Mechanical properties and fatigue analysis of rubber concrete under uniaxial compression modified by a combination of mineral admixture

To understand rubber concrete's mechanical and fatigue performance under uniaxial compression, a 0 %, 8 %, 15 %, 20 %, and 25 % rubber particle incorporated mineral admixture, combined with 0 %, 4 %, 8 % and 15 % fly ash (FA) and 0 %, 5 %, 10 % and 15 % silica fume (SF), was used to prepare rubber concrete. Mechanical performance and uniaxial compression fatigue tests under constant amplitude cyclic loading were conducted. A damage model for rubber concrete fatigue strain was developed based on Miner's cumulative damage theory. A reliability analysis of the fatigue life of rubber concrete was conducted using probabilistic statistical methods and experimental data. The distribution characteristics under uniaxial compression with constant amplitude cyclic loading were determined. The results indicate that rubber concrete incorporated with mineral admixture exhibits a significantly longer fatigue life compared to ordinary cement concrete under the same stress levels. Including 8 % fly ash (FA), 10 % silica fume (SF), and 15 % crumb rubber (CR) enhanced the mechanical properties of the concrete, leading to a 7.5 % increase in fatigue life. The incorporation of rubber particles also reduces the range of changes in stress strength factors. The evolution of fatigue strain in rubber concrete follows a three-stage pattern similar to that of conventional concrete, and its fatigue life is consistent with a logarithmic normal distribution. The equation for fatigue strain and damage amount of rubber concrete suggests that adding rubber may increase the fatigue deformation capacity of concrete to some extent, with the degree of improvement being independent of stress level.