Prediction of Early Age Normal Concrete Compressive Strength Based on Dynamic Shear Modulus Measurements

Abstract

In this research, the relationship between the compressive strength, fc, and the dynamic shear modulus, Gd, of normal concrete at an early age was studied. To investigate the correlation between fc and Gd at an early age, different types of mixtures, including mortar and concrete, were prepared, and the corresponding fc and Gd values were measured every 12 h after initial mixing up to 72 h after casting. The influences of hydration age, water-to-cement (w/c) ratio, curing temperature, aggregate volume content, and maximum aggregate size on the Gd−fc relationship of concrete were studied. The Gd−fc relationship was then mathematically modeled by using multivariable power laws. The developed model is reasonably accurate to predict the early age compressive strength of concrete with variations in hydration age, aggregate content, and sizes. This type of model can be used directly in the field for the estimation of concrete strength when nondestructive testing (NDT) techniques are employed.