یک ارزیابی تجربی از مقاومت انفجاری پل های ورقه ای کامپوزیتی بر پایه بتن ناهمگن
Abstract
1- Introduction
2- Experimental program
3- Conclusions
References
Abstract
Because of the current geopolitical situation, research on improving the resistance of the civil and transport infrastructure to blast or impact loads has gained considerable attention. This paper presents the results of full-scale blast experiments designed to characterize the resistance of concrete-based composite bridge decks subjected to close-in blast loading. Three composite decks with different degrees of heterogeneity were proposed and tested: a slab with basalt fiber meshes in multiple layers along the depth of the specimen, a slab with recycled textile sheets 100 mm in total thickness, and a typical hollow-core prestressed slab. The dependence of the extent of the blast damage on the material characteristics of the composite material was studied. A detailed study of the damage to the specimen caused by the close-in explosion found apparent delamination of all tested composite specimens. The heterogeneity of the layered composite material converts the blast damage due to internal rebounds into layer delamination.
Introduction
Due to the current geopolitical situation, there has been a considerable increase in the number of terrorist acts in recent years. The need to improve the resistance to blast or to impact of the civil and transport infrastructure has led to increased interest in research and development on various materials, and on their resistance to high strain-rate loading. This paper presents the results of a full-scale experimental program focused on the blast resistance of hybrid concrete specimens subjected to close-in blast loading, and the dependence of the resistance on the composition and the material properties of the specimen. This research program built on previous research conducted by the authors. Since 2010, the authors have been conducting experiments with an unchanged arrangement, using various types and compositions of concrete, ranging from normal-strength concrete without distributed reinforcement (NSC) to ultrahigh-performance fiber-reinforced concrete (UHPFRC). The results of earlier experiments are presented in [1–3]. To explore ways of further enhancing the blast resistance of concrete, the experiments presented in this paper introduced three specimens with an atypical internal structure made of newly-developed concrete-based composite materials utilizing basalt fiber meshes and recycled textile sheets. One conventional specimen with a hollow core was also used for comparison. 1.1. State-of-the-art on blast performance of composites Shock wave propagation through a heterogeneous environment is a very complex issue, because the shock wave is partially reflected from and partially passes through any interface of environments with different densities. This partial reflection can effectively mitigate the effects of a blast wave. This paper builds on the research on air shock wave propagation and interactions in heterogeneous environments previously conducted by the authors, see [4,5]. The use of heterogeneous materials in blastresistant devices and structures can significantly increase their effectiveness. Composite building materials are generally well suited to achieve the required material heterogeneity.