Investigation of the static constitutive relationship of rubberized self-compacting concrete after high-temperature exposure

Abstract

Rubber self-compacting concrete (RSCC), recognized as an environmentally friendly material, possesses excellent resistance to impact. However, the inclusion of rubber particles significantly decreases its compressive strength. This study investigated the compressive properties of RSCC with rubber particles substituting for fine aggregate volume percentages of 0 %, 10 %, 20 %, and 30 % after exposure at 25, 300, 600, and 900 °C for 3 h. The interface conditions among the rubber particles and the mortar were examined using scanning electron microscopy (SEM). The findings reveal that: (1) Both the compressive strength and the modulus of elasticity of RSCC exhibit a pronounced decline as the exposure elevates, with the maximum reduction reaching 84.25 % and 89.42 % respectively (where the substitution percentage of rubber particles is 30 %), compared to values at room temperature. Conversely, the peak strain exhibited an increase of 130.41 % (with the substitution percentage of rubber particles being 30 %). (2) As the substitution percentage of rubber particles increases, the decline in RSCC's compressive strength and elastic modulus after cooling at elevated temperatures is less noticeable than at room temperature, and the peak strain of RSCC exhibits negligible increase after being subjected to high temperatures. (3) Prediction equations and constitutive models for the compressive strength and peak strain of RSCC post-high temperature exposure are proposed in light of the experimental data. The comparison shows an obvious connection between the experimental outcomes and the predictive results.