Quentin Collette

Evolution of historical riveted connections: joining typologies, installation techniques and calculation methods

Riveting was one of the major joining techniques used for the assembly of iron and steel structures. Being widely used since 1860, today most of the existing riveted structures need maintenance and possibly strengthening. This research aims to improve the existing knowledge on this type of fasteners in order to stimulate less intrusive interventions during renovation, respecting the historical character of these structures. To reach this goal, a multidisciplinary literature study is carried out, dealing with three related topics: historical analysis (historical context, fields of use, types of riveted connections, comparison with other contemporary joining techniques), technical subjects (definition, material, joining typologies, forms of the rivet head, installation processes and techniques) and structural understanding (bearing principle, strength of riveted connections, calculation methods).

Technical improvements in 19th-century Belgian window glass production

Glass was used since the Roman age in the building envelope, but it became widely applied together with iron since the 19th century. Belgium was a major producer of window glass during the nineteenth century and the majority of the produced window glass was exported all over the world. Investigating the literature on the development of 19th century Belgian window glass production is therefore internationally relevant. In the 17th century, wood was replaced as a fuel by coal. In the 19th century, the regenerative tank furnace applied gas as a fuel in a continuous glass production process. The advantages were a clean production, a more constant and higher temperature in the furnace and a fuel saving. The French chemist Nicolas Leblanc (1787-1793) and later the Belgian chemist Ernest Solvay (1863) invented processes to produce alkali out of common salt. The artificial soda ash improved the quality and aesthetics of the glass plates. During the 19th century, the glass production was industrialized, influencing the operation of furnaces, the improvement of raw materials as well as the applied energy sources. Although the production process was industrialized, glassblowing was still the work of an individual. By improving his work tools, he was able to create larger glass plates. The developments in the annealing process followed this evolution. The industry had to wait until the invention of the drawn glass in the beginning of the 20th century to fully industrialise the window glass manufacture process.

Victor Horta’s Iron Architecture: A Structural Analysis

The internationally acknowledged Art Nouveau architect Victor Horta built remarkable artifacts of public iron architecture in Brussels. His projects display an innovative philosophy based on apparent iron frameworks used in a very efficient manner. As a supplement to the ample historical and architectural studies on Belgium’s most famous Art Nouveau architect, this paper puts Horta’s innovative structural practice of iron into the picture. To reach this goal, a structural analysis of four of Horta’s most interesting projects is carried out, going into the following topics: conceptual philosophy (structural typology), building techniques (shapes, connection details) and the coherence of the structural logic (structural usefulness).

Towards A Non-destructive Methodology ToDistinguish Wrought Iron From Mild SteelIn 19th Century Structures

During the 19 th century various new construction materials became available in a short time. This paper deals with the quest for a methodology to differentiate wrought iron from mild steel by using a combination of several onsite nondestructive testing instruments. A mobile Vickers hardness tester and an optical microscope were used to determine the hardness and analyze the microstructure after onsite polishing and nital etching of historic wrought iron and mild steel structures. The historic specimens were also tested in a destructive way (tensile test) to obtain values for the mechanical properties and relate these values to the NDT results. Although the hardness measurements showed very large scatter, a trend in the measurements could be defined: large variations in local hardness measurements are a clear indication of wrought iron, which can be explained by the inhomogeneous micro-structure. Low variation in hardness is typical for mild steel. In the latter case a conversion from hardness to tensile strength is possible. The obtained dataset, coming from different Belgian structures dating from 1895 to 1905, is compared to datasets originating from the UK and US in order to position the Belgian historical iron alloys within a larger international context.