Performance of RHA Blended Cement Concrete under Sodium Chloride via Wetting and Drying

This paper investigates the effects of concrete containing RHA subjected to sodium chloride solution (5% NaCl) under wetting and drying cycles. Five levels of cement replacement (0%, 10%, 20%, 30% and 40% by weight) were used. The total cementitious content used was 420 kg/m3. A water/binder ratio of 0.49 was used to produce concrete having target strength of 40 MPa at the age of 28 days. The performance of blended cement concrete was evaluated using compressive strength, chloride ion-penetration and chloride penetration depths. The results showed that the RHA blended cement concrete performed better than Portland cement concrete when exposed to 5% sodium chloride solution via cyclic wetting and drying conditions. RHA can reasonably be used as a cement replacement material for the purpose of reducing the chloride ion-permeability of the concrete, which in turn will increase its durability. Generally, a RHA replacement level of 10% or 20% is sufficient to enhance resistance to sodium chloride.