SURFACING OF STEEL BRIDGE DECKS EXEMPLIFIED BY THE FAROE BRIDGES --BITUMEN, FLEXIBLE AND DURABLE. 3RD EUROBITUME SYMPOSIUM 1985, THE HAGUE, NETHERLANDS, SEPTEMBER 11-13, 1985

In 1970 the Danish road authorities intended to pave a new 28000 m2 bridge with an orthotropic steel deck. Extensive experiments with different materials and constructions were carried out to develop a surfacing with a long lifetime and a minimum of maintenance. The final decision was based on results from skidding tests, rutting tests and durability under varying load at low temperature. These tests were carried out on samples in full thickness comprising all layers of the surfacing. The following construction was chosen: 30 mm mastic asphalt, wearing course type; with chippings; 25 mm mastic asphalt, binder course type; 4 mm special asphalt mastic; 300 g/m2 rubber-resin adhesive; bridge deck sandblasted to metallic cleanness (sa 3). It was used on the before-mentioned lillebaelt bridge and in the following years on several steel deck bridges in Denmark, Norway and Sweden. A modified type was developed for use on bascule bridges. This surfacing is used without dowels or other supports. During execution of the surfacings, the workmanship and materials were controlled closely. This is considered an important reason for the results achieved. Until now, all the surfacings have acted satisfactorily. Only negligible repair has been necessary, and based on the experience so far, a total lifetime of 20-25 years is expected. The 60000 m2 faroe-bridges were surfaced in the period from autumn 1983 to spring 1985. The same surfacing with a slight modification of the adhesive has been used and the experience till now indicates, that the result will be fully satisfactory.(a) for the covering abstract of the symposium see IRRD 815173.