Red, sustainable asphalt
In the town of Eindhoven, a road was recently constructed of red asphalt with 40 percent recycled asphalt, a material specially developed by KWS. The sustainable mixture is produced with green gas and supplied and processed under CE certification. Due to the high percentage of recycled asphalt, fewer primary raw materials and less pigment are needed. According to KWS, this makes it a high-quality durable mixture of equivalent quality to the normal red Stone Mastic Asphalt (SMA) and has the same lifespan. With the production of standard red SMA, the emission is 156 kg CO2 per tonne, while with recycled red SMA this is reduced to 92.7 kg with 40 percent recycled asphalt. This also reduces the Environmental Cost Indicator by 41 percent.
KWS has ‘horizontally’ recycled the old top layer of the red asphalt. This means that it was milled on site and 40 percent was reused in the new top layer of the same road. This percentage is very high for a red top layer, because according to the legal, technical and administrative conditions in civil engineering recycled asphalt may not be used in SMA. The municipality of Eindhoven dropped this requirement, giving the innovative material a chance.
In addition to the red lanes, a black lane was realized in the middle of the road. This track was also milled and replaced by an SMA mixture developed by KWS with 50 percent recycled asphalt. The production of standard black SMA emits 76.2 kg of CO2 per tonne, while with recycled black SMA this is reduced to 58.8 kg with 50 percent recycled asphalt, reducing the Environmental Cost Indicator value by 27 percent extra.
