Blast resistance of slurry infiltrated fibre concrete with hybrid fibre reinforcement

Abstract

This paper investigates experimentally the blast resistance of slurry infiltrated fibre concrete (SIFCON) with hybrid fibre reinforcement realized by various combinations of polypropylene (PP), aramid, carbon, glass, wollastonite and steel fibers. The binary reinforcement systems were designed using the combinations of steel/PP, steel/aramid, steel/glass, steel/wollastonite and steel/carbon fibres with various fibre geometry. Six different batches (including one reference specimen) were examined with aim to determine the influence of the parameters of hybrid reinforcement on blast resistance of the concrete. Mechanical parameters at quasistatic load (flexural strength, compressive strength) were determined and load-deflection curves were captured. Real blast tests were performed on the slab specimens (500 × 500 × 40 mm) according to the modified methodology M-T0-VTU0 10/09. The change of the ultrasonic wave transit time before and after the blast load in certain measurement points, damage of the slab, the weight of fragments and their damage potential were evaluated and compared. The results indicate, that hybrid fibre reinforcement, when properly designed, can highly enhance overall blast resistance of SIFCON and can significantly reduce the spalling. Steel-aramid combination brought the best blast resistance.