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JSC “Latvia's State Forests” and Riga Technical University Scientists are Working on a New Technology for Dedusting Gravel Roads

JSC “Latvia's State Forests” (LVM) is among the largest road managers in Latvia. The network of forest roads, which reaches almost 13 thousand kilometres, plays an essential role in ensuring successful forestry; moreover, forest roads are also actively used by residents to get home or relax in nature. At the request of LVM, scientists from the Department of Roads and Bridges of the Faculty of Civil Engineering of Riga Technical University (RTU) and the Institute of Polymer Materials of the Faculty of Materials Science and Applied Chemistry are researching a sustainable new lignosulfonate-based dust removal agent suitable for the Latvian conditions.

“LVM, as a State forest manager and road owner, has to take care of the impact of forest roads with gravel surfaces on people, because summers are getting longer and drier and people have become more mobile and, thanks to remote work opportunities, many choose to live in homesteads, which are often located relatively close to forest roads. At the same time, people have become more demanding about the quality of the living environment, especially when it comes to the outdoor space around their residence. We are pleased with the work done by the scientists in this research project, because we will be able to easily and effectively implement the results in our everyday life, and it should be especially emphasized that this product is not obtained from fossil raw materials, but rather from our own renewable resource grown in Latvia – wood, leaving as little impact as possible to the surrounding environment,” says Ingus Barviķis, LVM Forest Infrastructure Operations and Maintenance Manager.

In a laboratory study, scientists determined the properties of lignosulfonate from different suppliers, experimented with its concentration, viscosity, application method, performed ageing to find out how long the dust remover based on lignosulfonates would withstand ultraviolet radiation and high air temperature. This is how a technology optimal for the Latvian conditions has been found. Laboratory confirmed its effectiveness in hot and dry summer periods – after application on a forest road, the dust remover retains its properties for several months, when it is applied again, a smaller amount is required.

“Calcium chloride is traditionally used for dedusting gravel roads, it binds air moisture during the night hours so that the road surface does not dry out so quickly during the day. It is a good and effective tool, but the forest ecosystem is sensitive; therefore, traditional dust removal solutions cannot always be used on forest roads. Lignosulfonate is a biobinder that “glues” dust together, preventing it from rising into the air,” says Viktors Haritonovs, Leading Researcher at the Department of Roads and Bridges of RTU.

The technological process, which was tested by scientists in the laboratory, was transferred to real conditions last week. In the vicinity of Plakanciems, a three-kilometre-long forest road was dedusted. The RTU researcher explains that the experimental route is divided into 15 stages, using different combinations of the dust collector. To be able to compare, calcium chloride was also applied in one stage, and a mixture of calcium chloride and lignosulfonate in another. In the future, it will be monitored how the road serves, whether and how quickly the dust remover washes out, under which conditions it has the highest efficiency.

This week, it is planned to implement a similar road treatment around Ķegums on the Abermaņi road. The aim is to compare the effectiveness of the applied means at higher transport intensity and different road surface material. Different weather conditions are also an important factor.

The project was implemented in cooperation with the State Institute of Wood Chemistry of Latvia, JSC “Latvijas autoceļu uzturētājs” and LLC “Ceļu eksperts”.