Life-cycle maintenance management of traffic tunnels - strategy assessment to develop new calcification reduction methods in tunnel drainage system

The formation of lime deposits by seepage or ground water in tunnel drainages occur mainly because of the calcium carbonate in the water. Alkali compounds contribute considerably to the formation of lime deposits by the elution of calcium compounds and by raising the pH-value. Water hardness stabilization using polyaspartic acid has a positive influence on the lime deposits. Fewer and less harder deposits are formed. This renders it possible to lengthen the intervals between cleanings and the costs for the cleaning of the pipes can be reduced. The output per shift increases and the maintenance costs are reduced. The accompanying sequential inspection strategy leads to a significant reduction of the cleaning costs. As a consequence there is less strain on the pipes and the durability of drainage systems increases.