Abstract:

Coral reef limestone serves as a critical foundation bearing layer and natural construction material for tropical island engineering. Its distinct biogenic origin imparts mechanical behaviors that differ fundamentally from those of terrigenous rocks. This paper systematically reviews recent advances in the microstructure characterization, mechanical behavior evolution, multi-field degradation, and numerical modeling of reef limestone. At the micro-scale, the hierarchical pore structure and its digital characterization methods are elucidated, and the guiding role of biogenic features on crack paths is clarified. Regarding mechanical properties, the damage mechanisms of reef limestone under static loading are discussed, revealing that lateral damage at the dilation point substantially exceeds axial damage, which is a key characteristic of its “crack initiation sensitivity”. Under dynamic impact, reef limestone exhibits significant strain-rate effects and energy absorption capacity. In multi-field coupling environments such as ocean acidification and thermal damage, a thermal damage threshold of 400°C is identified, and chemical dissolution is confirmed to reduce rock strength by 48.1% ~ 60.3% in the short term. At the theoretical model level, the applicability of the binary-medium constitutive model in capturing the “rock-soil” transitional failure process of reef limestone is evaluated, noting that the physics-based calibration of the breakage ratio remains a core challenge. At the frontier methodology level, the role of pore tensor theory in quantifying microstructural anisotropy is discussed, along with the potential of artificial intelligence approaches, such as generative adversarial networks and physics-informed neural networks, in addressing data scarcity and enabling cross-scale parameter prediction.

Key words: coral reef limestone, biogenesis, mechanical damage, constitutive model, artificial intelligence