Don't be mislead by the picture, we are indeed aware, that in this case, two waterways are crossing each other. This can clearly be seen by the fact that the slipways, generally found on motorways, are missing. This picture by the way, was taken in the area around Magdeburg in the north-east of Germany and is part of the project 'German Unification'. We simply couldn't resist using it to make the page about road construction innovations a little more attractive.

The ideas that the road-builders have are really astonishing. The fact that they have to urgently provide a quieter road surface, because the noise from the tyres, even from a great distance indicates, without a doubt, that there is, e.g., a motorway in the vicinity, is a well known fact. That problems do occur and that an only recently laid surface must be replaced, is also well known.

Roads or bridges with underfloor heating are probably still quite new. In this case, a federal-road bridge over the Elbe-Lübeck-canal, which cost almost €10 million, is being equipped with heating, at a cost of a further €1 million. The heat is brought up from a depth of 100 meters and radiated under the mastic asphalt surface by means of a Glycol-mixture. Thus avoiding dangerous icing conditions when the temperatures drop to around freezing point.

That however, is not enough for the road-builders. They also want to combat the heat in the summer months, which at more than 50°C, makes the asphalt so soft that it is already, e.g., through heavy loads, being damaged. Therefore, they cool the surfaces with their heating circuit pumps, thus enabling a greater road-surface durability.

Also the reasons for the multitude of road-works and the resultant tail-backs, give food for thought. A new repair-system should help. The damaged stretch of road will be precisely surveyed and then cut out, so that a concrete block which has been brought along, will fit precisely into the gap. The height adjustment follows through dowels inserted into the road-works and the sealing is done with silicate resin. It's all over in less than two hours after the closing of the road. If done at night, it should cause hardly any problems.

Now, these were only two examples of the realisation of greater plans for the 'Roads in the 21st century'. They should not only help to save time but integrate well into the landscape and assist with the sparing use of resources. They should also standardise road building and be repairable, perhaps even provide energy. They should also be able to report, so to speak, on their own respective conditions. Not really directly from the road surface, but more from the cars driving on it.

Nevertheless, the installation of sensors is also still being planned, this will enable a better analysis of pending damage, particularly on bridges. If then the chemical compounds in the road surface can combat the remaining air-pollutants and if the multiple possibilities of traffic influencing systems and noise barriers are used, then we'll soon have more technology in the surrounding environment than in the cars themselves.

One final example may make it clear, even though the actual technology is not visible. Engineers in The Netherlands have apparently succeeded in placing bacteria in the cracks in the concrete, when rain water gets into these cracks, these bacteria produce a substance which closes, thus sealing the crack. Up to now however, the process is only effective in cracks having a width of less than 1 millimeter.

In customary road construction, the draining off of water as a protection against frost damage, is done by laying a foundation of coarse gravel (basalt). A small gap results between the ice and the more fine-grained minerals, this gap is so small and because it's walls are so smooth, a capillary effect is possible. Were this effect not interrupted by the gravel, more and more water could be soaked in directly underneath the asphalt surface.

The idea of repairing the asphalt purely by introducing inductive heat, comes from the Netherlands. Indeed, this cannot be be done with customary asphalt, a certain amount of steel-wool is mixed into the asphalt and the temperature is held at exactly 85°C. If the temperature is too low, the asphalt doesn't melt, if it's too high, the asphalt burns. Thus, it may be necessary, e.g., every two years, to heat the entire road surface to prevent water seeping in and thus, double the service life. 07/13