Use of aggregates from regional deposits in road construction

For highway construction and maintenance, between 200 and 300 million tons of mineral aggregates are used in the Federal Republic of Germany per year. Most of the regionally occurring rocks, gravels and sands are sources of road materials of very good quality. However, depending on the locale, aggregates of minor quality may also have to be used for highway construction and maintenance for economic reasons and in order to protect the environment by avoiding greater haulage distances. For this purpose it has been necessary to adapt aggregate treatment and pavement design techniques to the rock materials available in each case. A number of different tentative approaches to solving this problem have been put forward.