at the end of freeze-thaw test. The durability factor at the end of freeze-thaw test was satisfactory for the control, C2 and C3 mixes. Based on the results of durability tests, the optimum CWA content was determined as equal to 3%.