Properties of Weathered Uncoated and 'Resaturant'-Coated Bituminous Built-Up Roofing Membranes.

摘要

A study to compare the performance properties of weathered built-up membranes which had and had not been subjected to an application of resaturant'-type coatings has been conducted. The membrane samples (asphaltic and coal-tar pitch), which were taken from roofs of buildings, ranged in age from 14 to 26 years. Sections of these roofs had been treated with one of three proprietary resaturant'-type coatings. The age of coatings ranged from 12 to 29 months. The membrane samples removed from the roofs were visually examined in the laboratory to determine their general condition, the extent of adhesion between plies of felts, the number of plies, and the thicknesses of the interply bitumen. The visual examination indicated that damage to some areas of the top ply of felt of most of the coated coal-tar pitch membrane samples had occurred. The damage was attributed, in part, to removal of the aggregate surfacing prior to 'resaturant'-coating application. Membrane properties measured in the laboratory for undamaged test specimens were tensile strength, load-strain modulus, flexural strength, maximum deflection (flexure), coefficient of linear thermal expansion, and thermal shock factor.