Experimental and numerical study of G-HPC slabs rapidly repaired by G-HPC canvas and G-UHPC under contact detonations

Abstract

The rapid repair of engineering structures damaged due to explosions can enhance the structural impact resistance after an explosion, thereby reducing the potential for casualties and property losses. A novel concrete canvas was firstly proposed based on G-HPC (geopolymer-based high performance concrete), UHMWPEWF（ultra-high molecular weight polyethylene woven fabric), and 3D BFG (basalt fiber grid) to rapidly repair engineering structures and render their blast resistance. A sequence of contact blast tests was systematically conducted to verify the feasibility of the proposed G-HPC canvas. A normal reinforced concrete slab and a steel-wire mesh (SWM) reinforced G-HPC slab were initially damaged by the contact blast loading, afterwards, the damaged concrete slabs were rapidly repaired by G-UHPC (geopolymer-based ultra-high-performance concrete) and the novel G-HPC canvas. The rapidly repaired concrete slabs were subsequently tested by contact blast loading. A precise 3D finite element model was then developed and calibrated based on the experimental results. Eventually, numerical simulations were performed to better understand the contribution of main parameters including repair materials filling the internal slab, steel-wire mesh, G-HPC canvas location and its thickness towards the improvement of the rapidly repaired slabs against the contact blast loading. The experimental and numerical results indicated that the SWM reinforced G-HPC slab has superior blast-resistance compared with the RC slab and the proposed method to rapidly repair the damaged slabs was feasible. The G-HPC canvas should be placed properly since the location of the G-HPC canvas is related to whether fragments are produced on the rear surface of the damaged slab. Increasing the G-HPC canvas thickness and the layers of SWM could significantly reduce the damage area of the repaired slab.