Dynamic response and damage assessment of AAC masonry walls reinforced by spraying polyurea under blast load

The autoclaved aerated concrete (AAC) blocks are becoming increasingly favored as infill material for masonry structures due to their advantageous characteristics, including a low mass ratio, excellent thermal insulation, and energy absorption. However, the susceptibility of AAC to fragmentation and low strength subject to blast loads pose risks to human safety. In response, polyurea, known for its exceptional protective properties, has emerged as a viable solution for enhancing the blast resistance of AAC masonry walls. The effectiveness of polyurea reinforcement under blast load was investigated through a series blast tests of full-scale wall specimens. The specimens consisted of one unreinforced wall, three single-sided polyurea reinforced walls, and one double-sided polyurea reinforced wall. The findings indicate that the unreinforced masonry wall experienced catastrophic damage,when subjected to near explosion of small equivalent TNT. Conversely, the specimen blast resistance and fragment dispersion were significantly improved by both single-sided and double-sided polyurea reinforcement. A finite element (FE) model is established and validated by the displacement data and damage obtained from tests. Furthermore, the protective effect of polyurea reinforced AAC masonry wall under different blast loads was investigated. The damage assessment was conducted and the corresponding damage level diagram was established,providing a practical reference for the design of polyurea reinforced AAC masonry walls with blast resistance.