Fatigue strength and failure probability of concrete made with RCA

Abstract

The paper presents results of an investigation into the flexural fatigue strength of concrete in which all the coarse natural aggregates (NA) were replaced with coarse recycled concrete aggregates (RCA). Concrete specimens containing 100% NA were also tested. The fatigue life data of concrete made with RCA and NA has been obtained by performing flexural fatigue tests on 64 beam specimens under four-point loading. In total, 48 static flexural tests were also conducted to facilitate fatigue testing. To predict the flexural fatigue strength of concrete made with RCA, the materials coefficients of fatigue strength prediction models have been estimated. The S–N–Pf curves have been generated from the fatigue test data for concrete made with RCA. Theoretical fatigue lives for concrete made with RCA have also been estimated using a single-log fatigue equation corresponding to 10% probability of failure and compared with those of concrete made with NA. The theoretical fatigue lives of concrete made with RCA have been found to be lower by 42·0% and 60·5% compared to concrete made with NA at stress levels S = 0·90 and S = 0·65, respectively.