Mechanical performance and failure criterion of coral concrete under combined compression-shear stresses

The mechanical performance of coral concrete under combined compression-shear stresses was investigated using the multifunctional true triaxial testing machine. The shear load-displacement curves, normal displacement-shear displacement curves, and shear failure modes were obtained. Based on the test results, the shear failure modes, deformation proprieties, peak shear strength, and shear strength components were analyzed. The results show that almost all coral aggregates on the shear failure surface are broken. With the normal stress ratio increasing, the fiction traces and tiny concrete debris on the shear failure surface increase, and the peak shear strength and corresponding shear displacement also increase. The shear strength components include cohesion strength, contact friction strength, and shear dilation strength, where the contact friction strength dominates the shear strength with the existence of normal stress. Based on different stress expressions, five failure criterion models are proposed, where the one based on stress invariant achieves the highest prediction accuracy. (c) 2021 Elsevier Ltd. All rights reserved.

Automated summary

The mechanical performance of coral concrete under combined compression-shear stresses was investigated, and the shear failure modes, deformation proprieties, and shear strength components were analyzed. It was found that with the normal stress ratio increasing, the peak shear strength and corresponding shear displacement also increase. Five failure criterion models were proposed, with the one based on stress invariant achieving the highest prediction accuracy.