Temperature Dependence of Compressive Strength of Conversion-inhibited High Alumina Cement Concrete

The strength reduction ofhigh alumina cement (HAC) concrete due to conversion is one of the major reasons given for limiting the use of HAC in structural members. A conversion-inhibited concrete is introduced in this paper. The effect ofcuring and exposure conditions (e,g., temperature) on the compressive strength of HAC or modified HAC concretes was studied. Ground granulated blastfurnace slag (ggbs) and a conversion-preventing additive (CPA) containing natural zeolite or silica fume in combination with sodium sulfate were used to inhibit the strength reduction of the HAC concretes. The results indicated that conversion-inhibited HAC concrete containing a CPA has a one-day compressive strength greater than 55 MPa when cured at 4-5 deg C. The strength of the HAC/CPA concrete is much less ajfecred by the concrete temperature than plain HAC or HAC/ggbs concrete.