Failure criterion and elasto-plastic constitutive model of seawater concrete incorporating coral aggregate subjected to triaxial loading

Abstract

Recently, there has been a growing interest in utilizing coral reef debris as a replacement for river sands and natural coarse aggregates (NA). A novel type of seawater concrete, designated as CAC, was developed to effectively utilise raw coral debris and reduce material transportation costs. This study aimed to examine the mechanical properties of CAC under both uniaxial and triaxial loading conditions. Consequently, 18 prism uniaxial specimens and 90 triaxial cylinder specimens were prepared, considering concrete strength (C20, C40), replacement ratio of coral coarse aggregate (CA) (50 %, 75 % and 100 %), and lateral stress ratio (0, 0.1, 0.2, 0.3 and 0.5). The results indicated that the increase in peak stress and strain is associated with the triaxial stress ratio and the cylinder compressive strength of coarse aggregate. Furthermore, the compressive meridian of CAC is lower than that of conventional concrete. Based on the test results in this study, a modified William-Warnke failure criterion for CAC was established. Additionally, an elasto-plastic model considering a modified hardening and softening law was suggested for CAC under tri-axial loading. The proposed models were found to be well verified by the test results.