Swedish Concrete Block Pavements Investigation of State and Performance

Concrete block pavements have a good load carrying capacity and load distribution ability. The concrete block pavement is durable, insensitive to settlements, easy to repair, bright, and aesthetically attractive. It has therefore frequently been used in urban environments. In Sweden, however, concrete block pavements have been less frequent than in other comparable European countries. There are, however, signs indicating an increased amount of concrete block pavements among new Swedish roads. Swedish as well as international experience show that modern concrete pavements perform satisfactorily. The analytical base for design is, however, limited. Consequently, improved design methods based on increased knowledge of the structural behaviour of concrete block pavements constructed according to current practice are important. The failure criteria need also to be improved. A major investigation on more than 30 concrete block pavements in different parts of Sweden have been carried mit. The investigation was focused on determination of pavement systems and pavement performance including cracking or other damages, if any. In case of damages, the damaging causes were determined. The roads investigated included buss roads, bus stops, roads for through traffic, roads in housing areas, and squares and market places. Most pavements were constructed around 1990. The overall performance was good. Problems identified were insufficient drainage on tight bases (lean concrete or asphalt), local settlements, loss ofjoint sand due to vacuum cleaning, and manhole and gully surrounds. The major investigation is followed by more thorough studies of a couple of sites. These are separated into two categories, special surveys and demo projects. Special surveys are carried out for when a more detailed investigation has to be done to determine the cause for a damage. One special survey has been carried out, Slottsskogsgatan in Goteborg. Two demo projects are planned, one of these has started, Marklandsgatan also in Goteborg. Materials, layers, and layer thickness' in the pavement system have been surveyed carefully. The pavement surface will be measured regularly in order to determine changes due to traffic loading, wear, and settlements.