Use of ternary blend of Portland cement and two pozzolans to improve durability of high-strength concrete

This paper presents the use of ternary blend of Portland cement with two pozzolans in producing high-strength concrete. Portland Cement Type I (CT) was partially replaced with ground Bagasse Ash (BA), ground rice husk-bark ash (RB) and Fly Ash (FA) at the dosage levels of 20% and 40% by weight of binder. In addition to a single material replacement, a blend of equal weight portions of RB and FA; and BA and FA were used. Compressive strength, porosity, chloride penetration, corrosion resistance and modulus of elasticity of concretes were determined. Test results reveal that the resistance to chloride penetration of concrete improves substantially with partial replacement of CT with a blend of equal weight portion of FA and RB; or FA and BA and the improvement increases with an increase in the replacement level. The corrosion resistances of FARB and FABA concretes were better than the CT concrete or concrete with one pozzolan. The ternary blend is attractive as FA reduces the amount of the SP needed to maintain the workability and the enhanced resistance to chloride penetration is also obtained from the synergic effect between the two pozzolans.