100-year-old Hennebique concrete, from composition to performance

• Identification of the original composition of 100-year old hardened concrete samples.
• Analysis of the influence of concrete composition on durability, especially carbonation.
• Mechanical and durability performance is remarkably good after 100 years.
• Composition of this concrete is similar to Hennebique concrete used in other countries.

This paper attempts to reconstitute the composition of a type of concrete used at the turn of the 20th century by the Hennebique company, one of the most common reinforced concrete systems used in many countries. This detailed investigation is based on hardened concrete samples removed from a narrow-gauge railway viaduct built in Belgium in 1904. Comparison of these results with quantitative data from other Hennebique projects in Europe suggests that Hennebique used similar mix design everywhere at that time. Moreover, early reinforced concrete aged particularly well due to its (generally) good quality, attributable to the choice of efficient basic materials, appropriate design and workmanship.