Field performance of cold- and hot-applied joint sealants

Abstract

Stone mastic asphalt (SMA) and thin surfacing have been used in the UK for over 15 years. The primary location of failure and deterioration on the majority of thin surfacing is along the longitudinal joints. Traditionally, contractors used hot bitumen as the joint edge sealant material. More recently, many contractors used cold-applied bituminous edge sealants. This paper presents the findings of field and laboratory investigations aimed to explore which method provides the optimum performance of longitudinal joints. Dynamic shear rheology (DSR), indirect tensile strength (ITS), pull-off, permeability and air void content tests were performed. The results of the DSR tests showed that cold-applied sealant could outperform the field performance of the hot-applied 40/60 pen bitumen sealants. However, the adhesion and ITS tests showed that hot-applied sealant was more effective than the cold-applied sealant in creating a good bond between two asphalt mats. There was no significant difference in the permeability of joints constructed using either sealant. The survey of roads constructed using hot- and cold-applied sealants showed that both methods are capable of constructing durable longitudinal joints on roads with low-to-medium traffic volume.