Ms Sarah Skorpen, a senior lecturer in the Department of Civil Engineering at the University of Pretoria, was the joint winner of the Innovation in Concrete category at the Fulton Awards 2017 for her work on the Van Zyl Spruit bridge. The Fulton Awards are bestowed biannually by the Concrete Society of Southern Africa NPC to recognise and honour excellence and innovation in design and other uses of concrete. The Innovation in Concrete category recognises initiatives in the development or use of totally new materials, techniques, technologies, applications, designs and/or concepts, using concrete as the principal material.

The Van Zyl Spruit bridge was constructed on the N1, near Trompsburg in the Free State, without any expansions joints or bearings. It is the longest integral bridge in South Africa, measuring approximately 90 m in length. Ms Skorpen, working with technicians Mr Rikus Kock and Mr Sarel Coetzer, and with Prof Elsabe Kearsley, equipped the bridge with instrumentation to measure approximately 500 channels for the South African National Roads Agency SOC Ltd (SANRAL).  

The instruments include strain gauges to measure strains in the bridge deck, as well as temperature sensors, tilt meters and earth-pressure sensors behind the bridge abutments. Furthermore, a pilot study is being undertaken on the bridge, in collaboration with the Cambridge Centre for Smart Infrastructure and Construction, to test a fibre-optic strain measurement system. Fibre-optic strain measurement allows strains to be recorded with unprecedented accuracy and resolution.

Data from the instrumentation system is continuously recorded and relayed to the Internet from where it can be downloaded by researchers. The data will reveal how long integral bridges will behave under South African conditions, where temperature variations can be significant and the climate is very dry. The benefits of this research will lead to a better understanding of the behaviour of integral bridges and hopefully the wider use of integral bridges in South Africa, thus saving employers ongoing costs, especially for bearings and joint maintenance over the life of the bridges.

This project demonstrates how civil engineers can benefit by applying the latest technology to learn about the behaviour of unusual structures, allowing designers to design these structures with more confidence.