Experimental and numerical investigation of damage assessment in high-strength concrete slabs subjected to contact explosions

Explosive events can cause severe structural damage, driving the need for reliable strategies to enhance resistance against blast loading. High-strength concrete is a promising material widely used in protective structures. However, quantitative assessment of its blast resistance, through determination of the failure coefficient, remains limited. This study presents a comprehensive experimental–numerical investigation aimed at evaluating the failure coefficient of cast-in-place M60 high-strength concrete slabs subjected to contact explosions. A total of 40 controlled blast tests were conducted on two slab sizes, during which key damage parameters, including crater radius, penetration depth, and blasting funnel volume, were systematically measured. In parallel, three-dimensional numerical simulations were performed using the Riedel–Hiermaier–Thoma concrete model, coupled with Smooth Particle Hydrodynamics and Jones–Wilkins–Lee equation explosive modeling. The numerical results show good agreement with experimental observations, with a maximum deviation of 12.6% in crater radius. The obtained results are valuable for the preliminary prediction of failure coefficients by linear regression. A conservative failure coefficient of k = 0.1732 is proposed for M60 high-strength concrete, which is significantly lower than that reported for normal-strength concrete. In addition, the findings are significant in the design and estimation of blast protection performances of structures.