Developing innovative eco-solutions in Doha
Qatar is experiencing a period of great economic development with huge investments in infrastructure and rapid urban development.
This makes the country among the highest per-capita greenhouse gas emitters on the planet. To combine economic growth with human, social, and environmental development, Qatar’s authorities have launched the Qatar National Vision 2030, a national development plan that defines long-term objectives and provides a framework within which the country’s strategies and implementation plans can be developed.
As part of this far-reaching programme, Salini Impregilo is realising the Red Line North Underground in Doha; together with three other metro lines, this project forms part of the city’s new mobility system. The project applies the Global Sustainability Assessment System (GSAS), the Middle East’s first integrated and performance-based sustainability assessment system for the built environment, which is recognised as the most comprehensive sustainability rating system in the world.
The GSAS measures and evaluates every project in eight key categories that have a direct impact on the environment. The system assigns incremental scores to indicate a given project’s successful achievement of environmental improvements. A final certification can be obtained that ratifies both the project itself (permanent works) and the construction activities.
In realising the Red Line North Underground, we implemented a set of innovative solutions to mitigate the project’s environmental impact and reduce our environmental footprint, starting from the type of cement used for the construction of the underground stations. This material is called “green concrete” and is produced by our partner AFRM (Al Falah Ready Mix), whose concrete is the only one approved for use in the realisation of Masdar City (near Abu Dhabi), the world’s first carbon-neutral and zero-waste city.
The “green concrete” was developed to reduce environmental impact to a minimum at all the production phases. Starting from the design of the mix itself, the concrete is composed of by-products from other industrial processes (i.e. waste from the iron and steel industry). This partial substitution of the cement allows for a reduction of cement consumption of up to 70% (while recycling waste from other industries), and a reduction of 50% of the CO2 contained in concrete. For the production of this type of concrete, state-of-the-art plants are used. Totally computerised, they allow significant cuts in energy consumption, the production of returned concrete (3-5%) and wash-out water (10-15%), which is also treated and stored for reuse. As for transportation equipment, 100% of the concrete transit mixers are Euro V compliant, and all the belt conveyors are shielded, reducing sand and aggregate dispersion to less than 1%.
The excavated materials produced on site are moved to storage areas through a shielded conveyor-belt system, thereby avoiding 62,000 truck trips along one of Doha’s busiest thoroughfares, and reducing potential traffic and pollution in the area. The track system will be used for the excavation of the two metro stations in the heart of Doha’s business district. Everything that has been dug out from the two station sites will be recycled and put toward building embankments for a long-distance railway project.
“Nothing will be wasted, nothing will be dumped. We will treat then re-use 100 per cent of this material, which is perfect quality for what we need for the long distance rail construction. I am proud that we are recycling all of it,” Qatar Rail’s Logistics Director Ahmed Al Kowsi added.
Finally, in 2014 we have planned to install a 42 MW tri-generation system capable of producing electricity, heat and cold to be used to power the plants and machineries used at site, which compared with traditional diesel generators, allows for the saving of about 68.8 million kWh per year.
Through these important actions, we contribute to innovate the construction industry in Qatar, fully satisfying our client’s needs and reaching significant results in terms of our sustainability rating.