MAINTENANCE AND REHABILITATION OF PAVEMENT STRUCTURES OF NATIONALROADS IN CROATIA Mate Sroen Professor of Civil Engineering, Transportation Department-Civil Engineering Institute of Croatia /IGH/ Croatian Academy of Engineering /HATZ/ Croatia

This paper presents main elements of the Maintenance and Rehabilitation Program, which includes more than 400 kilometers of national roads' sections. The national roads rehabilitation program, called Betterment, is financed by the Croatian Government, a loan given by the European Bank for Reconstruction and Development /EBRD/, and European Investment Bank /EIB/. The program proved to be an excellent intermediate phase of earlier planned program of construction of motorways and expressways in Croatia.The project is specific due to the problem of pavement structure bearing capacity, where the impact of freezing is considerable, as well as the problem of generally under-dimensioned pavement structure of national roads. Prior to the implementation of the rehabilitation program for these roads,the in-situ measurements and visual survey of pavement structure had taken place.The goal of this project was to rehabilitate the national roads' sections by applying simple but efficient techniques such as follows: repairing cracks; replacing cracked sections of pavement surfacing; strengthening pavement structures by thinner asphalt courses.Particular attention was given to several major rehabilitation aspects, namely the following: /1/knowledge of technical data on national roads' sections, /2/ achievement of road improvement goals,/3/ financial aspects, /4/ application of rehabilitation techniques, /5/ adequate designing.