Numerical investigation on CFRP strengthening and reinforcement bar detailing of RC columns to resist blast load

The failure of column, which is a critical compressive structural member of a building, may lead to devastating progressive collapses. The present numerical study involves investigation on the performance of as-built and strengthened RC columns using 0°/90° CFRP layers under blast loading. A nonlinear FEA program, LS-DYNA was employed to study the RC columns response when subjected to blast loading. Blast field test data from recent literatures was employed for validation and further parametric studies. Variables considered were different charge masses, height of bursts, concrete compressive strengths, standoff distances, tie spacings, transverse reinforcement steel detail schemes, and 0°/90° CFRP layers. It was revealed that scaled distance parameters had a significant effect on the behaviour of RC columns under blast loading. Compared to as-built column, 0°/90° CFRP strengthened RC columns displayed excellent blast resistance. Transverse reinforcement steel details had a significant effect on lateral displacement response and failure modes of RC columns. Compared to conventionally-detailed columns, seismically-detailed columns and transverse reinforcement steel bars accompanied with square-diamond shaped ties exhibited enormous blast resistance capacity.