On safe ground

We market systems for compaction quality assurance.

Whatever one intends to build on the ground, it is crucial to create a stable and smooth foundation bed. This means that it is not only what you see on the surface that is important, but what lies underneath. An even surface and a foundation bed that will guarantee well-balanced support is of utmost necessity. Roads meant to carry heavy traffic must be designed to prevent the formation of wheel tracks as well as overall subsiding. Foundations for heavy structures such as tall buildings or dams etc. have other requirements.

Rolling and compacting the subsurface load-bearing strata is also critical. On the one hand, the bed must be compacted to withstand a certain amount of load, on the other, it must be smooth and even across its entirety.

Foundation stability. We make use of a relative compaction value, CMV, which is proportional to load-bearing capacity. By using spot tests, this value can be translated into an absolute measure of stability. Overall surface smoothness. By continually measuring compaction during rolling, the driver is able to watch how compacting work is going via his instruments — and decide whether or not additional passes are necessary. Compaction is also recorded in order to subsequently check that the required values have been reached. When this is carried out layer after layer, then one can be sure that the bed will hold.

The contractor can turn over a quality-assured project to his customer. Our cost-effective system pays off fast. The investment is, in most cases, recovered in a few months. Furthermore, there is little risk of subsequent compensation claims.

How the system works

Our systems are all primarily similar in design. A vibration sensor is mounted near the roller’s drum shaft. The signals are fed to a converter that analyses and converts them into CMV figures. These values are then both recorded and displayed on a screen in front of the driver.

In order to be able to keep track of where the roller has compacted longitudinally, the roller is equipped with a road meter that divides up the area into roller widths. Some instruments can be provided with GPS functions, which makes determining starting and stopping points even easier or where compacting has taken place, etc.

The collected data can be analysed using our CDSView computer program and also recorded for documentation and follow-up. Click on the illustrations to see a diagram in larger scale. The compacted area seen from above. The diagram shows 10 compaction runs. The red area is below the chosen CMV figure. Vertical section through a roller run. The red area represents a average value.  

The CMV figures can be translated, using various methods, into an absolute measuring value, to load-bearing capacity, or to density, or as an e-module.