Laboratory and field performance of maturity functions Available to Purchase

This study compared the performance of various maturity functions based on the calculated age conversion factor, equivalent age, estimated strength and setting time of concrete mixtures using laboratory and field data. The influence of varying dosages of the particular retarder on the apparent activation energy and temperature sensitivity factor associated with the Freiesleben Hansen and Pederson, and Carino and Tank, maturity functions was found to be negligible. As expected, the influence of the apparent activation energy in the Freiesleben Hansen and Pederson function was found to depend on the deviation of average concrete temperature from the reference temperature. The performance of maturity functions depended on the temperature–time history of concrete in both laboratory and field conditions. Based on this study, calculated age conversion factors, equivalent ages and estimated strength development based on the two functions differ from those obtained using the Rastrup, Weaver–Sadgrove, and Nurse–Saul functions. All maturity functions predicted initial setting time reasonably well with varying retarder dosages and initial concrete temperature in both field and laboratory conditions.