Permeability of cracked concrete

The goal of the research presented here was to study the relationship betwe en cracking and water permeability. A feedback-controlled test was used to generate width-controlled cracks. Water permeability was evaluated by a low -pressure water permeability test. The factors chosen for the experimental design were material type (paste, mortar, normal and high strength concrete ), thickness of the sample and average width Of the induced cracks (ranging from 50 to 350 micrometers). The water permeability test results indicated that the relationships between permeability and material type differ for u ncracked and cracked material, and that there was little thickness effect. Permeability of uncracked material decreased from paste, mortar, normal str ength concrete (NSC) to high strength concrete (HSC). Water permeability of cracked material significantly increased with increasing crack width. For cracks above 100 microns, NSC showed the highest permeability coefficient, where as mortar showed the lowest one.