Controlled tropical curing method for accelerated concrete strengths

Abstract

Accelerated curing and testing of concrete can be used for both quality control and quality assurance. This paper presents controlled curing and accelerated curing methods for early assessment and prediction of strength of concrete and discusses their relative merits. The controlled curing method utilises the inherent high ambient temperature of the tropics without the artificial heating needed for other accelerated curing methods. The test specimens are controlled cured for only 24 hours prior to testing. A series of compressive strength tests were conducted on concrete of varying proportions. Two types of water reducing admixtures were used individually in some mixes. A multiple linear regression technique has been adopted where appropriate to correlate the 28-day standard cured strength with the controlled cured strength, 35° cured strength, 55° cured strength and standard 2 day and 3 day strengths. The correlation results are discussed in detail. The important observations arising in this study are: the simplicity of the controlled curing method; the reliability of multiple linear regression relations; and the small effect of admixtures on the correlations between strengths. © 1989.