This paper shows how early research has indicated that the current specification for the selection of crack sealants, correlates poorly with field performance. In order to address this issue and help predict the low temperature properties of hot-poured bituminous sealants, a modified Bending Beam Rheometer (BBR) method is utilized. Eight sealants, with a wide range of rheological behaviors, were tested between -4 and -40??C. When the time-temperature superposition principle was used, the stiffness after 240s at a temperature T was equivalent to the stiffness after 5h of creep loading at a temperature of T+10??C. The results indicate that the stiffness of hot-poured sealant at 240s help predict low temperature behavior. In addition, the rate of stiffness change in a log-log scale (m-value) can be used to assess stress relaxation. Two additional parameters are thought to provide a useful indication of the sealant performance at low temperature: steady-state creep rate, obtained after a 240s loading; and the average creep rate, based on deflection measurements over the 240s.
Abstract