Experimental investigation of mechanical properties of coral concrete under cyclic compression

Abstract

The increasing depletion of terrestrial resources and the growing demand for offshore infrastructure have heightened the need for sustainable construction solutions utilizing locally available marine materials. Coral concrete, composed of coral coarse aggregates, coral sand, and seawater, emerges as a promising alternative to conventional concrete, particularly for construction on remote islands and reefs. This study presents a pioneering experimental examination of the cyclic compression behavior of coral concrete, thereby addressing a research gap in existing literature. It investigates the mechanical behavior of coral concrete under cyclic compression loading, with a focus on its compressive strength, stress-strain response, stiffness degradation. The results indicate that coral concrete exhibits markedly different mechanical responses when subjected to cyclic loading, showing up to a 20% reduction in average compressive strength and a maximum degradation of 23.1% in secant elastic modulus compared to specimens not exposed to cyclic loading. The initiation and propagation of microcracks occurred rapidly, primarily along the aggregate-paste interfaces due to the porous and fragile nature of coral aggregates. These findings not only underline the vulnerability of coral concrete to fatigue-related damage but also provide practical insights for the design and optimization of offshore and island infrastructures.