Complete Stress-strain Curves of Seawater Sea Sand Recycled Aggregate Concrete Under Uniaxial Compression

Abstract:

To explore the mechanical properties of seawater sea sand recycled aggregate concrete （SSRAC）， SSRAC prisms were designed with different mix proportions. The complete stress-strain curves were tested under uniaxial compression with the strain rates of 10^-5 s^-1 and 10^-2 s^-1. Failure modes of specimens and the peak stress， strain at peak stress and elastic modulus were analyzed. And the effects of the strain rate， replacement ratio of recycled coarse aggregate （RCA） and shell particle contents on the above indices as well as the dynamic increase factor （DIF） were discussed. Meanwhile， the pore distribution of SSRAC from computed tomography （CT） tests was used to explain the development of characteristic indices of stress-strain curves. Finally， based on the existing uniaxial compression constitutive models of RAC， the predicted complete stress-strain curve was obtained by taking the DIF of characteristic indices and the modified shape factor of descending branch into account.

Key words:recycled aggregate concrete (RAC);seawater and sea sand;strain rate;porosity;complete stress-strain curves