Blast Resistance of FRP-Strengthened Masonry Walls. I: Approximate Analysis and Field Explosion Tests

An approximate analysis method is proposed to determine the blast resistance of fiber-reinforced polymer (FRP)-strengthened masonry walls. The method relates the static to dynamic response by incorporating the strain rate effect on the material strength and a dynamic load factor for the applied peak load. Based on the method, 18 full-scale masonry walls reinforced with three different FRP systems were designed and subjected to field explosions, using charges of 27-ton TNT in one test and 5-ton TNT in the other. For each test, the walls were placed at three different standoff distances and orientations to the blast source. The response of the strengthened walls under blast was monitored by high-speed data acquisition systems. Post-test observations indicated no visible damage, crack, or debonding in any of the walls, thus confirming the effectiveness of the FRP retrofit technique in blast protection. The data presented are valuable for validation of analytical or numerical models.