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Stronger bond, faster breaking, Shorter closures

In KwaZulu-Natal, South Africa, Colas has recently introduced the Polycol X and Emulcol combination process in order to allow high quality dressing operations during winter periods.

Traditionally, surface dressing operations are performed with hot-applied binders in South Africa during the summer period. During the winter periods the hot-applied binders are not suitable for surface dressing operations.

The contractor, Fynns Construction, working for the KZN Department of Transport, had approached Colas in Durban to perform a trial section, using Polycol X emulsion on road P58 at Izongolweni on the KwaZulu-Natal (KZN) South Coast. In order to minimise production time and limit the time required to allow traffi c back onto a surface dressing, the Durban team decided to use the Polycol X emulsion in combination with the Emulcol process.

The seal consisted of a 13,2mm + 6,7mm double seal covered with a fog spray. The first seal could be broomed after just two hours, and the second seal was sufficiently cured after one hour to allow brooming. The total seal could be completed in one day.

  • 1st spray Polycol X - applied at 1,6 l/m2 at a temperature of 70°C
  • 13,2mm aggregate - spread rate was 0,01m3/m2
  • 2nd spray Polycol X - 1,0 l/m2
  • 6,7mm aggregate - 0,005m3/m2
  • Fog Spray CRS 30 - applied at 0,7 l/m2
  • Intial road surface temperature - 10°C and rising

Both Polycol X emulsion and the Emulcol process are unique to Colas South Africa and give Colas and its customers a strategic advantage in the road construction industry, enabling the company to continue surface dressing operations in the winter months.

The combination of Polycol X and the Emulcol process will allow for considerable cost saving due to increased production rates.