PRELIMINARY AND DETAILED ENGINEERING DESIGN, CONSTRUCTION SUPERVISION OF IMPROVEMENTS AND REHABILITATION WORKS FOR THE ROAD N12-19 : GILLOOLY’S INTERCHANGE TO RIETFONTEIN (R21) AND PORTIONS OF THE N3-12 NORTH BOUNDI
National Route 12 Section 19 and National Route 3 Section 12 are located in Gauteng province and traverse an entirely developed urban terrain in the Ekurhuleni Metropolitan Area.
N12 Section 19: This section extends over 10,60 km from Gillooly’s I/C to the Rietfontein (R21) I/C in Boksburg. The N12 section from Gillooly’s I/C to Electron I/C consists of five lanes per direction. The major work included the strengthening of the pavement by replacing the existing asphalt with a continuously reinforced concrete pavement. A new directional ramp in the Gilloolys I/C was constructed to improve traffic flow from the N12 (Boksburg) to the N3 (Sandton).
The section from Electron to Rietfontein interchanges consists of three lanes in both directions which are upgraded to four or five lanes per direction. The inner lanes are constructed with the newly developed ultra-thin continuously reinforced concrete pavement and the outer lanes with a traditional continuously reinforced concrete pavement. Three access interchanges were upgraded with additional lanes in certain locations. The above work required the widening of a number of structures and new retaining structures. Three bridges were raised in-place to increase the vertical clearances to minimum standards.
N3 Section 12: This section extends over 6.8 km of the northbound carriageway from Gillooly’s I/C to the Modderfontein I/C. The major work on this section entailed road widening with related bridge widening and retaining structures.
The entire project received an asphalt overlay, new road signs, highway lighting, and various other ancillary works for the improvement of the road.
The project included upgrading works under Double Bituminous Surface Treatment, and rehabilitation and widening works of urban roads.