ABSTRACT
This study was conducted to develop a cost-effective field-curing method of concrete specimens that can accurately represent the strength of an in-place concrete item. The results from this study can help concrete construction companies to improve service and assist decision-makers to determine falsework/formwork removal and road opening times. Specifically, a total of four slabs representing in-place concrete items and 52 cylindrical specimens were prepared and cured using four different curing methods. Selected specimens were also embedded with sensors for monitoring the internal temperature of concrete with time. Results showed that curing specimens in a power-operated box provided the early 1-Day strength closest to in-place concrete slabs compared to the curing methods of ambient air, insulated coolers, and insulated cylinders. The data from both the power-operated boxes and insulated coolers showed satisfactory estimations of early strengths of the in-place concrete slabs up to a 3-Day duration. Beyond the 3-Day duration, all four methods used in this study overestimated the compressive strength of in-place concrete slabs. Therefore, concrete construction can use power-operated box for decision-making on early strength because of its cost-effectiveness.
