Experimental response of high-strength fiber-reinforced concrete slabs to blast loading

摘要

Fibre reinforced concrete has emerged as a suitable material for the design and building of structures aimed to resist highly dynamic events such as impacts, earthquakes and explosions. In the latter case, recent studies have shown the paramount role played by the mechanical properties related with fracture in the overall behaviour of concrete structural elements when subjected to blast loading. In this work an experimental campaign over high-strength fibre reinforced concrete slabs subjected to blast loading is presented. With the aim of analysing the influence of the softening behaviour in the structural response of the slabs subjected to blast loading, three self-compacting high-strength concretes reinforced with steel fibers have been designed. The three of them shared the same matrix bud had different levels of fiber reinforcement (low, intermediate and high). The mechanical characterization conducted later over the three concretes, including fracture energy measurements at high strain rates, has confirmed the remarkably different softening behaviours achieved with the three mixes designed. These concretes have been subjected to a campaign of blast tests consisting on submitting series of concrete slabs, one of each type of concrete, to the same explosive load. In order to have a control on the experimental scatter of the results, the test is repeated three times with the same explosive load so that results of at least three samples of each concrete are available at the end of the campaign. The preliminary results provided in this paper show a clear influence of the fibre content in the crack patterns registered in the different concrete mixes after the tests.