Development of a novel energy fuse for enhancing blast resistance in masonry infill walls

This study investigates the effectiveness of autoclaved aerated concrete (AAC) blocks as vertically embedded energy fuses for enhancing the blast resistance of masonry infill walls. A novel configuration is proposed, in which AAC layers act as sacrificial and replaceable elements that absorb and redistribute blast energy before it is transmitted through the wall. Validated finite element models were developed to simulate the structural behaviour of infill walls subjected to a wide range of explosive charge weights and standoff distances. Key response parameters, including support reactions, energy dissipation, displacement, velocity, and stress distribution in mortar, brick, and AAC components, were systematically evaluated. The results demonstrate that the AAC fuse system significantly improves blast performance: peak wall displacement was reduced by up to 80 %, base reaction forces by approximately 7 %, and peak stresses in mortar and brick by 59 % and over 30 %, respectively. Additionally, the presence of AAC layers reduced sensitivity to boundary conditions, highlighting its potential in retrofit applications where full anchorage is not feasible. The system also enhanced structural damping, promoted more uniform deformation patterns, and improved energy absorption over time relative to conventional masonry walls. These findings confirm that the proposed AAC energy fuse represents a practical and cost-effective strategy for improving the blast resilience of masonry infill walls, particularly in aging or vulnerable structures where traditional reinforcement methods may be difficult to implement. • A novel AAC fuse system is proposed to enhance blast resistance of infill walls. • FE models simulate response under various TNT loads and standoff distances. • The AAC fuse reduces displacement, base force, and stresses in walls significantly. • Performance is less sensitive to boundary conditions and anchorage limits. • AAC boosts energy absorption and enables low-cost, sustainable retrofitting.