Numerical Study on the Uplift Response of RC Slabs Subjected to Blasts

Abstract

This study investigated the response of reinforced concrete (RC) slabs in building structures to internal explosions. The performances of two slabs designed in accordance with the protective structural design and conventional gravity design approaches were evaluated in terms of midspan displacements, support rotations, and damage patterns. Data from available slab blast experiments in the open literature were used to validate the methodology. A numerical study was carried out for various high-explosive charges detonated underneath the RC slabs. Detonations were simulated using airblast-loading functions. The flexible boundary conditions for the slabs were provided by a one-story single-bay RC frame consisting of beams and columns. All of the reinforcements of the slabs, beams, and columns were modeled explicitly using line elements inserted into the volumetric finite-element mesh of the concrete material. Envelope values of the rebar rupture strain were also used in the parametric study. Results from the numerical study showed that rebar rupture strain was a key factor in the blast performances of both slabs. Current protective design approaches to RC slabs mainly consider support rotations. It is recommended that rebar rupture strain also be accounted for in protective design.