Deterioration of concrete joints under low-intensity, high-cycle loading

This paper reports on the results from a series of laboratory tests assessing the rate of deterioration for concrete cracks and joints under low-intensity, high-cycle loading, typical of that found in industrial flooring, external hardstandings and rigid pavements. The testing incorporated a variety of crack geometries, reinforcement types, reinforcement quantities and load magnitudes for over 80 half-scale prism specimens. The data presented demonstrates that joint/crack failure contains four distinct phases of deterioration, each controlled by a different mechanism of material degradation. ‘V'-shaped cracks were found to produce a higher load transfer than the equivalent surface width parallel crack, with the incorporation of A142 fabric and steel fibres significantly reducing differential displacement and crack face deterioration. The data has enabled serviceability limits to be established for each of the material parameters tested, keeping differential displacement within acceptable levels and preventing the onset of failure.