Technology transfer of large aggregate mix base [LAMBS] on Johannesburg roads.

Abstract

Research on Heavy Duty Asphalt Pavements [HDAPs] was conducted by the CSIR Division of Roads and Transport Technology on behalf of the South African Bitumen and Tar Association [SABITA]. This research soon focused on Large Aggregate Mixes for Bases [LAMBS] for which new mix design procedures had been developed. An early focus of this research was the constructability issues associated with this road building material. The superior performance of LAMBS was validated by means of accelerated road tests done by the Department of Transport. The need for structural strengthening of the M2-Motorway in Johannesburg during its rehabilitation afforded opportunity of transferring the technology to the road construction industry. LAMBS were selected as it was cost-effective and had proven bearing capacity under high traffic volumes and heavy axle loads. LAMBS were exposed to very heavy traffic on the M2-Motorway without any problems before it was overlaid with a final surfacing.