Effect of short-term exposure to moderate temperatures on the residual strength of cracked fibre reinforced concretes

This work studies the effect of short-term exposure to temperatures -15°C, 5°C, 40°C and 60°C on flexural performance Fibre Reinforced Concretes (FRCs) with steel synthetic fibres in cracked conditions. The results will be compared conditions at 20°C (submerged air environments). content was chosen guarantee similar residual strength all mixes. beams were pre-cracked following EN 14651 ambient temperature after 28 days, up a crack mouth opening displacement (CMOD) 0.5 mm. Afterwards, these exposed for 3 days moderate temperatures, they re-loaded failure maintaining target during test. CMODs 1.5, 2.5 3.5 mm analysed. Concrete mixes also characterised by compressive strength, content, fresh density, workability. show that strengths FRC are more sensitive sub-zero than warm behaviour uncracked specimens. Synthetic FRCs presented enough response under