Uni-axial compressive stress-strain relation of recycled coarse aggregate concrete after freezing and thawing cycles

- The complete compressive stress-strain curves of RAC after freezing and thawing cycles were measured in this study.
- Theoretic stress-strain curve of RAC after freezing and thawing cycles was presented.
- Parameters of descending branch in stress-strain curve of RAC were given after freezing and thawing cycles.

The mass loss, compressive strength, dynamic elastic modulus and stress-strain relationship of recycled coarse aggregate concrete under different cycles of freezing and thawing were investigated by comparison with normal concrete in the research reported in this paper. Forty-eight prism specimens with the size of 100 mm × 100 mm × 300 mm and ninety-six cubic specimens with the size of 100 mm × 100 mm × 100 mm were fabricated and tested. Test results show that, the mass loss of recycled coarse aggregate concrete decreased first then increased with the increase of freezing and thawing cycles; the relative cubic compressive strength and the relative dynamic elastic modulus of recycled aggregate coarse concrete decreased linearly with the increase of freezing and thawing cycles. The stress-strain curve of recycled aggregate concrete first ascended rapidly and then descended rapidly after exceeding the peak stress till to 1.5 times of the peak strain, finally turned into a slow decrease process. The ductility of recycled coarse aggregate concrete became worse with the increase of freezing and thawing cycles. Theoretic stress-strain curve of recycled coarse aggregate concrete after different cycles of freezing and thawing was presented and it was in good agreement with the experimental results from the other researcher.