COMSA, through its Technical Area, is leading the European R&D project Life+Gain for the reuse of a type of steel waste, called black slag, in the process of construction and maintenance of railway lines, particularly as a material for subgrade and sub-ballast layers. The application of this waste product in the railway sector is a pioneering activity in Europe given that, to date, reuse has been mainly restricted to road construction.
Black slag, a type of steel waste produced by blast furnaces in the steel industry, is abundant in Europe. According to data from EuroSlag, the European association of producers and processors of ferrous slag, between 8.6 and 14.3 million tonnes of this waste product were generated in 2011 alone. The project, which is currently under way, seeks to extend the use of an environmentally sustainable solution based on the recovery of this abundant industrial waste and, at the same time, to achieve a qualitative improvement over tracks constructed using conventional methods. Its application is expected to reduce the quantity of natural aggregates used for this type of construction and the volume of black slag sent to landfills, as well as reducing costs and an improving the mechanical behaviour of the track.
In fact, research carried out in previous R&D projects, such as ASICAP (steel aggregates in sub-ballast and subgrade layers of railway tracks), also led by COMSA, show that recycled aggregates have better mechanical properties than conventional aggregates, particularly in terms of durability and resistance to wear. And within the next few months, the Gain project consortium will carry out a pilot test involving the use of black slag for the renovation of a 100 metre stretch of the Adif Castellbisbal–Mollet/Sant Fost line to evaluate its behaviour.
The European R&D Gain project is led by COMSA and has a budget of 1.3 million euros. It is envisaged that commercialisation of the project results will commence at the end of 2016.