Evaluation of Semi-Adiabatic Calorimetry to Quantify Concrete Setting

Abstract

Although setting is routinely measured in practice, current methods for determining concrete setting have been criticized for being impractical, arbitrary, and lacking correlation to field data. In recent years attempts have been made to develop an alternate method for quantifying concrete setting based on semi-adiabatic calorimetry results during the hydration of a concrete sample. In this study, methods to estimate concrete setting times based on data obtained from thermal testing were examined and compared to currently accepted penetration resistance-based test results. Maturity concepts were applied throughout the study to allow accurate comparisons between methods and to allow for a better correlation to in-place concrete measurements. It was found that set times that compare to those obtained as per ASTM C 403 can be accurately obtained through semi-adiabatic calorimetry. Initial and final set times were determined to occur at pre-defined adiabatic temperature rises, and a method for the calculation of these times is presented.