A review on close-in blast performance of RC bridge columns

In recent decades, the increase in terrorist attacks highlights the necessity and importance of understanding of structural performance under accidental and intentionally malicious blast loads. As an important part of transportation infrastructure, bridges would inevitably suffer explosion hazards especially close-in explosion. Reinforced concrete (RC) bridge column is the most critical components of bridge structures, which is more prone to severe local damage under the action of close-in blast loading and can lead to progressive collapse with catastrophic consequences in most cases. Therefore, the blast performance of RC bridge columns under close-in explosions is of particular concern. Towards a better RC bridge column protection against close-in blast loadings, efforts have been mainly devoted to understanding dynamic response predictions of RC columns, numerical simulation techniques of close-in explosion and damage assessment of blast-damaged RC columns. This article presents a state-of-the-art review of the research status of RC columns subjected to close-in blast loads. The blast loading, experimental study and failure mode, uncoupled and coupled simulation method, damage assessment based on residual axial capacity, vulnerability analysis and machine learning are considered and reviewed. The merits and defects of the existing approaches are discussed, and some suggestions for possible improvement are proposed. Further investigation into the future development of this topic has also been identified.