Study on Flexural Performance of Recycled Aggregate Concrete Beams Incorporating Glazed Hollow Beads

Recycled aggregate concrete incorporating glazed hollow beads (GHBRC) achieves the dual objectives of energy conservation and emission reduction by combining recycled coarse aggregate with glazed hollow bead aggregate, aligning with the construction industry's "dual-carbon" goals for the development of low-carbon concrete. This study systematically investigates the flexural performance of GHBRC beams to establish calculation formulas for ultimate limit state bearing capacity and serviceability limit state verification. Six full-scale GHBRC beams were tested under simply supported conditions with two-point symmetric mid-span loading. Three critical variables (concrete composition, longitudinal tensile reinforcement ratio, and stirrup reinforcement configuration) were examined. Experimental results indicate that GHBRC beams exhibit failure modes consistent with conventional concrete beams, confirming the validity of the plane section assumption. At identical reinforcement ratios, GHBRC beams demonstrated a 3.1% increase in ultimate bearing capacity and an 18.78% higher mid-span deflection compared to ordinary concrete beams, highlighting their superior deformation performance. Building on methodologies for conventional concrete beams, this study recalibrated key short-term stiffness parameters using a stiffness analytical method and proposed a computational model for mid-span deflection prediction. These findings provide theoretical and practical foundations for optimizing the structural design of GHBRC beams in alignment with sustainable construction objectives.