VTT started a 5-year asphalt pavement research project ASTO in 1987 where the prime goal was to decrease the pavement rutting 30% from the existing level (wear + deformation together) by using an empiric-arithmetic research system. The whole project has been divided into 10 research areas which are binder, aggregate, additive, mix, AC-pavements, OG-pavements, mixing, spreading and compaction, maintenance, and rehabilitation. At the beginning, the preliminary studies and the workplans were made (year 1987, all together 23 sub-projects). The mix-studies (9 pieces) will be brought to an end in 1990. Thework method studies, mixing, spreading and compaction (10 pieces), will be entered on the reports in 1990 at the latest. A large test road network will be constructed in 1990-91. The other method studies, maintenance and rehabilitation, are going to start in 1990 (16 sub-projects). The final results and the whole planning system with its models will be completed in 1993.
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