Reactive powder concrete reinforced with steel fibres exposed to high temperatures

Abstract

An experimental investigation was carried out to assess the mechanical properties of reactive powder concrete (RPC) reinforced with steel fibres (2% in vol.) when exposed to high temperatures. The compressive, flexural and tensile strength, modulus of elasticity and post-cracking behaviour were assessed after specimens' exposure to different high temperatures ranging from 400 to 700°C. The mechanical properties of the RPC were assessed for specimens dried for 24 hours at 60 °C and 100 °C. Partially dried specimens (60 °C) exhibited explosive spalling at nearby 450 °C, while fully dried RPC specimens (100 °C) maintained their integrity after heating exposure. In general, the mechanical properties of RPC significantly decreased with the increase of the temperature exposure. The rate of decrease with temperature of the compressive, tensile and flexural strengths, as well the corresponding post-cracking residual stresses was higher for exposure temperatures above the 400 °C.