TEMPERATURE-DEPENDENCE OF COMPRESSIVE STRENGTH OF CONVERSION-INHIBITED HIGH-ALUMINA CEMENT CONCRETE

The strength reduction of high alumina cement (HAC) concrete due to co nversion 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 of curing and exposure conditions (e.g., tem perature) on the compressive strength of HAC or modified HAC concretes was studied. Ground granulated blastfurnace slag (ggbs) and a convers ion-preventing additive (CPA) containing natural zeolite or silica fum e 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 str ength greater than 55 MPa when cured at 4-5 deg C. The strength of the HAC/CPA concrete is much less affected by the concrete temperature th an plain HAC or HAC/ggbs concrete.