Load induced microcracking and its effects on the air permeability of mortar

grantor: University of TorontoVery little work has been reported on directly relating mechanical response with durability response. The objective of this thesis was to fill this gap by correlating the change in permeability with an increasing uniaxial load on mortar cylinders. To facilitate this, a uniaxial compression test was conducted simultaneously with an air permeability test. An apparatus was designed which would allow for such a test. The main components of the apparatus involved two specially designed permeability platens, strain gauges, RTV (room temperature vulcanised rubber) Pena-Seal (an epoxy) and an outer PVC shell. It was concluded that permeability remains unaffected until a threshold level is reached, after which the permeability increases until failure. Additionally, since these threshold levels are so high, load induced microcracking will not affect actual concrete structures. It was recommended that microcracking caused by other processes such as shrinkage and corrosion be studied for their effects on permeability.M.A.Sc