Joint and crack sealants exposed to cold-climates experience high tensilestresses. Sealants should have the ability to dissipate these tensile 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 ofdissipating the induced tensile stresses. This paper introduces a laboratory evaluation method for joint sealants based on dynamic testing at low temperatures. Dynamic Mechanical analyzer (DMA) test was conducted on sevenhot-pour bituminous sealants using the temperature sweep mode to characterize the stiffness-temperature behavior of sealants. Glass transition temperature (Tg), 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 evaluate the compatibility of a sealant to a certain environment.
Abstract