Commercial building flooring failure caused by swelling of the foundation layers

The work describes the damage, testing and method of repairing the flooring. The flooring formed part of a commercial pavilion covering an area of approx. 1200 m2. Significant damage in the form of cracks and elevations of up to a height of almost 80 mm were detected in the flooring. Geodetic, laboratory and geotechnical tests were carried out to determine the causes of the damage. The cause was found to be swelling of the floor base course layers, consisting of embankments made of unburnt colliery shale mixed with ashes. The swelling processes ceased about 5 years after the structure was commissioned.