Influences of Chemical Composition and Fineness on the Development of Concrete Strength by Curing Conditions

In this study, the influences of chemical composition and fineness on the development of concrete strength by curing conditions were investigated through performance evaluation of high SO(3) Portland cement (HSPC) and ordinary Portland cement (OPC). At the same fineness (3800 cm(2)/g), the initial and final setting times of HSPC were 92 and 98 min less than OPC. Early mortar compressive strength was approximately 176% higher after 24 h. After curing for 15 h, 18 h, and 24 h, the maturity of HSPC concrete (107.4%, 109.6%, and 111.7%) and early compressive strength (146.4%, 170.7%, and 154.5%) were higher than measured for OPC concrete. HSPC fineness was 111.8% higher than OPC, leading to early activation of the hydration reaction. By X-ray fluorescence analysis, the SO(3) content of HSPC was 107.9% that of OPC. The applicable time for HSPC concrete form removal was shorter than that for OPC concrete. The relationships y = −10.57 ln(x) + 47.30 and y = −9.84 ln(x) + 44.05 were estimated for predicting the early-age strength OPC and HSPC concrete. Therefore, applying HSPC concrete to an actual construction site is expected to shorten the construction period and reduce the heating curing cost in winter compared to OPC concrete.