SAT was pleased to present to industry the Third Edition of TG2 for BSMs, incorporating 18 years of experience and new technologies. The first TG2 guideline was published in 2002 for foamed bitumen only and the Second Edition for BSMs in 2009.

This technology has now been implemented globally and the manual has been assembled using evaluation data from abundant project investigations and long-term pavement performance records. This has allowed the DEMAC materials classification system to be updated, mix design procedures to be overhauled and refined, and the Pavement Number method to be updated. At the same time, a mechanistic design function has been developed for BSM pavement structures.

Sasheen Rajkumar provides a global and local view, starting with a definition of RA and the historic context. He goes on to detail the asphalt recycling process, mix types, influencing factors, and issues around quality. What are the environmental and economic benefits and, importantly, the regulations around ownership and disposal of RA?

There are various mixing plants with different capabilities that can be used for asphalt mixes incorporating RA, as well as recycling batch plants. Herman Marais provides the information you will need. While the same basic types of mixing plants are used, modifications are required, and standard plants should not be used to produce asphalt with high RA content.

How to design a mix using RA – this paper has it all. Learn about mix selection from types to design considerations, getting the proportioning of new aggregate, new binder and RA right, tests to be conducted on RA samples, and the use of rejuvenators. Wynand Nortje closes off with advice on testing of the recycled asphalt mix.

Greg Reynolds details all the steps from milling and stockpiling to processing and optimal use of reclaimed asphalt.

Steph Bredenhann summed up the Winter Seal Workshop held by SAT in April 2014 with some thoughts on the current scenario at the time and the way forward. For him the important steps in the success of winter seal applications include sharing of knowledge, planning, and attention to detail, bearing in mind that this is not an exact science. He also maps out a brief strategy for the future.

Dennis Rossmann drives home the importance of an advance QA plan to agree responsibilities and verify sampling procedures. He goes on to list tests envisaged for all sealing and the differences to be aware of for winter sealing.

This presentation covers the essentials of binder testing in winter seals, with focus on the properties of cutback binders used in cold temperatures in South Africa, the rheological effects of adding paraffin, site testing including getting cutter quantities right, gas chromatography and mass loss. Also get the lowdown from Johan O’Connell on evaluating the curing rate of winter seals.

Kim Jenkins talks us through the key factors, including various test results that help practitioners to make informed decisions. The presentation touches on bitumen specifications and performance grading, BBS tests including adhesion/cohesion factors, hot applied binders versus emulsions, the influence of precoat, manufacturing temperature and more. Well informed decisions can be made when selecting materials for surface seals if BBS properties are known, Jenkins concludes.