Optimum Curing Regimes of Early Strength Concrete Inclusive of Heat Transfer and Hydration Effects

Abstract

The optimum curing regime (OCR) empirically obtained from a number of small-sized specimens may be overly conservative or inaccurate due to neglecting the effects of exothermic hydration and geometries of full-sized members related to heat transfer. This study presents a theoretical model considering these effects to determine the OCRs of early strength concrete (ESC) in a Pareto set from an extensive design space. To validate the model, experiments were performed to measure the temperature histories and strength development under steam-curing conditions for a full-sized beam segment and match-cured small cylinders made of ESC. Parametric studies showed that energy savings of 7.5%, 20.4%, 42.7%, and 56.3% in steam curing could be achieved with the increase of the maximum steam temperature, sectional area, cooling period in the curing regime, and compressive strength of ESC, respectively. The most significant energy saving, 66.1%, was realized by including the favorable effects of hydration, compared with the results of OCR without hydration for the section considered in this study.