Abstract:
The SANRAL funded research on unconventional soil stabilisers identified Nano Modified
Emulsion (NME) as effective and viable natural soil and gravel stabilisation options. The
inclusion of NME in the new Draft (2022/23) TRH 24 established NME technology as cost
saving option to upgrade low traffic volume gravel roads to surfaced standards. NME
treated material makes natural or marginal quality granular materials water proof and
flexible versus the negatives of cracking and potential crushing of cement treated material.
A Community Development Project (CDP), linked to the current SANRAL upgrade and
special maintenance contracts on the R504 (Wolmaransstad to Leeudoringstad and to
Bothaville) offered an opportunity to do upgrades to various streets. A budget of
R30 million was set aside for such CDP street upgrade and rehabilitation of selected badly
deteriorated streets in these towns. A variety of NME technologies were designed for
implementation. The traditional single seal or Cape seal was used as surfacing on the
surfaced streets. Cement treated base type construction was also done for comparative
purposes as well as gravel preservation treatment of some lower traffic volume streets.
There are various lessons learnt by the collective team involving client, consultant and
contractor plus community based local contractors as sub-contractors.
