Examensarbete

Dewatering of bridges is a central part in accident prevention. If the dewatering is working accurately it reduces the chance for aquaplaning and slippery roadsurface. Most of the bridges are dewatered by gully, sub-surfacing drain and drainage channels. During the last years a big problem with leaking sub-surfacing drain has been discovered. The damages when sub-surfacing drain leaks affects especially the surrounding concrete and the reinforcement. The sub-surfacing drain is made of plastic and is produced in three different parts, such as funnel, pipe and grating. The Swedish National Road Administration has developed a new method where the pipe and the sub-surfacing drain are manufactured in acid-resistant stainless steel. This method shall better resist heat and compressive force than the plastic method. The aim of this report was to investigate if the new method with stainless steel compared to the plastic method reduces the problems with the leaking sub-surfacing drain. We have also investigated if the problem with the present sub-surfacing depends on the plastic material, demouldning or incorrect assembly. Most of the report is based on interviews with people in the building sector. Different tests have also been made to compare the plastic and steels qualities. Our conclusion of this study is that problems with sub-surfacing drain will reduce with the new subsurfacing drain made of acid-resistant stainless steel.

Dewatering of bridges is a central part in accident prevention. If the dewatering is working accurately it reduces the chance for aquaplaning and slippery roadsurface. Most of the bridges are dewatered by gully, sub-surfacing drain and drainage channels. During the last years a big problem with leaking sub-surfacing drain has been discovered. The damages when sub-surfacing drain leaks affects especially the surrounding concrete and the reinforcement. The sub-surfacing drain is made of plastic and is produced in three different parts, such as funnel, pipe and grating. The Swedish National Road Administration has developed a new method where the pipe and the sub-surfacing drain are manufactured in acid-resistant stainless steel. This method shall better resist heat and compressive force than the plastic method. The aim of this report was to investigate if the new method with stainless steel compared to the plastic method reduces the problems with the leaking sub-surfacing drain. We have also investigated if the problem with the present sub-surfacing depends on the plastic material, demouldning or incorrect assembly. Most of the report is based on interviews with people in the building sector. Different tests have also been made to compare the plastic and steels qualities. Our conclusion of this study is that problems with sub-surfacing drain will reduce with the new subsurfacing drain made of acid-resistant stainless steel.