Characterizing the Low-Temperature Performance of Hot-Pour Bituminous Sealants Using Glass Transition Temperature and Dynamic Stiffness Modulus

Joint and crack sealants exposed to cold climates experience high tensile stresses. Sealants should have the ability to dissipate these stresses to perform their function properly. In cold climates, the state of sealing materials may change from rubbery to solid state due to low in-service temperatures. As a result, sealants become stiffer and less capable of dissipating the induced tensile stresses. This paper introduces a laboratory characterization method for joint sealants based on dynamic testing at low-temperatures. The dynamic mechanical analyzer test was conducted on seven hot-pour bituminous sealants in the temperature-sweep mode to characterize the stiffness-temperature behavior of sealants. Glass transition temperature, which is the boundary temperature between rubbery and solid states, was estimated for each sealant. Glass transition temperature and low-temperature stiffness can be used to predict the field performance of sealants, and to evaluate the compatibility of a sealant to a certain environment.