Concrete drying kinetics: development of an accelerated drying protocol in fire testing

Abstract

This work proposes an accelerated drying protocol that allows reaching a hydric and mechanical state representative of normal service conditions while optimizing the storage time of the specimen before the fire resistance test. The temperature and relative humidity conditions are chosen in a range where microstructure changes are insignificant. An extensive experimental campaign on four concrete formulations is performed, including drying experiments (ambient and accelerated) and fire tests with different durations depending on the type of storage (normalized vs. accelerated drying). Then, the accelerated protocol is proposed based on the modeling of drying at moderate temperature. According to the predictive study, the target moisture content could be achieved under several drying conditions, showing that ad hoc solutions can be proposed. The reproducibility of the accelerated drying protocol is essential to ensure widespread application in research and industrial laboratories. This article focuses on the assessment of the water status.