CMA MEMBERS MAKE SUBSTANTIAL CONTRIBUTION TO GFIP:

The R15 billion project comprises 15 work sections or work packages as they are referred to by SANRAL (South African National Roads Agency Limited) and cover a total distance of 185km. The upgrade entails work on the whole N1 from Soweto to the N4 just north of Pretoria and the whole N3 from Voslorus to the N1 at Buccleuch. It also involves improvements to the N12 from Tom Jones Street in Benoni to where it joins the N1 at Soweto, as well as the R21 from Pretoria to Boksburg.

The project entails widening existing stretches of freeway from three to four lanes in certain sections and up to six lanes in others, for instance between Buccleugh and Allandale. It also includes capacity upgrades at the interchanges as well as additional turning lanes, new bridges and the doubling up and widening of existing bridges.

Some interchanges are being completely revamped and are being converted from diamond layout systems to single point systems, while others involve the widening of bridges and wider on-and-off ramps. Acceleration and deceleration lanes, 300m to 500m long, are also being built to facilitate safer entry and exiting of the freeway system.

SANRAL project manager, Hennie Kotze, says given that the space for staging and shuttering support is often extremely limited, the use of  precast concrete elements such as beams on bridges has been indispensable to the upgrading process.

“Existing storm water pipes and box culverts have had to be extended under the freeways, and in instances where new interchanges are being built, new culvert and storm water systems are being installed,” comments Kotze.

Different types of precast concrete barriers are being used on GFIP, some of them as temporary barriers for traffic control. Precast concrete panelling is also being used for embankment reinforcing and facades.

For instance, panels 800mm to 4 900mm long and 1 980mm wide are being used for the protection and aesthetic enhancement of several embankments and cuttings on the N1 freeway between Atterbury Road and the R21 interchange. Precast concrete barriers, 1m high, abut the panels at ground level, securing them firmly in position, and as a finishing touch, precast concrete coping panels have been installed at the upper end of the structure.

Precast concrete beams are being used on some of the bridges and these vary from smallish I-beams to huge U beams weighing up to 70 tons.

Storm water concrete piping, 1 350mm in diameter, is installed under a section of the N12 west-bound freeway in Gauteng.

A 1 500mm diameter manhole near the switch ramp on the N3 north near Alberton.

A box culvert, partially obscured by loose rock, seen here at Reading interchange on the N12 freeway.

Storm water pipe sections, 1 350mm in diameter, prior to installation near the switch ramp on the N3 freeway.

Concrete façade panels 800mm to 4 900mm long and 1 980mm wide are being used for the protection and aesthetic enhancement of several embankments and cuttings on the N1 freeway between Atterbury Road and the R21 interchange.  On this stretch of south bound freeway, the panels reach their maximum height. Concrete barriers, 1m high, abut the panels at ground level, securing them firmly in position.  Coping panels installed at the upper end of the façade panels add the finishing touch.

Concrete façade panels 800mm to 4 900mm long and 1 980mm wide seen here at a section of the new Atterbury Road/N1 interchange in Tshwane. The panels are being used for the protection and aesthetic enhancement of several embankments and cuttings on the N1 freeway between Atterbury Road and the R21 interchange.

DATE September, 2009
ISSUED BY David Beer Communication Consultants
FOR  Concrete Manufacturers Association 
ENQUIRIES John Cairns (011) 805 6742
David Beer (011) 478 0239 cell 082 880 6726  Email: bigsky@ibi.co.za