| Abstract | Linear expansions, that occur when vacuum saturated brick samples 13 X 13 X 76 mm (1/2 X 1/2 X 3 in.) are frozen, were measured and compared with properties of the bricks from which they were taken. Included in the study were extruded and dry-press clay and shale bricks, a concrete and a sand- lime brick, a sandstone and a limestone. Most of those were either manufactured or used in Atlantic Canada and their performance records are known. Properties determined were 24-hour immersion and 5-hour boiling absorption, saturation coefficient, compressive strength, surface area and pore size distribution. Laboratory freeze-thaw cycling tests were also conducted. Four out of nine extruded bricks and two of three dry-press bricks were considered to have failed during freezing because of cracks or breaks. The failed samples from extruded bricks had relatively high porosity, high saturation coefficients and a large percentage of pores in the 0.1 to 1.0 mu range. Three of the four did not meet the saturation coefficient requirement in CSA Specification A82.1, but passed waiver clause requirements, and three of the four are known to have failed in field service. The " failed" dry-press brick samples came from bricks with good saturation coefficients and pore size distributions and low surface area values. Their failure may relate to the method of freezing. Variations in linear change values and freezing patterns of the other bricks provide interesting comparisons with their various properties. |
|---|
