THE EFFECT OF BITUMINOUS EMULSION ON THE SULFATE RESISTANCE OF CEMENT PASTES

The effect of a commercial bituminous emulsion on the sulfate resistance of ordinary portland cement pastes is investigated. The behaviour of the hardened pastes in 5\% magnesium sulfate solution is compared with that of samples containing up to 15\% by weight of the admixture as well as that of the sulfate resisting cement. The emulsion has no effect on the rate of decrease of the sulfate and magnesium ions from the exposing solution and favours the ettringite formation in hardened ordinary portland cement pastes. A concentration of 1\% increases the compressive strength of the samples but increasing concentrations accelerate their deterioration during an exposure time of six months.