RMK tests oil shale ash for forest road construction 24.08

Forest roads are not used frequently, but they still need to be of good quality and have a high load-bearing capacity. For these reasons RMK is constantly looking for new ways to make roads of better quality whilst reducing environmental impact.

"For decades now we've been using leftover limestone from quarries and rubble made from it to construct forest roads," said Margus Reimann, the Head of the Forest Improvement Department at RMK. “We also use geosynthetic materials to extend the lifetime of roads and use less road surface material. “Now’s the right time to start using oil shale ash, of which there’s tonnes left over from the oil shale industry, so as to waste less gravel."

The first 1.3-km section of road for testing the new material was completed in the village of Viluvere in Põhja-Pärnumaa municipality in Pärnu County, where an existing dirt road was treated with oil shale ash. 35 kg of ash was used to treat each 25-cm deep square metre of the road. According to Reimann, RMK constructs and repairs more than 300 km of forest roads per year, requiring between 600,000 and 700,000 m3 of gravel. As such, if RMK is able to use 10% less road surface material, they can reduce the carbon footprint of their transport by 100 tonnes per year.

"Construction of the road has been completed, but we now have to wait for the ash to harden," explained Reimann. "RMK will test the road in October or November by transporting wood from a nearby cutting site to evaluate the quality of the road’s surface material and to establish whether its bearing capacity meets our expectations."

There are plans to treat a further two roads with oil shale ash next year, this time in Ida-Viru County: one a dirt road with a coal stock surface and the other a clay dirt road.

TTK University of Applied Sciences also involved in the pilot project, conducting testing in its lab and monitoring the state of the roads once completed.

Oil shale ash has previously only been used in Estonia to stabilise state roads, but it is widely used in Poland.

The organisers of WRC Rally Estonia also noted the quality of RMK’s forest roads, which is why some of the speed tests for this year's event are being held on state forest roads.

Browse RMK's Flickr albums for photos of forest road construction.

Additional information:
Margus Reimann
Head of Forest Improvement Department, RMK
E-mail: margus.reimann@rmk.ee
Mobile: +372 50 21 510

Sille Ader
Head of Communications Department, RMK
E-mail: sille.ader@rmk.ee
Mobile: +372 5666 5896