Lektion 5 Test

Some of the weakest roads will need load restrictions every year but most roads will only have problems during the most severe winter freeze-thaw cycle periods, or during spring thaw weakening periods.

The standard tyre pressure of a truck is 800 KPa and is designed for trucks traveling fully loaded at 100 km/h.

Mode 1 rutting.

This structure can be expensive and inefficient and can cause settlements. The reason of the underlying problems should always be investigated first and, based on the findings, the best solution selected.

Mixmilling does not help with frost heave problems.

In mixmilling the road structure is homogenized and crossfalls can be improved. The improvement of grain size distribution is normally so low that it does not improve resistance against Mode 1 rutting – especially if the pavement is thin.

Foamed glass is usually used as insulation material.

This structure can temporarily fix spring thaw problems, but if the road is already suffering from spring thaw weakening problems, a new wearing course and drainage improvement will not help. A good solution is the removal of the old wearing course, followed by a new base course 20-30cm, a new wearing course and a drainage improvement.

It is difficult to add new layers to a road in a cuttings due to the lack of space beside the road and because vertical geometry of the road will be worse (that is why road cut was originally designed). Soil replacement is a more suitable solution.