Estimation of Early-Age Tensile Stresses in Mass Concrete Containing Ground Granulated Blast Furnace Slag

Abstract

In this study, the early-age mechanical properties of a concrete mix containing ground granulated blast furnace slag (GGBFS) were investigated and incorporated in a finite-element model. The viscoelastic behavior caused by early-age tensile creep was considered using a viscoelastic analysis in which the creep strain increment was calculated using a strain superposition method. Subroutines for a FEM program (ABAQUS) were developed to predict the stress time-history considering early-age tensile and compressive creep during thermal loading and unloading. Three 1.2-m (4-ft) cubes were cast with a mix design containing 50% replacement by weight of the cement with GGBFS. The FEM predictions match well with the experimental strain measurements. The results indicate that using the proposed analysis and the measured mechanical properties obtains an accurate estimation of the maximum tensile stress for a concrete mix containing GGBFS. Engineers can use the estimated tensile stresses to take preventative measures to minimize the risk of thermal cracking on mass concrete structures.