Long-term strength and resistance to chemical aggressive environments of blast furnace slag, pozzolan and limestone ternary cements

Abstract

In the cement industry, the search for a less expensive binder using mineral additions from industrial by-products or natural resources has become a major concern on the one hand to compensate for the deficit in the manufacture of Portland cement and on the other hand to reduce the environmental impact linked to the massive use of Portland cement. This research aims studying the feasibility to produce ternary cement systems by replacing clinker with a binary combination of two different mineral additions. Two types of ternary cement systems were studied: type A with 65% clinker and 35% (natural pozzolan and limestone), and type B with 65% clinker and 35% (blast furnace slag and limestone), were the combination of mineral additions was 10%+25%, 17,5%+17,5%, and 25%+10%, respectively. Study of mortars (type A or B, and sand) compressive strength at the ages of 28 days, 1 year and 3 years was carried on. Resistance to chemical aggressive environments, namely sulphuric acid (H2SO4) and hydrochloric acid (HCl) solutions, was also studied after an initial 28 days curing and for six months period of immersion, by compressive strength test, weight and pH changes. The effect of aggressive environment on the internal microstructure was also studied by mercury intrusion porosimetry (MIP).