Compressive Strength Estimates of Adiabatically Cured Concretes Using Maturity Methods

摘要

The strength development of standard and adiabatically cured concretes was determined. The concrete mixtures had 28-day cube strengths of 30 and 50 MPa. For both strength classes, portland cement (PC) was partially replaced with fly ash (FA) and ground granulated blast-furnace slag (GGBS) at 50% and 30%, respectively. The peak adiabatic temperature was effectively reduced with GGBS addition but was only reduced with FA addition for the lower water-to-binder ratio (w/b) concrete. Considerable early age strength enhancements resulted from the adiabatic curing regime. The Nurse-Saul and Arrhenius-based maturity functions were used to estimate the increases in early age adiabatic strength. The Nurse-Saul function underestimated the effect of high early age curing temperature for all concretes, but did so to a greater extent for those with GGBS and FA, whereas the Arrhenius-based function, which allows for the consideration of an apparent activation energy, gave more-accurate estimates. Strength estimates for adiabatically cured concretes and isothermally (50 degrees C) cured mortars were also compared, and results indicated that the latter might have been affected by the detrimental effect of high curing temperatures starting from an early age. (C) 2019 American Society of Civil Engineers.