Compressive Strength Estimates of Adiabatically Cured Concretes Using Maturity Methods

Abstract

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°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.