Effect of Isothermal Curing on the Compressive Strength of High EarlyStrength Concrete
Proceedings of the 2nd World Congress on Civil, Structural, and Environmental Engineering
Current utilization of high early-strength concrete has been a customary practice in majority of concrete pouring activities specifically for reinforced bulk/mass concrete foundation of structures nowadays. As a practical example, this type of concrete mix where satisfactorily employed for the concrete pouring of turbine-generator mat foundation for a coal-fired power plant somewhere in Batangas, Philippines. Technical preparations where undertaken to ensure and minimize the adverse effect on
... ss concrete such as coping up with the generation of cement heat of hydration and attendant volume change which may cause cracking. Sets of thermocouple device where directly installed to monitor and record the changes in temperature prior and after concrete pouring. It was found out from actual monitoring results that even after implementing respective adjustment on component temperature reduction of constituent concrete materials as well as the concrete mixture, the recorded temperature variation had exceeded usual threshold recommended by regular specifications and similar studies undertaken for this type of concrete. Compressive test results of cylinder samples corresponding to early-age (1, 3, 7 & 14 days) concrete strength showed notable increase in strength vis-à-vis elevated curing temperature; while ensuing 21, 28 & 56 day curing period had resulted in declining values as the isothermal temperature also normalize. As normal cured cylinder samples attain higher concrete strength as it aged, this trend were not identical and similar to the strength profile of tested isothermal cured cylinder samples, instead; a downward trending deviation in strength values were recorded. Thus this work gives us a good assessment that inherent chemical reaction and internal heat generation when not properly controlled, will adversely impact the strength of concrete samples at early and later age.