Near-field Explosion Effects on Reinforced Concrete Columns

Abstract

Explosion effects on critical infrastructures have been an area of intense research over the last few decades; especially after the Oklahoma City bombing. The increase in research activities is attributable to the increasing number of terrorists’ attacks and incidence of accidental explosions around the world. The consequences of terrorists’ attacks using explosives and accidental explosions can be widespread and lead to damage to infrastructures and fatality to occupants of buildings. Thus building owners, government departments as well as professionals are seeking to better understand the response of structural systems, especially reinforced concrete columns, to blast loading. A significant amount of research work has been conducted to study the response of structural and nonstructural building elements to blast loading. Most of this research has concentrated on elements of the façade of buildings such as infill walls and window glass. The research investigating the behaviour of structural elements such as columns and beams are limited to their behaviour under far-range explosions. There is a lack of research data on the behaviour of reinforced concrete columns subjected to near-field explosions. The research reported in this paper was designed to investigate the effects of nearfield explosions on reinforced concrete columns with different transverse reinforcement detailing and at scaled distances less than 1.0 m/kg1/3. The results of the live explosion testing show that the effect of transverse reinforcement detailing is not significant at the high scaled distances. At smaller scaled distances, however, columns with close transverse reinforcement spacing performed better than companion columns with conventional transverse reinforcement spacing. Thus, reinforced concrete columns designed and detailed for areas of high seismicity have an inherently higher blast resistance in comparison with columns designed for areas of low seismicity or for gravity load resistance only