Experimental investigations on hot-driven structural rivets in historical French and Belgian wrought-iron structures (1880s-1890s)

When assessing the structural safety of historical metal structures, the understanding of the construction materials, their properties and modes of construction is a prior concern. Available information on historical riveted connections, however, is very limited. Analyzing the present state of these connections to better understand their actual structural behaviour is therefore essential. Through experimental work, we investigated the geometry and metallography of wrought-iron rivets dismantled from four bridges and buildings (1880s-1890s). The experimental results were then compared to historical literature. This paper reports the original design, manufacturing and installation of hot-driven rivets through four case studies and discusses the impact of these parameters on the behaviour of the connections. Results showed that the geometrical affinity of rivets together with their grain flow allow the original design and driving technique to be identified. The provided findings constitute supportive tools when assessing and renovating historical riveted structures.