Construction World January 2017

says explains Bituguard Southern Africa plant manager Caroline Marais. “The strong, three-dimensional network of polymers is impervious to natural extremes of heat and cold. SBS also has excellent aging characteristics. It is not brittle in cold weather and maintains its integrity in hot weather.” The race circuit was completed without any failures and Weideman believes the consistency in all raw materials made it possible to produce an asphalt mix that conformed to all international standards. Hercu du Preez, pavement engineer at WSP Parsons Brinckerhoff, adds that a shuttle buggy was used for all asphalt when paving the track to maintain the integrity of the asphalt mix and achieve the highest possible level of riding quality. A longitudinal indirect joint heater was also used to improve the longitudinal joints. The mix for all non-raceway areas was produced using a 50/70 binder in a Colto Medium design using the specified percentage RA from the milled asphalt on site with great success. Sapref was the bitumen supplier. 

Surfacing of parking areas.

storage tank of an asphalt plant, which can obstruct binder supply to the measuring tank. • Asphalt mixtures may vary in performance. • Hauling the blended product almost 400 km from Bituguard to Much Asphalt’s plant was a logistical challenge. All of these potential issues were

successfully overcome and Bituguard’s good track record on storage stable product and was proven again during this project. SBS modified bitumen SBS is a co-polymer of styrene and butadiene. “When added to asphalt, SBS polymers significantly enhance the performance and longevity of the asphalt,”

33

CONSTRUCTION WORLD JANUARY 2017