Road rehabilitation on the N12

Part of the newly rehabilitated section of the N12 national route running between Kimberley and Hopetown in the Northern Cape.Colas SA supplied some 3 million litres of Colflex S, an elastomeric polymer modified binder, for all the reseal work that formed part of the road rehabilitation project on the N12 between Kimberley and Hopetown.

This national highway passes through the Northern Cape, close to the Free State border. A previous lack of appropriately timed periodic maintenance had resulted in crocodile cracking, pumping and rutting of the road surface. The required rehabilitation and reseal over 118km of the highway began in June last year and was completed after just more than a year’s work in July 2010.

The South African National Roads Agency Limited (SANRAL) appointed consulting engineers, Aurecon and Tau Pele Construction was the appointed contractor for the project. The broad scope of work called for various pre-treatments of the existing surface and an appropriate bituminous surfacing seal.

Gordon Robertson of Aurecon says, “The existing surface types and condition varied greatly, with predominant distresses being bleeding and, to a lesser extent, ravelling and surface delamination.”

The pre-treatment and intermediate remedial work included: light rehabilitation or in-situ stabilisation of the base layer; patching and crack sealing; asphalt inlays; and slurry surface texture correction, before the final reseal work was done.

For the final wearing course, various chip seal combinations were applied to different sections of the road, using Colflex S throughout as it met the specification for an S-E2 type modified binder. To ensure effective adhesion between the stone and the binder, Colflex S is heated to 180°C before being applied to the road at an ambient temperature of 25°C or above.

Colflex S offers excellent elastic recovery and a high softening point, so the seal will be less susceptible to reflective cracking and bleeding under heavy traffic at the expected high in-service road temperatures. This means the rehabilitated road surface should deliver a longer life in-service, targeted at 10 years.

Previous story
keyboard_arrow_upGreen Star rating courses in November
keyboard_arrow_downGreen Star rating courses in November

In November, the Green Building Council of South Africa (GBCSA) will present the next round of one-day courses on the Green Star SA Environmental Rating System for buildings. This is the last opportunity this year to attend the popular Green Star SA Accredited Professional Course.

Next story
keyboard_arrow_upCall for nominations 2011 Fulton Awards
keyboard_arrow_downCall for nominations 2011 Fulton Awards

The prestigious Fulton Awards are presented by the Concrete Society of Southern Africa (CSSA) every two years to honour excellence and innovation in concrete construction.  The CSSA is now calling for nominations of exceptional projects for the 2011 Awards. The closing date for nominations is 26 November this year and entry packs have to be submitted by 15 January 2011.

keyboard_arrow_upThe Aluminium Federation of South Africa (AFSA) appoints Muzi Manzi as Chief Executive Officer
keyboard_arrow_downThe Aluminium Federation of South Africa (AFSA) appoints Muzi Manzi as Chief Executive Officer

The Aluminium Federation of South Africa (AFSA), is pleased to announce the appointment of Muzi Manzi as Chief Executive Officer with effect from 1 August 2018 following the resignation of Mark Krieg in March 2018. Chairman David Mertens commented: “I’m delighted to announce Muzi Manzi’s appointment. After a thorough search process, the Board came to […]

keyboard_arrow_upYour quartzite questions answered
keyboard_arrow_downYour quartzite questions answered

What can we say about Quartzite? Well, it is a wonderful, hard and strong natural stone ideal for a variety of applications. What is quartzite made from? It is a hard, non- foliated metamorphic rock that was originally pure quartz sandstone.  Sandstone is converted into quartzite through heating and pressure usually related to tectonic compression […]

keyboard_arrow_upCorobrik’s graphite pavers add to the modern Menlyn Learning Hub
keyboard_arrow_downCorobrik’s graphite pavers add to the modern Menlyn Learning Hub

The vibrant design of Menlyn Learning Hub within Menlo Park, Pretoria, has been carefully matched with durable, aesthetically prominent products, among them Corobrik’s latest range of 65mm graphite pavers.