Title: Compatible Datum Temperature and Activation Energy for Concrete Maturity

Author(s): Chang Hoon Lee and Kenneth C. Hover

Publication: Materials Journal

Volume: 113

Issue: 2

Appears on pages(s): 197-206

Keywords: activation energy; concrete strength; datum temperature; mathematical modeling; maturity; physical chemistry; temperature effects

DOI: 10.14359/51688639

Date: 3/1/2016

Abstract:
Maturity methods are used to predict strength or other mechanical properties of a concrete mixture for a given moisture availability as a function of time and temperature. Temperature sensitivity of a mixture is characterized by datum temperature for the Nurse-Saul (NS) method, and by activation energy for the Freiesleben-Hansen and Pederson method (FHP). While these methods and their defining parameters were independently developed, the parameters are nevertheless interdependent, as a change in a concrete mixture that affects temperature sensitivity as expressed by datum temperature will also be reflected in a change of activation energy, and vice versa. This paper addresses the temperature- and mixturedependent relationship between datum temperature and activation energy, using both a closed-form equation based on chemical kinetics and experimental data where values of datum temperature and activation energy were found to provide the best fit to strength data. Best-fit results validate the closed-form solution.