https://www.mdu.se/

Tar asphalt containing harmful pollutants has been in our roads for a long time before its harmfulness was discovered in the 1970s. Prior to 1973 in Sweden, tar asphalt was a common repair material when repairing roads. A lot of the documentation of where repairs have been made prior to 1973 have disappeared over time. This means that if a road that existed before 1973 is to be rebuilt, the road must be environmentally invented for the presence of tar asphalt. The purpose of this degree project is to examine the methods that the consultant company ÅF uses today to identify tar asphalt in projects. To identify these methods a literature study has been made, analysis of past projects of ÅF and interviews with personnel of the company. An important problem that was identified is related to the field tests that are quite uncertain and can only identify quite high levels of pollutants in the asphalt. Further improvements for how to solve it would be implementing lab analysis of all samples on road projects where the margin for error is smaller. For all smaller or medium sized projects, a more cost-efficient method using mainly field tests as they use today appear the best solution.