Enhancing energy dissipation in mortar utilizing recycled brick fine aggregate impregnated with polymer emulsion under uniaxial cyclic load

Optimizing the damping properties of materials can enhance the energy dissipation capacity of structures and mitigate the negative effects of dynamic loads on building components. This study investigated the effects of the polymer emulsion-impregnated recycled brick fine aggregate (PRBFA) replacement rate, emulsion-impregnation treatment method, and emulsion solid content on the dynamic damping properties of PRBFA-prepared mortar (PBM). Combined with microscopic tests, the enhanced damping mechanism of PBM was discussed. The results show that under the same stress amplitude, the equivalent damping ratio and loss modulus of PBM increase with the PRBFA replacement rate and emulsion solid content. The drying treatment of PRBFA demonstrates superior damping characteristics of PBM, with the equivalent damping ratio and loss modulus increased by 84.9%–129.4 % and 71.0%–117.2 %, respectively, compared to those of PBM with undried PRBFA. The damping enhancement of PBM is attributed to the weak interface between the aggregate and cement matrix, which facilitates slippage and friction. The damping layer formed between the high viscoelastic emulsion and the aggregate, or between the emulsion and the cement matrix, is conducive to energy dissipation. The optimal PRBFA replacement rate for balancing the mechanical and damping properties of PBM is between 38% and 60 %.