Investigation of bending performance in recycled aggregate pervious concrete under static and fatigue load

Recycled aggregate pervious concrete (RAPC) has gain widespread attention for its environmental sustainability and functional performance in urban infrastructure. While prior research has extensively studied its compressive strength and permeability, limited research addresses its bending performance under static and fatigue loads, which is essential for low-traffic road applications. This study addresses this gap by systematically analyzing RAPC's bending performance and crack propagation mechanisms, incorporating the unique effects of its porous structure and recycled aggregate (RA) characteristics. RAPC mixtures with porosity levels of 24.2%, 18.3% and 14.3% were evaluated to identify the influence of porosity on mechanical behavior. Mesoscopic fracture analysis revealed cracks primarily initiating in old mortar and clay brick near large pores, followed by the interfacial transition zone (ITZ). Experimental results showed bending strength values at 24.8%, 19.3%, and 14.6% of compressive strength as porosity decreased. Fatigue life, analyzed using a Weibull distribution, was accurately predicted via a stress-porosity model (R² = 0.97), highlighting that fatigue life diminishes with increasing stress level and porosity. Notably, bending modulus evolution depends more on initial stiffness than stress level. Additionally, stiffness degradation and strain evolution followed a three-stage pattern: rapid initial deterioration due to weak aggregates, a stable intermediate phase, and accelerated loss in the final phase. These findings underscore RAPC’s viability for sustainable road infrastructure, with practical guidance on optimizing design and durability. The proposed fatigue life prediction model offers a valuable tool for service life evaluation, advancing RAPC's application in eco-friendly construction aligned with urban sustainability goals. • Static failure mode was revealed at the mesoscopic level preliminarily. • Influence of stress level and porosity on fatigue life were investigated. • Fatigue life prediction model was established. • Degradation process of mechanical indicators with fatigue cycles were revealed.