OHLA subsidiary uses new environmentally sustainable blends, driving innovation in its business

Elsan completes pavement rehabilitation works within the framework of the Endreça Plan of the Barcelona City Council

May 9, 2024

Elsan, a subsidiary of OHLA specialized in urban, road and infrastructure services, and an expert in the research and development of asphalts, bituminous blends and sustainable road surfaces, has completed the pavement rehabilitation project in Vía Júlia, Barcelona. The initiative is part of the City Council’s Endreça Plan and involves Elsan’s application of two new environmentally sustainable blends, the result of Elsan’s quality control laboratory and R&D+i work, accredited by the Ministry of Transport, Mobility, and Urban Agenda in the General Registry of Testing Laboratories for Building Quality.

The first of the blends used is an AC22BIN 35/50S 20R, designed and manufactured with a 20 percent rate of reclaimed asphalt from milling operations, reducing the use of virgin quarry aggregate. This mixture has been placed in the intermediate layer of the pavement package, as reinforcement for the most deteriorated areas of Vía Júlia.

The most innovative area in terms of design is the second mix. It is an SMA11 for wearing course in which, as a first innovation, it has been manufactured with 100 percent of its aggregates of iron and steel origin, both the fine and coarse fractions. This type of aggregate, valorized and supplied by Adec Global, is considered a waste from steel mills, which confers a high sustainability value in relation to the environment.

This mixture, included in the Elsansono project, incorporates in its manufacture, as a second innovation, pretreated rubber powder from the collaborating company Tyre Recycling Solutions (TRS) which, together with a granulometry with a higher than normal content of voids in the mixture, reduces rolling noise and improves the quality of life of the neighbors in the area.

As a third innovation, the incorporation of rubber powder at high rates (one percent of the mix), and the use of a conventional bitumen type 35/50 in the manufacture of the mix will extend the useful life of the mix over time.

The latest and most sustainable innovation has been the manufacture of the mixture at low temperature, which significantly reduces CO2 emissions into the atmosphere, a consequence of Elsan’s commitment to the environment.

Elsan, a trajectory linked to innovation

These new road pavements are in addition to other recent reference projects in which Elsan has shown its research character and its constant commitment to innovation in the field of sustainable road pavements and bituminous mixes. The Elsansono project stands out, focused on the development of bituminous mixtures for wearing courses. This sound-reducing asphalt reduces, thanks to its high void content, the high decibels produced by road traffic.

Another initiative developed by the OHLA subsidiary is the Ecosurf Project. Its origin lies in the study of milled materials and new binders that allow designing high-performance discontinuous bituminous mixtures like BBTM with a 30% recycled material rate and with the same durability as a conventional mixture without recycled material. Also, the Siderar project, based on bituminous mixtures for base and intermediate layers with steel sand, impacts the reduction of raw material costs while promoting the circular economy through the use of recycled materials.