Performance of brick-filled reinforced concrete composite wall strengthened with C-FRP laminate(s) under blast loading

From the safety of the structure and security point of view, the role of free-standing compound wall is still relevant. Such unreinforced walls have limited flexural capacity under the effects of blast shock -waves and may suffer from severe damage with catastrophic out-of-plane failure consequences. The pre-vious novel study was conducted by the authors on free-standing reinforced concrete (RC) wall, 6000 mm x 2500 mm x 230 mm (length x height x thickness), having (i) 70 mm wide cavity, the cavity filled with (ii) bricks on edges, and (iii) sand as softcore materials, subjected to explosive charge weights of 3.50 and 7.20 kg-TNT at standoff distance 3.50 m and height of burst 1.25 m using the dynamic com-puter code, ABAQUS/Explicit-v.6.15. The cavity wall filled with softcore material as bricks was found to give an outstanding performance while that without softcore displayed an inferior response than the wall with sand as softcore. In the present work, the authors have further extended the research by investigat-ing the performance of the free-standing brick-filled RC composite wall under the explosive weights of 1, 5, 10, 15, and 20 kg-TNT at a very close standoff distance (0.50 m). A well-known Concrete Damage Plasticity Model (CDPM) considering strain rate effects is used to define the constitutive relation of con-crete and infilled bricks. The nonlinear behavior of the reinforcing bars is also taken into account. Coupled-Eulerian-Lagrangian (CEL), an advanced computational modeling technique, is adopted to sim-ulate the explosion effect on the wall. Radial cracks mainly at the blast height level develop under explo-sion loads < 5 kg-TNT. For higher explosive loads, the bulging of the concrete walls occurs. To make the wall sustain the damage due to the blast, it is strengthened with a single layer of the carbon-fiber -reinforced-polymer (C-FRP) laminate of minimum thickness 0.15 mm. The load-carrying mechanisms are explained. Effect on strength parameters of the wall contributing to its improved blast performance is discussed. Multi-layers of the C-FRP are also considered against higher explosive loads for satisfactory blast performance of the wall.Copyright (c) 2022 Elsevier Ltd. All rights reserved.Selection and peer-review under responsibility of scientific committee of the International Conference on Advanced Materials and Mechanical Characterization (ICAMMC 2021).