Resistance of concrete containing ternary cementitious blends to chloride attack and carbonation
Md Jamir Anwar, Dina A. Emarah
Abstract
The resistance of concrete containing by-products materials to the combined influence of carbonation and chloride ingress has been studied. The fly ash (FA) and silica fume (SF) as by-products materials were used with ordinary Portland cement (OPC) in ternary cementitious system. Group of concrete mixes with water/cementitious blends materials ratio of 0.4 and have the same degree of workability and air content were investigated. Fresh concrete and hardened properties were measured. The concrete specimens were cured in water for 28 days, then they exposed to three stages of different environments. In stage I, samples immersed in artificial sea water for 5 months while in stage II, they exposed to 20 °C + 60% RH + 5% CO2 for 18 weeks. In stage III, samples exposed to 20 °C + 60% RH for 18 weeks. After immersing and exposing periods, the contents of soluble and total were determined using the titration analysis. The results showed improvement in the studied concrete properties due to using by-product cementitious materials and indicated a significant resistance to ingress of the chloride ions. Further, for all stages the results of cementitious blends mixes showed lower percent of soluble/total chloride than the control mix.