Blast resistance performance of RU-NC-RU sandwich structures subject to internal explosion: Experiment and simulations

• Published in: Construction & building materials Vol. 493; p. 143288
• Main Authors: Peng, Yong, Zhang, Qirui, Jiang, Haojie, Lu, Qiu, Cheng, Hao, Zhang, Kefan, Li, Xiangyu
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 26.09.2025
• Subjects: Blast resistance; Dynamic response; Internal explosion; Parametric analysis; RU-NC-RU composite sandwich panel; Dynamic response; RU-NC-RU composite sandwich panel; Parametric analysis; Internal explosion; Blast resistance
• ISSN: 0950-0618
• DOI: 10.1016/j.conbuildmat.2025.143288

Reinforced ultra-high performance concrete (RU) - normal concrete (NC) -RU (RU-NC-RU) composite sandwich panel is a novel structure which potentially combines high blast resistance with high cost-effectiveness. To investigates the blast resistance performance of the composite panel, internal explosion experiments on RU-NC-RU sandwich panel were firstly conducted through a specially designed experimental apparatus, and the charge was 30g-60g. Dynamic responses of the composite panel and full-field strain distribution on the back surface under internal blast loading were captured through 3D-DIC technique. Numerical simulation model for dynamic response of the sandwich panel under internal explosion was then developed, and verified through three aspects: overpressure of the internal blast wave, the failure mode and the mid-span deflection evolution of the composite panel. Key parameters were systematically analyzed to evaluate their effects on dynamic response and failure mechanisms. Experimental results revealed that increasing TNT mass exacerbated structural damage, leading to a shift in crack patterns and caused irreversible plastic deformation to dominate the overall failure of the structure. Attributed to dispersed stress gradients, increasing panel thickness from 40 to 55 mm suppressed crack propagation and reduced residual deflection by 57 %. When the NC core layer proportion γ is less than 60 %, blast resistance enhances sharply with the decrease of γ, while for γ= 0–60 %, the maximum mid-span deflection varied minimally and an approximate plateau can be observed. Also, analysis of cross-sectional reinforcement ratio effects revealed a two-stage hardening effect, indicating a practical threshold for design. The findings provide actionable insights for optimizing composite sandwich structures in protective engineering. •Dynamic response of RU-NC-RU sandwich panel subjected to internal explosion was tested for the first time.•Displacement and strain fields for the composite panel were obtained through 3D-DIC.•Damage mechanisms and crack propagation patterns under different TNT mass were revealed.•Effects of core layer proportion, panel thickness, and cross-sectional reinforcement ratio on blast resistance were analyzed.