Experimental and numerical investigation of G-UHPC based novel multi-layer protective slabs under contact explosions

Abstract

Geopolymer based ultra-high performance concrete (G-UHPC) has been recognized as a ‘eco-friendly’ form of ultra-high performance concrete owing to its beneficial characteristics, e.g. waste utilization, reduction in carbon dioxide emission, low energy consumption, superior mechanical behavior and adjustable hardening time. Thus, G-UHPC is well suitable for the rapid construction of blast-resistant structures. In this study, four slabs, including a reference normal strength concrete (NSC) slab and three novel multi-layered composite slabs fabricated by G-UHPC, steel wire mesh (SWM) and energy absorber foam materials, were tested on their blast resistance against contact explosions and the corresponding numerical simulations were carried out. Four failure patterns (crater, crater and spalling, breach-perforation and breach-punching) were quantitatively characterized. The G-UHPC slab reinforced with SWM exhibited superior blast resistance as compared to the referenced NSC specimen. The low stiffness and shear strength of the energy absorber foam materials were the main reasons for the breach-punching failure mode. The acoustic impedance and compressibility of the energy absorber foam materials must be reasonably considered to achieve a positive effect on the blast resistance of the concrete slabs. The developed finite element mode could effectively predict the failure characteristics of the specimens.