LAUSR

In this study, tracking (the pick-up of tack coats by construction vehicle tires during construction activities) resistance of Oregon slow-setting grade and “New” engineered emulsions were investigated. Tracking reduces the amount of tack coat in particular areas and creates a non-uniform tack coat distribution between the two construction lifts. This non-uniform tack coat distribution leads to localised distresses and even complete failure of the bond between lifts. Oregon tack coat curing times, tracking resistance, and the factors that influence them were determined and evaluated in this study. Tracking resistance was evaluated by developing a wheel tracking device that can be used in the field as a visual tool or by collecting weight data via the removable rubber “tires”. Evaporation tests were used to create a linear regression model to predict in-situ curing times and develop a smartphone app using the created model. Prediction of in-situ curing times, along with the wheel tracking device, will reduce tracking and improve current tack coat quality-control and quality-assurance procedures.