Paving the way for Future: How road construction is becoming more sustainable – Part 1
At the very core of how we live, work and commute in our daily life lies the global road network. It is perhaps the single largest system ever built by man. However, it is the very scale of this network that has over the years become one of the largest contributors of greenhouse emission of all human endeavors. Though the road types may vary based on location, purpose and method of construction most of the materials used still remain crushed rock, sand and asphalt. With the need for sustainability becoming more defining there needs to be a change either through the fossil energy consumed during the construction process or through a shift in materials utilized.
It’s not that the philosophy of sustainability is missing in the construction at large, in fact it has been widely adopted by many areas with the most notable being commercial architecture. Many AEC firms have managed to utilize modern technology to implement renewable energy systems, make use of green building materials or successfully used BIM Services in the planning stage for better administration of resources and reduction of waste.
The road construction industry however has a long way to go. The highway agencies and engineers are gradually rising to the occasion by actively looking for innovative designs and practices to meet this new objective. Greenroads are quickly becoming the solution that they were seeking. These are roadway projects that have been designed and constructed to a considerably higher level of sustainability than what is the customary practice. Below we identify three innovative approaches that will perhaps be a common practice in the future.
1. Material Selection:
In order to noticeably reduce the carbon emissions, the major contributing factor will have to evolve to become more sustainable. This means a change of the materials that are used in the process of road construction. The new materials will not only have to benefit the environment but also work at being stronger and lasting. There are a lot of developments taking place across the world but the below three materials and their pioneering way of use has gained prominence:
- Recycled Plastic Roads:
The use of post-consumer plastic waste to build more sustainable roads not only replaces the more finite materials of road construction but also reduces plastic pollution along the way. This process of using melted plastic to fill potholes has been prevalent in India for many years but it was the British who took it one step further. British Engineer Toby McCartney developed a method of converting plastic bottles into small pallets that could be added into the asphalt mix. In every kilometer of road construction approximately 10 tonnes of asphalt is utilized. This technique allows to mix 3-10 Kilograms of plastic waste in every tonne of asphalt. This not just increases the bulk but also makes the roads 60% more stronger and 10 times more durable.
- Refabricated Plastic Roads:
One of the properties of plastic is that it is virtually impossible to dispose of but this very property could also be useful to increase the resilience of roads. A Dutch company has used this to develop plastic roads. These are prefabricated modular roadways made completely recycled plastic. By using plastic, the road expectancy can be increased by 2-3 times than the conventional roads. It has also taken away the frequent hassle that goes into maintenance of roads . These roads are designed in a hollow manner which also allows the service pipes and cables to feed through the road desk and removes the need to dig deep into the Earth’s surface. Also, these materials are four times lighter and around 70% faster to transport. Thus, there is also a reduction in time and resources that are spent in transportation and installation of roads.
- Solar Roads:
Incorporating solar panels into the road system is a way to convert a static piece of infrastructure into a major source of renewable energy. Many road construction companies in Europe and USA have developed prototypes which have the strength needed to witness heavy traffic and a long life expectancy. But for experts there are some hesitations about the vehicles driving over the toughened glass or silica which is required to protect the photovoltaic elements of these solar panels. Additionally, the question does remain about the effectivity of these horizontal solar panels in comparison to diagonal solar panels. However, research is constantly being done and we might find solar roads in a street nearby very soon!
In the next article we will continue to discuss what more is required to create sustainable roads. We will talk about construction methodology and how the key benefits of Virtual 3D Modelling like BIM Coordination, Clash Detection etc. will benefit the engineers. We will also shine a light on how Scan to BIM services can be used for the reconstruction of old roads.