Dynamic response of shock-tube tested reinforced concrete wall panels

Civilian structures and fortifications are primarily composed of reinforced concrete elements. The development of methods suitable for blast-loaded structural concrete elements requires experimental data for validation and an understanding of the structural response. Previous studies have focused either on variations in geometry and material properties or on realistic boundary conditions. This study complements existing experimental datasets on reinforced-concrete wall panels. In total, 29 shock-tube and 9 quasi-static tests were performed on geometrically half-scale wall panels with different load intensities, geometries, reinforcement configurations, and boundary conditions. The results showed that static and dynamic failure modes were similar: panels with stirrups failed in flexure, while panels without stirrups failed in flexural-shear. Significant arching action developed for both loading types, with flexural damage resulting in the wall retaining a large portion of its initial axial load after the test. Comparison of static and dynamic resistances showed that for panels without stirrups, dynamic resistance exceeded static resistance, whereas failure initiated at the same midspan displacement. This suggests that the deformation level should be considered when assessing the risk of flexural-shear failure. For panels with stirrups, dynamic resistance was initially governed by the direct compression strut capacity but converged with static flexural resistance at larger deformations. Predictive models for axial load, displacement, and reaction forces were evaluated and further developed. A simple spring model, based on rigid-body kinematics and static axial stiffness, was developed to predict axial loading due to arching action and showed good agreement with the tests. Simplified single-degree-of-freedom models and a multi-mode elastic model predicted displacement and reaction forces with good agreement. The experimental results were used to develop a novel closed-form model for predicting reaction forces. Conventional methods and the proposed closed-form model were used to derive iso-damage curves, which were then compared with experimental data. The results showed that the iso-damage curves provide satisfactory early approximations of the blast response. • 29 shock-tube and 9 quasi-static tests on half-scale RC wall panels, that cover slenderness, axial load, stirrups and boundary conditions. • Static–dynamic comparisons show flexural-shear triggered after deformation and time; force level alone does not govern failure. • Spring, SDOF and multi-mode models, with a new closed-form P–I method, predict displacements, arching action and support reactions.