High-Strength Materials for the Response Enhancement of Reinforced Concrete Structures Subjected to Cased Explosive Charges

Abstract

The paper studies the flexural responses of one-way reinforced concrete structural elements subjected to cased explosive charges to explore the suitability of using high-strength materials for such scenarios. The detonation of cased explosive charges leads to the generation of fragments due to the rupturing of the casing housing the high explosive charge. Consequently, structures subjected to the detonations of cased explosive charges are acted upon by both the blast wave (due to the detonation of the high explosive charge) and the fragments. This study was motivated by the fact that although similar studies have been conducted to explore the suitability of using high-strength materials for scenarios involving bare (uncased) explosive charges, such studies are still uncommon when it comes to cased explosive charges. The methodology adopted herein consisted of developing a semianalytical approach that was validated against (1) the results of experimental static tests available in the literature, (2) the results of experimental blast trials conducted with bare (uncased) explosive charges that are available in the literature, and (3) the results of finite-element simulations, conducted by the authors due to the nonavailability of a relevant experimental data set in the public domain pertaining to cased explosive charges (to the best of the authors’ knowledge). Following the validations, the adopted semianalytical approach was further used for conducting detailed parametric investigations. It was observed that compared with the lightly cased explosive charge (casing to charge mass ratio=0.5), the peak structural displacements for the heavily cased explosive charge (casing to charge mass ratio=1.5) showed an increase of 50% (for high-strength materials) to 64% (for normal-strength materials). Moreover, compared with normal-strength materials, the application of high-strength materials was also noted to reduce the peak structural displacements by 9% to 23%, which indicated the increased measure of safety provided by the high-strength materials. In addition to this, compared with normal-strength concrete, the employment of high-strength concrete grades was also effective in limiting the fragment inflicted damage by 25% to 36%. Additionally, increasing the reinforcement ratio to 0.65% from 0.16% effectively reduced the peak structural displacements by 57% to 63%.