Drop weight impact on hybrid-fiber ECC blast/shelter panels

This paper presents the results of an experimental study to evaluate the damage and failure mode of hybrid-fiber engineered cementitious composite (ECC) panels caused by large projectiles or fragments with the aim towards quantifying the extent to which hybrid-fiber ECC improves the resistance of blast panels against impact loading. Drop weight tests are conducted on full-scale blast/shelter panels (2 m x 1 m x 0.1 m) made of hybrid-fiber ECC to study their response and performance under impact loading. Conventional steel reinforced concrete (RC) blast panels are also tested to identify the advantages of using ECC in this application. Both the drop weight projectile with a hemispherical head and the panel specimen are instrumented to facilitate evaluation of the global and local response. The damage incurred on the blast panels are examined in terms of indentation depth, crater size, and cracking condition. Results show that under the drop weight hammer impact, the hybrid-fiber ECC panels exhibit improved resistance and reduced damage compared to the RC panels in terms of the following: (1) much smaller indentation depth and crater size on the impact face, (2) much smaller exit crater on the distal face after perforation, (3) larger volume of material involved in energy absorption providing better resistance, and (4) significant improved impact resistance and energy absorbing capacity against multiple impacts.