Awards for build quality cast in concrete
THE Concrete Society of Southern Africa has awarded the South African National Roads Agency Limited (Sanral) Eastern Region top accolades for the construction and design of the N2/M41 Mt Edgecombe interchange.
The interchange won the Fulton Award in the main civil engineering structure greater than R100 million category for initiatives where new materials, techniques, technologies, applications, designs and concepts, using concrete as the principal material, have been used and developed.
The interchange is one of the longest structures ever built in South Africa and is being constructed over one of the busiest intersections in the province without closing roads permanently.
The interchange encompasses nine new road bridges, one new pedestrian bridge, nine mechanically stabilised earth walls and three soil nail retaining walls.
Sanral’s Eastern Region also jointly won the innovation in concrete category for the reinforced concrete Van Zyl Spruit bridge, the country’s first “smart bridge” on the N1 freeway between the Trompsburg interchange and Fonteintjie in the Free State.
According to the judges, the interchange – which features three simultaneous incremental launches with a combined deck that exceeds 1.5km – has the longest incrementally launched viaduct in the Southern Hemisphere.
‘It shows that, despite the many challenges faced, it is still possible to produce world-class infrastructure’
“This is a South African first. It was conducted under difficult conditions having to maintain the requirements of the heavy existing traffic demands within a congested site,” the judges said.
The 90m-long Van Zyl Spruit bridge is the first long integral bridge in South Africa and one of the longest integral bridges in the world.
The five-span road bridge has a continuous deck consisting of two spline beams, fully integral with the abutments and piers, eliminating the need for bearings and expansion joints.
The intermediate supports consist of pairs of reinforced concrete piers, one under each spine of the deck and the same width as the spines. The end supports are full height reinforced concrete integral abutments with integral transition slabs.
“The innovative use of integral bridges allows savings in materials, no capital cost for bearings and joints, lower maintenance costs, more durability and makes concrete bridges more competitive,” the judges said.
“The installation of over 500 sensors in the bridge structure, which are being logged automatically every 15 minutes to detect and quantify trends in strain, temperature, tilt and earth pressure, makes this one of the first “smart” bridges in the country.
“The data obtained from these sensors will contribute to a better understanding of environmental loading on the performance of integral bridges and encourage more widespread use of integral bridges,” the judges said.
Logashri Sewnarain, Sanral Eastern Region manager, said the awards were a reflection of the high standard of work on projects and the ability to keep up with evolving economic, environmental and aesthetic demands.
“The award for Mt Edgecombe interchange is particularly significant, because it shows that, despite the many challenges faced, it is still possible to produce world-class infrastructure,” said Sewnarain.
“The accolades are testimony to the fact that we can hold our own in civil engineering excellence when competing in the national and international arenas.”
Sanral also won a Fulton Award in the category civil engineering structure greater than R100m for the Umgeni Interchange project in 2015.