In Lithuania, slag was used for road construction for the first time
A unique section of road in Jurbarkas district, in the construction of which slag generated after the conversion of non-hazardous waste into energy was used, was completed. It is the first project of this kind in Lithuania. Its purpose is to analyse the road in detail and determine the impact of slag on road operation. After completion of research and after evaluating the results achieved, it will be possible to decide on the further use of slag on Lithuanian roads.
9,000 tons of slag, that was generated at UAB Gren Klaipėda power plant of waste conversion into energy and that was prepared for the use, were used in the one-kilometer-long test section of the road. The project was ordered by the State Enterprise Lithuanian Road Administration, the contractor – AB Kauno tiltai, and analyses during the installation and operation of the road are carried out by the Public Institution Vilnius Gediminas Technical University (VILNIUS TECH).
The exact location of the experimental section – between the kilometres 1.8 and 2.8 of the district road No 1705 of the national importance in Jurbarkas district, that connects Mikutaičiai I and Vertimai villages. 5 experimental coating structures were installed in this section. The project is being implemented in two stages. Stage 1 – the installation of an experimental section, stage 2 – assessment of the possibility of using slag on the road with the help of installed sensors. The second stage will last until April 2024. However, hopefully, it will be possible to see the results of the operation of the road section already after the first or after two winters.
‘The first test that is being carried out in Lithuania – to use in the construction of roads a slag generated during the incineration of non-hazardous waste – is an excellent example of the implementation of the principles of the circular economy. If the experiment will prove its effect, we would reap the full benefits – the environment would be cleaner, and we would have a recycled raw material obtained in Lithuania for the development of the road infrastructure. This would be a new step in the transport sector, which opens up wider perspectives on the use of environmentally sustainable materials in road construction’, – says Marius Skuodis, Minister of Transport and Communications.
In September, the Ministry of Environment approved new requirements for the handling of ash and slag. These requirements allow the use of a slag remaining after incineration in road construction, installation of building foundations, to cover the layers of waste being disposed, in closing landfills and constructing temporary roads there.
Simonas Gentvilas, Minister of Environment, hopes that if the experiment will prove to be successful, it will be possible to use in the future for road construction all the secondary raw material generated in the country – ash and slag, which will replace the granite, that is normally imported. “I ask the drivers, who are driving through Vertimai village, to pay attention to the fact that professionals have turned this section of the road into a road using the material that was once our waste. The use of ash and slag enables the creation of new value instead of transporting useful material to landfills to no purpose”, – says the Minister of Environment.
According to Remigijus Lipkevičius, Director of the State Enterprise Lithuanian Road Administration, in the case of positive test results and after finding that the proper nationwide use of slag generated in waste incineration plants is possible in Lithuania, quantities of slag to be disposed and its disposal costs could decrease.
According to Vitalijus Žuta, CEO of UAB Gren Lietuva, this is another long-awaited stage in waste recovery. “Since when the first in Lithuania waste-to-energy plant in Klaipėda started to operate, we have worked actively and consistently to achieve the recognition of slag as a useful material and that it is not discarded but used. During that time, together with various departments of Vilnius Gediminas Technical University, we conducted five long-term studies, and we have proven that our slag is a reliable and useful material. This has become a reality in this project”, – said Vitalijus Žuta.
Currently, three waste-to-energy plants operate in Lithuania. Their total capacity is 615 thousand tons of waste per year. After recovery of energy, that is, after the waste is incinerated, about 20% of this amount falls out in the form of slag. Thus, about 120 thousand tons of slag per year are generated in Lithuania. Slag is generated by incineration of non-hazardous waste at a high temperature of about 1000oC. It is a hard material in the form of a porous stone.