SFRC exposed to high temperature: Hot vs. residual characterization for thin walled elements

An experimental investigation based on unnotched four point bending tests is here presented. It aims to check the high temperature resistance of thin slabs made of steel fiber reinforced concrete (SFRC). The application of fire recommendations to SFRC structures requires knowledge of the tensile strength decrease due to high temperature exposure. Very few data are available in the literature, but useful information could be obtained in “residual” conditions, i.e. by testing the specimen at room temperature after a suitable thermal cycle. The paper discusses the influence of the testing conditions (hot vs. residual) on the tensile mechanical behavior of the material, the evaluation of self-stresses induced in the samples by the test procedure adopted and the variation of post-cracking tensile properties at SLS and ULS according to the design approach proposed by Model Code 2010.