Mechanical properties and uniaxial compressive stress-strain behavior of fully recycled aggregate concrete

This paper proposed fully recycled aggregate concrete (FRAC), which was prepared by completely replacing natural aggregates (NA) with recycled coarse and fine aggregates (RCA and RFA) and partially replacing cement with recycled powder (RP). Four different aggregate systems (i.e., full-NA, full-RCA, full-RFA and full-RAs) and three different contents of the RP (i.e., 10%, 20% and 30% of the total binder) were taken as parameter variables. The mechanical properties (compressive and tensile strength) and uniaxial compressive stress-strain relationship of FRAC were investigated. The experimental results show that the addition of recycled materials has an adverse effect on the concrete strength. Incorporating RAs or RP has little effect on the ascending branch of the normalized stress-strain curves, but the former makes the descending branch of the curves steeper, while the latter makes them flatter. The elastic modulus is reduced due to the incorporation of RAs and RP. Based on the test results, an empirical stress-strain model was proposed and discussed.

Automated summary

This study proposes a fully recycled aggregate concrete (FRAC) prepared by replacing natural aggregates and partially replacing cement with recycled materials. The addition of recycled materials has a negative effect on concrete strength and shows little effect on the ascending branch of stress-strain curves but influences the descending branch. The elastic modulus decreases due to the incorporation of recycled aggregates and recycled powder.