How to find the optimal balance between the economic and ecological components of road construction
Road laying is known to impact on nature, sometimes dangerously. For decades, society has been looking for ways to harmonise the interrelation between the road construction industry and the environment.
Grass does not grow on a broken road
The modern transportation system has long been recognised as one of the main ecological threats on the planet due to a lot of different phenomena, including emissions that are dangerous to the biosphere, the fragmentation of ecological zones causing harm to animals, and waste products that are harmful to soil. All these factors result in great economic losses and impact on the quality of human life.
The air environment is considered to be the most vulnerable. Following research, scientists discovered a direct relation between the qualitative composition of the air environment and people’s health.
Air pollution and frequent fogs block the necessary amount of sun rays we require. In relation to this, such contamination in Moscow is 10—13% higher than in the suburbs. In general, a huge amount of transport in the central districts of large cities where the wind speed and solar radiation is 15—20% lower prevents the air from self-cleaning.
According to Valery Vakulenko, Member of Board of the Ecological Construction Council, automobile transport in Russia is one on the sources of the complex negative impact on the biosphere and human health. Almost 40% of the total anthropogenic air pollution belongs to this industry. That is why it is so important to plan cities and their infrastructure carefully.
There is no general opinion about the most harmful road factors. Some experts stand by the euro-standards for fuel, while others remark that pollution from the particulate emission of car tyres is 26-fold higher, and of cargo vehicles it is 100-fold higher. What is the reason for this? The answer is simple and only due to the low quality of tyres and road surfaces.
As soon as a road is put in operation, due to mechanical damage and general wear, and as a result of diffusion, particles of road covering converge with the lower air streams.
Additionally, this results in plumbum and other heavy metals setting on vast territories along the roadside. Unlike air and water, the process of self-purification of the soil is very slow.
Continuous building has resulted in deforestation
Spontaneous picketing has developed in the Stepnoy district of the Russian city of Orenburg. People are protesting against the deforestation connected with the construction of a new road. They decided not to wait until one of the ecological zones, already rare for this city, is destroyed and stood in the way of builders.
Unfortunately, the end result is predictable. According to Rita Goncharova, Head of the Construction and Road Industry Department of the Orenburg administration, the new road will be built despite all the protests of the population. This is especially because it is the continuation of an unfinished construction which was frozen due to the money running out. 300m roubles are allotted for the construction of 1.4 rm of the road. This means that while people are struggling against it, the road builders are continuing according to their plan, which is to put the road in operation by the end of 2017.
Another example is the struggle for the Khimki forest, which was at the centre of a massive demonstration since the moment the project of the M-11 Moscow — Saint-Petersburg express highway construction was first adopted. Though the road was built, the effort of those who defended the forest was not in vain and the forest was saved: instead of 100 deforested hectares 500 hectares were planted with trees. Additionally, the unprecedented sum of 4 bln roubles was paid in compensation for the ecological damage.
However, social and economic progress demands the development of the infrastructure. The construction of a road should be considered in great detail at the design stage, taking into account all the possible prospects and conditions.
Looking for synergy
One of the main tasks of road construction science is to increase resource and energy efficiency on the basis of the correlation of economic and ecological components. It is not easy to find a balance as the reserves of the industry are not fully used.
Special attention should be paid to the use of industrial by-products of natural origin in road construction.
Such material as pine tar, used as a plastifying and emulsifying addition to viscous petroleum asphalt, makes it possible to significantly decrease the resource capacity of the materials and to save on the budget.
Despite its availability and relative affordability, however, pine tar is not used efficiently enough because there are no technologies available that are economically based and ready for industrial implementation.
Meanwhile, the wood-pulp and paper industry flooded the market with one of the most widespread organic polymers, woody lignin. It contains 30% of non-fossil organic carbon. The unique performances of this material are used in the USA for decreasing the level of road dust and gravel stabilisation on unsurfaced roads. It also provides a higher quality of asphalt concrete and increases its strength by 25%, its resistance to cracking from -15°С to -25°С, and its waterproofing quality by 13%. Additionally, lignin makes it possible to save on road construction materials: oil bitumen by 16—21%; and mineral powder lime by 100%, plus helps the recovery of good soil.
The use of geotextile and biofiber also adds to ecologically safe construction.
These materials, used for ground stabilising and strengthening the structure of the road surface, are very prospective from the point of view of their energy efficiency and decreasing the harmful impact on the environment. They also help with minimising the dependence on the cement and petrochemical industries.
Geotextile makes it possible to increase the thickness and the quality of a road surface several-fold, and besides this the technology of its laying is very simple once one knows the peculiarities of the material.
And, indeed, let’s discuss miracles a little. The use of nano-techologies is a mainstream priority for the road construction policy in Russia. The advanced technologies increase the serviceable life of asphalt by 30—50%. Rutting resistance increases by 25—30%. Inter-maintenance periods increase two-fold, and the estimated cost is reduced by 40—50%.
All these figures prove the necessity for the advanced development of road construction science, and a systematic approach to the adoption of efficient laws and the use of the updated technologies.
However, presently, the interrelation of the economy and nature resembles a marriage of convenience where divorce is unacceptable, despite life being full of unavoidable conflicts. Under such conditions, it is very difficult to successfully solve the issues concerning ecologically safe road construction. The road industry is likely to take the innovative way of development only on condition of taking efficient measures to increase ecological and resource safety.