Probabilistic fatigue modelling of concrete materials incorporating recycled tyre rubber under flexural loadings

This paper presents a series of experimental investigations into the flexural fatigue performance of rubberised concrete (RuC). A detailed account of fatigue response of reference conventional concrete materials (CCM) and RuC under flexural loading is presented. The experimental arrangement is described as well as the constituent materials, and the volumetric rubber replacement ratio of both fine and coarse aggregates varies between 0 % and 20 % in this study. The effect of three different stress ratios (R = 0.1, 0.3 and 0.5) on the flexural fatigue response are studied. It is found the static flexural strength of RuC with the rubber contents (ρ_rv) of 10 % and 20 % show a reduction of 12 % and 24 % compared to their counterpart of CCM, respectively. A stress level of 0.9 is embedded in this study while despite the uncertainty of fatigue life of concrete materials, the increase of stress ratio from 0.1 to 0.5 lead to an increase of fatigue life of RuC in general. It is notable that the inclusion of rubber in concrete increases the fatigue life uncertainty whereas significantly increases the fatigue life of RuC at the same time, i.e. the average fatigue life of RuC with 20 % rubber content shows an increase of 170 % compared to its counterpart of CCM when R = 0.5. Based on the experimental results in this study, a series of three-parameter Weibull distribution models are proposed to describe the failure probability of RuC under fatigue flexural loadings, which consider the effects of ρ_rv, stress ratio, stress level, and loading frequency on the probability of failure (PF) of RuC. This paper presents the attempt to investigate the possibility distribution of fatigue life of RuC, and all numerical calculation curves are in good agreement with the experimental results carried out in this study.