THE USE OF SBS MODIFIED BINDER IN THE RESEAL OF NATIONAL ROUTE N2/27 AND 28: NEW GUELDERLAND TO MTUNZINI

In the continuous endeavour to develop surface seals capable of withstanding the high traffic volumes on some the country’s National routes, numerous surface seal design approaches including the use of modified binders are being considered. Bituminous binder modification represents an important option to obtain surface seals with improved performance characteristics. This paper describes the application of a SBS modified binder in the construction of 60 km of a double seal on the four lane undivided section of the N2/27 and 28 between New Guelderland and Mtunzini on the KwaZulu Natal north coast. A SBS modified binder, conforming to the SE-2 specification was specified for the double seal on the shoulder and slow lane, with the fast lanes receiving a double seal constructed with an unmodified binder. This paper will report on the binder rheological properties measured from production through to the application stage as well as on the environmental factors influencing the application of this highly modified binder in the construction of the seal. A comparison of the production and application of the two different types of binders will be reported on.