Experimental and numerical studies on the structural response of normal strength concrete slabs subjected to blast loading

Abstract

To assess the blast performance of concrete structures, a shock tube has been used to simulate blast loading against concrete slabs of two different mixes ordered as C45/55 and C20/25. The C45/55 slabs were tested without reinforcement, whereas the C20/25 slabs were tested both with and without reinforcement to investigate the effect of adding steel bars on the structural response. The performance of the shock tube itself was also evaluated. Compression tests on cubes and cylinders of both concrete recipes were performed to obtain material input data for numerical simulations. Numerous compression tests were also conducted using the C20/25 mix to obtain insights into the statistical variation in the material properties as concrete is inherently heterogeneous at the macroscopic level. In addition, tensile splitting tests were conducted on both materials. The shock tube tests show that the boundary conditions are important and that the reinforcement will direct the crack pattern. Fluid-structure interaction (FSI) effects are not dominant for this particular problem, because the concrete slabs suffer relatively small deformations before through-thickness cracks appear. Once cracks extend through the thickness, FSI effects may become influential, but it appears that when this occurs there is little or no residual capacity left in the slabs. Numerical simulations were used to investigate the influence of various parameters, revealing that the results are highly dependent on the boundary conditions and particularly on the tensile strength of the concrete. It was found necessary to model the entire clamping assembly to recreate the experimental observations.

A review on the performance of reinforced concrete structures under blast loading

“…Mao et al [20] observed that with the increase of fiber volume in Ultra high-performance fiber-reinforced concrete slab, the deflection in the slab is decreasing therefore, it indicates the increased blast resistance of UHPFRC slab. Kristoffersen et al [21] found that the strains and the damage in the concrete slabs were reduced in the analysis when steel-bar reinforcement was included against the blast loading. Based on the results available in the literature, the response of slab in terms of spall radius corresponding to various charge weights is shown in Fig.…”

Blast Loading of Concrete Pipes Using C-4 Charges

“…The pipe was meshed by 8-node linear brick elements with reduced integration. An element size of about 10 mm was used (about 55000 elements in total), offering a fair compromise between speed and accuracy [6]. The "concrete damage plasticity model" in ABAQUS [8], based on the work by Lubliner et al [11] and Lee and Fenves [12], was used to represent the concrete material.…”

“…The "concrete damage plasticity model" in ABAQUS [8], based on the work by Lubliner et al [11] and Lee and Fenves [12], was used to represent the concrete material. The calibration was based on previsously obtained material data [6,13], and scaled according to the data provided by the manufacturer. The material has separate damage parameters for compressive and tensile damage.…”

“…Several studies have investigated blast loading against general plane concrete structures, such as beams [5] or slabs [6,7]. Few studies have considered blast loading against tubular concrete structures, hence a partial goal of this study is to expand the available experimental database on this topic.…”

Increasing Impact Endurance of Fiber Concrete

“…Another direction is the modification technology of concrete structure through the introduction of low hard porous disperse components (damping additives) into the concrete mix. This approach to the increase of concrete impact endurance was studied by R. Oyguc [1], M. Kristoffersen [2], A. Maazoun [3], Z.I. Syed [4], K. Makita [5], etc.…”