Abstract
Visco-elastic behavior of an asphalt for use in constructing built-up roof membranes was investigated. Shearing strains are induced in a bonding asphalt in built-up membranes by joint movement in the substrate. Shearing properties of an asphalt was examined by the shearing tests at very slow strain rates under probable temperature conditions. The observed behavior was analysed applying Maxwell model, three elements model, four elements model, and power rule. The properties of elements in the visco-elastic models and the material constants in the power rule were expressed as functions of temperature. Then the shearing stress-strain curves were calculated based on these manners and compared with the observed curves. The power rule seems to be the most convenient method to express visco-elasticity, for the purpose of stress-strain analysis of built-up membranes, because of the simplicity of the equation.
