Damage behavior and assessment of polyurea sprayed reinforced clay brick masonry walls subjected to close-in blast loads

As a means to lessen the threat of an accidental blast, the polyurea sprayed reinforcement of masonry walls has attracted extensive attention. In this research, the detailed micro numerical models which can predict the nonlinear dynamic response of unreinforced clay brick masonry walls (URWs) and polyurea reinforced clay brick masonry walls (PRWs) under close-in blast were developed. The numerical simulation results were in good agreement with the field test results. Through numerical simulation and structural resistance model, the blast resistance mechanism of polyurea was revealed, and the damage behavior of polyurea rear spraying reinforced walls (PRRWs) and polyurea double-sided spraying reinforced walls (PDRWs) under different blast scaled dis-tance was clarified. By defining the damage parameters, i.e., internal crack rate and mass loss rate, the comprehensive effects of polyurea spraying position and blast scaled distance on the damage degree of wall were summarized. Finally, the retrieval map of damage modes for PRWs under close-in blast was established, which could provide specific guidance for the anti-blast protection design of PRWs.