Fracture analysis of seawater sea-sand recycled aggregate concrete beams: Experimental study and analytical model

Seawater sea-sand recycled aggregate concrete (SSRAC) has garnered significant attention from engineers involved in various coastal engineering projects. Fracture constitutes one of the primary failure modes of SSRAC, and the accurate analysis of its fracture behavior is crucial for application. In this present study, SSRAC with 50% aggregate replacement was subjected to three-point bending tests to evaluate its fracture performance. Specific methodologies for calculating SSRAC fracture toughness were introduced, taking into account the effects of material microstructures and specimen boundaries. By comparing the fracture properties of SSRAC specimens with varying initial notch lengths, the size effect was addressed by using established methods, resulting in a constant fracture toughness value. Furthermore, the methods for analyzing the fracture of un-notched specimens were developed, considering fracture path analysis and the influence of internal defects. Notably, this research demonstrated that small specimens and established methodologies efficiently predict the fracture behavior of larger specimens, providing practical insights for engineering applications.