Basic creep behavior and modeling of recycled coarse and fine aggregate concrete

•FRA, CRA and w/c have a significant compounding effect on final basic creep values of RAC.•Basic creep development trend of RAC is greatly affected by FRA, CRA and w/c.•A reliable model is proposed to predict final value and development trend for basic creep of RAC. This paper aimed to experimentally investigate the influence of fine recycled aggregate (FRA) replacement ratio on the basic creep of RAC with different coarse recycled aggregate (CRA) replacement ratios and water-to-cement ratios (w/c), i.e., the compounding effect among FRA, CRA and w/c. To achieve this, fifteen groups of specimens were prepared for long-term tests to measure the final basic creep value and basic creep development trend for concretes with different FRA/CRA replacement ratios and w/c. Test results showed that the FRA, CRA and w/c had a significant compounding effect on the basic creep behavior of RAC. Based on the traditional B4 model by Bazant (2014), a new basic creep model was derived to account for all the aforementioned influences. The model was then benchmarked against all the collected test data.