The first tyre block road in Estonia will be completed in Tapa in June next year, which will address the issue of recycling old tyres. This technology has been in use across the world, including Finland, Sweden, the United Kingdom and the USA for almost 20 years. Now for the first time a similar solution is being implemented in the rebuilding of the Läpi-Ojaküla Road in Estonia that serves as an access route to the central training area of the Defence Forces.
“A new northern section of the road provides access to the Piibe Highway from Ojaküla via Põhja-Kõrvemaa, where traffic would otherwise be restricted when the extended danger zone of the central training area is off limits. New sections are also being added to divert the road away from private residences and ensure that the route is more naturally suitable than it is now,” explained Kaupo Kaasik, Coordinator of Cooperation on Infrastructure Projects at the Estonian Centre for Defence Investment.
According to Sven Sillamäe, road engineer and lecturer at the Tallinn University of Applied Sciences, implementation of tyre blocks will resolve the emerging issue of tyre recycling in Estonia and result in reduced usage in road construction of such unsustainable natural resources as sand and gravel. So some of the soil volume is replaced with a recycled material that can be reused later (when the road is dismantled, for instance) if necessary. Tyre blocks also reduce the weight of the road elements on problematic soil while still ensuring the necessary load-bearing capacity.
Construction of the national defence infrastructure is performed with increasing attention to environmentally friendly solutions. For example, solar panels have been installed on the recently completed army personnel barracks and equipment sheds in Tapa. Besides such buildings, alternative and environmentally friendly solutions are now being used in road construction in the form of underlying tyre blocks.
Old tyres can be used in (road) construction only if this is part of the project design and in compliance with the conditions for safe usage of old tyres. For example, the properties, volumes and application methods of old tyres are defined to minimise their environmental impact.
“Tyres as an inert material are primarily affected by UV radiation, which is why they gradually shed pieces, but this does not happen when they are covered with soil. Scientific studies have shown that some tyre leaching does occur, primarily zinc, but the hazardous substance volumes are low and this leaching decreases with time. That is why it makes more sense to use tyre blocks instead of crushed tyres that are widely used in Scandinavia, as the former will have a smaller surface area, and therefore less leaching,” Sven Sillamäe explained.
The ecological footprint of tyre block production is also much smaller compared to other methods of recycling of old tyres. Furthermore, tyre blocks are priced comparably to other filler materials (sand, gravel) and at some construction locations they can be considerably cheaper. When the road needs rebuilding or dismantling, the tyre blocks will not become waste as they are fully reusable.
The Läpi-Ojaküla Road is being built with a gravel surface that is seven metres wide. The total length of the road is eight kilometres, of which at least three kilometres will comprise tyre blocks. The road rebuilding contract was entered into by the Estonian Centre for Defence Investment, the Tapa rural municipality and the AS Tariston company. The tyre blocks are manufactured by the Wastedirect OÜ company, with the Estonian Environmental Board having already registered this solution and issued a corresponding permit.
“AS Tariston has participated in several innovative projects. This project will provide more experience and boost implementation of innovations. It is commendable that environmental protection goes beyond conversations, with proper steps being taken that facilitate the implementation of environmentally friendly solutions,” commented Aleksandr Lember, Construction Manager at Tariston AS.
“One of the most environmentally efficient ways of recycling old tyre blocks is their usage in road constriction. Tyres affect the environment during daily driving, with tyre particles accumulating on the sides of roads. Old tyres should not be recycled in a manner that creates more waste or hazardous manufacturing byproducts,” commented a representative of Wastedirect OÜ.
Usage of tyre blocks at shooting ranges
Tyre blocks are a financially and ecologically attractive solution for road construction and rural construction on the whole for a number of reasons. They are usually about three times lighter per unit of land than a conventional filler material like sand, thus requiring less transportation capacity. Less filler materials are removed from quarries as a result, thus reducing consumption of natural resources.
Road construction is just one of many tyre block application spheres. For instance, tyre blocks can be used as a draining and water-absorbing layer, reinforcement of slopes, shooting range elements, a light filler material for large-scale filling of problematic soil areas and a filling and reinforcing component of sound-absorbing structures. Tyre blocks are also to be used in the construction of the shooting range impact barriers at the Nursipalu training site.