SPWS CONCRETE SLAB-FOUNDATION SYSTEM - HISTORY

H. M. Westergaard (1926) created the basis for the mathematical calculations currently still used for concrete slabs dimensioning, after improved by Bradbury (1938) and Pickett (1946), among others.













(Load transfer bars)

Soil stabilization has been always the main problem in road construction throughout the ages.

Asphalt roads tend to follow soil settlement or swelling.

Concrete roads tend to break upon soil distortions.

Developments in geotechnical engineering and in geotechny, especially in the improvement of foundation soils, have benefited the techniques of road construction. But in many cases it is economically impossible to ensure soil stabilization.

In such cases, asphalt is not an option.

Many techniques have been used to ensure pavement's continuity, such as load transfer bars and reinforced concrete. However none of them proved to be a durable and maintenance-free solution.

Reinforced concrete cracks, steel reinforcements corrode and the concrete surface delaminates.

Load transfer bars are almost impossible to align, and do not allow any vertical movement between slabs. Any soil distortion will break the slab's joint. Such technology is not watertight, therefore infiltrations will eventually erode the base and pumping problems will emerge.

Since the early 1980s, IS.COM's technicians have been working on a solution to these problems:

1 - The joint's vertical mobility has to be ensured while maintaining the load transfer ability.

2 – The base movements have to be predicted, controlled and limited.

3 – The friction between the slab and the base has to be reduced.

4 – The joint must open without mechanical intervention but with precision and sawed while the concrete is still fresh.

5 – The joint has to be watertight.

6 - The slabs must allow horizontal and vertical movements

After many studies and tests, IS.COM has patented the new SPWS CONCRETE SLAB-FOUNDATION SYSTEM technology, THE ULTIMATE SOLUTION to all concrete pavements problems.

The SPWS CONCRETE SLAB FOUNDATION SYSTEM has solve all problems related with the instability of natural grounds , as well those related with the slab cracking due to concrete retraction or soil settlement and swelling
.