Case study – testing of geogrid at Exxaro Coal Mpumalanga and implications for future use

In August 2017 GIBB (Pty) Ltd was requested by Exxaro Coal Mpumalanga to conduct a detail design in order to upgrade one of their existing gravel access roads to surface standard at Matla Mine in Kriel, Mpumalanga. The road is a 1.8 km gravel road that provides access from provincial road R580 to the Matla coal stockpile. This road needed to be upgraded to surface standard in order to accommodate 600 coal trucks per day. Results from laboratory testing showed that the pavement consisted of a G10 subgrade below a 200 mm thick G6 layer which was constructed as part of the mine’s maintenance efforts over the years.