LAUSR

Hot liquid-applied rubberized-asphalt membranes (referred to in this paper as HRA membranes) have over a 40-year track record of use in roofing and waterproofing applications. In the authors' experience, this use has been generally consistent with respect to surface preparation and membrane application procedures. However, the physical and material properties of HRA membranes are not well known and not consistently reported by all manufacturers, leaving designers with limited basis for comparing products. Further, the industry has not reached a consensus on defining adequate adhesion of HRA membranes in the field, or standard field testing procedures for quantifying membrane adhesion. The testing procedures and minimum performance requirements historically used for evaluating HRA membranes are found in a Canadian General Standards Board (CGSB) standard withdrawn in January 2005. However, this archaic standard is still considered the only material standard for HRA membranes in the industry. ASTM International committees are currently developing new standards for the testing and application of HRA membranes based on CGSB Standards recognized in the industry, but consensus has not yet been reached. The laboratory testing program summarized in this paper was performed in two phases, and with five commonly used HRA membrane products. The authors designed the Phase 1 program to compare physical properties of HRA membranes to better understand membrane durability and expected performance across the different products. Phase 1 testing also included material analysis of each HRA membrane, focusing on percentages and types of fillers used with the rubberized-asphalt products. Phase 2 was primarily an adhesion testing program developed to evaluate the bond of HRA membranes to concrete with various surface profiles and preparations, but also included low-temperature flexibility membrane testing and tensile strength testing of reinforcing fabrics used in fabric-reinforced HRA membrane assemblies.