Construction World August 2016

Roadmac Surfacing has deployed three paving teams on this project.

pavement layers involves milling out to a depth of 100 mm and recycling to rein- state a C3 layer to a depth of 250 mm. The 100 mm milled out sections are filled with BTB to original level. Meissenheimer says pavement rehabilitation differs from the other two contracts. On the section closer to Van Reenen, the bituminous pavement layer is milled out to a depth of 120 mm and removed. The C3 layer is 300 mm thick, and the 120 mm milled out sections filled with 80 mm of BTB and 40 mm of TRH8 with modified binder. Extensive repairs are undertaken on the slow lane and involve milling out 65 mm and filling with TRH8 with modified binder. Here, a geotextile is applied after the milling and again in the patch and repair activities, before asphalt is placed. The final surface treatment over the full width sees the placement of a 22 mm thick layer of UTFC. Shoulders are also being reconstructed to tie into the raised final road level. One of the other challenges facing the team has been working on this very busy corridor which cater for total light vehicle traffic of approximately 9 000 per day and approximately 5 600 heavy vehicles a day. Closures on the corridor to accommo- date traffic in a safe unimpeded manner are restricted and have to be carefully managed. Roadmac Surfacing has implemented a novel method of directing traffic in the fast lanes while working on the outer slow lanes allowing ample space for safe and productive construc- tion activities. The low incident and accident count on the three contracts since the start of the project is a testament to the success of the strategy. Meissenheimer has reason to be proud of the performance of the team on yet another project that rein- forces Raubex Group’s ‘blast to black-top’ capabilities.

the Harrismith bypass, Meissenheimer says a 13,2 mm aggregate surfacing seal with rubber bitumen is placed on existing intersections and on the on- and off-ramps. Gravel shoulders will be built up over the full length of the section. Three farm accesses and the inter- section at 42 nd Hill (Verkykerskop) will receive major upgrades to improve the level of service for road users. On the Harrismith bypass section, sections of the southbound and northbound lanes are also rehabili- tated implementing a similar strategy as on the Harrismith to Warden section described above. On the Harrismith bypass section, a 40 mm thick A-R1 overlay is placed over the entire cross-section of the pavement, including the surfaced shoulders of the road. Surfacing, base and sub base patching work is included in the reha- bilitation measures for both sections described above. The Harrismith to Van Reenen section also involves extensive road rehabilitation works, and sees the placement of a thicker overlay due to the impact of higher truck traffic volumes on the road infrastructure. Meissenheimer says on the section just south of Harrismith, the existing gravel shoulders will be upgraded to surfaced shoulders. The top 150 mm is removed and backfilled with imported virgin mate- rial and the recycling is undertaken to a depth of 300 mm and stabilised with cement. A 50 mm thick A-R1 overlay is placed over the entire cross-section of the pavement, including the surfaced shoulders. Rehabilitation Meanwhile, the rehabilitation of the

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CONSTRUCTION WORLD AUGUST 2016