Reinforced cement concrete (RCC) shelter and prediction of its blast loads capacity

Abstract

Reinforced concrete (RC) blast shelters are of momentous importance during warfare. On-the-ground shelters are also used to store chemical explosives, ammunition, and artillery. Functional requirements of blast shelters are entirely different from ordinary residential/commercial or institutional structures and therefore very rich specifications are used for their design and construction. Thus, blast shelters are quite sturdy and robust. Evaluation of the blast resistance of such structures is a topic of research interest, particularly under the circumstances like prevailing in Ukraine, Afghanistan, Iraq, and Syria. These RC structures are subjected to extreme impulsive loadings from blasts and explosions. In the present study, the RC on-the-ground blast-resistant shelter of a novel interior cylindrical configuration consisting of vertical and inclined walls with a flat roof in M40 concrete and Fe500 steel is proposed and its investigation is carried out under two different blast scenarios namely; spherical air detonation (SAD) and hemispherical surface detonation (HSD) using ABAQUS/Explicit code. A parametric study is performed by varying standoff distance, explosive weight, blast height, steel percentage, and concrete strength. The Concrete Damage Plasticity model is implored for nonlinear elastic and inelastic behaviors, degradation of stiffness, and loading rate effect on concrete. Re-bars of steel are idealized with the classical plasticity model following elastic–plastic constitutive law. For SAD and HSD, safe on-the-ground and free-air standoff distances, as well as safe blast pressure, are predicted. Results showed that the proposed RCC shelter can withstand blast loads of 4.98 MPa against SAD and 0.93 MPa against HSD.