2011_AAPA_Study_Tour.. - Aapaq.org

4. Surface Treatments Questions and Responses AAPA 2011 Study Tour Group Report4. SURFACE TREATMENTSWorking GroupLeader: John EsnoufTour scopeV4-2 Page 10Group: Robert Busuttil, Kym Neaylon, Trevor DistinSurface treatments – Use of spray seals under heavy traffic, Crumb Rubber Binders, Alternatespray seal configurations, Low cost sand seals on low traffic roads, Surface rejuvenationtreatmentsFeedback from• SANRAL Western Cape• SANRAL Head Office Pretoria• SANRAL KwaZulu Natal• University of Stellenbosch• CSIR Built Environment• eThekwini / Durban Municipality• Colas South Africa• Tosas binders division of Sasol• Gerrie Van Zyl, specialist spray seal consultantObservationsSouth Africa, like Australia is large country with a relatively low population density. Thin surfacingtreatments combined with granular pavements are used extensively as an economical means ofproviding an all weather road network. This is reflected in the fact that 90% of South Africa’ssealed network is sprayed sealed.1. Maintenance programmingWhile there are similarities with Australian practice local issues and experience have resulted inseveral different sealing configurations and techniques being adopted, these include triple seals,cape seals and emulsion fog sprays. Of most interest was the use of sprayed seals under heavytraffic conditions.Differences also exist in the way that the sealed network is allocated and managed betweenMunicipal (Council), Provincial (State) and National (Federal) road authorities. Unlike Australia,national roads are managed directly by the South African National Roads Authority Ltd. (SANRAL).This is an independent statutory authority owned by the South African Government(www.nra.co.za).