R20 million will be invested into maintaining and upgrading bridges across Johannesburg. This will be undertaken by the Johannesburg Roads Agency (JRA) and forms part of its maintenance plans for the city’s transport infrastructure.

The funds will be used in the replacement of bridge expansion joints, which Mpho Kau, head of infrastructure development at the JRA, says “plays a vital role in the maintenance of the city’s bridges”.

“Bridges are designed to allow for movement within predefined limits,” Kau says. “The increase in traffic, environmental factors and accidents has a severe impact on the rate at which bridge components deteriorate.”

Therefore, he says the JRA carries out routine and scheduled inspections for the implementation of maintenance, repair and rehabilitation to preserve the city’s existing transport infrastructure.

The JRA said the rapid expansion of the city over the last 50 years has had a severe impact on the city’s aging infrastructure. This has been due to an increase in road traffic across the city and its growing population.

Older bridges therefore require continuous monitoring and planned inspections to ensure their structural integrity, the JRA explained.

Kau explained that bridge expansion joints are designed to allow for continuous traffic between structures while accommodating movement, shrinkage/expansion, and temperature variations on reinforced and pre-stressed concrete, composite, and steel structures.

“They stop the bridge from bending out of place in extreme conditions,” he says. “In bridge construction there are various types of expansion joints, which can accommodate movement range from 30mm to 500 millimetres.”

Kau said the replacement of 42 expansion joints were completed on 16 bridges as part of the JRA’s 2016/2017 infrastructure and planning budget.

A total of R14.4 million was also spent on the replacement of expansion joints on the listed bridges:

1. Anerly Road Bridge over the M1
2. Ballyclare Drive over Braamfonteinspruit
3. Jan Smuts Avenue River East
4. Melrose Street Bridge
5. William Nicol Bridge
6. Olifant Road Bridge
7. New Canada Road near Main Reef
8. New Canada Road over N17
9. Buccleuch Drive Over River
10. Rabie Street Bridge
11. Mangaan Street Bridge
12. Main Reef near New Canada Road
13. Main Reef near Turbine Road
14. M1 near Joe Slovo
15. Conrad Drive Bridge
16. New Canada Road near Railway