High Performance Concrete Beams Subjected to Shock Waves from Air Blast

摘要

This investigation involves testing of reinforced concrete beams of both normalstrength concrete (NSC) and high strength concrete (HSC). A total of 33 beams were tested, of which 26 were subjected to shock wave loading from air blast. The different concrete grades used were compressive cube strengths 40, 100, 150 and 200 Mpa, respectively. Some beams of the highest concrete grade contained steel fibers. Also, beams with two concrete layers were tested, i.e. the bottom layer of concrete grade 40 and the top layer of grade 200. The amount of reinforcement was varied in order to study the mechanical properties of the beams. Both the load capacity as well as the deflection capacity were studied. In the static tests, the beams were loaded with four point loads. The shock wave tests were performed in a shock tube. The mass of the explosive charge was varied for the different beams and ranged from 1.0 kg up to 7.0 kg. All beams subjected to static loading failed in flexure. In the dynamic tests, the failure mode changed for some beams in relation to the static tests. Beams of concrete grades 40, 100, 150 and 200 without fibers and with a high ratio of reinforcement exhibited shear failure. Beams of concrete grades 100 (with a low ratio of reinforcement), 200 containing steel fibers and beams with two concrete layers failed in flexure.