Processes that Control the Development of Salt Quantity on Road Surfaces after Salt Application

摘要

This paper is part of a project to study how the quantity of salt on road surfaces developsafter salt application. The goal of the work presented in this paper was to identify the physicalprocesses that control the development of salt quantities on road surfaces. Field observationshave been made to study the salt quantity after application. Based on the results from fieldobservations, the authors suggest that the development of salt quantity after salt application iscontrolled by three processes; the initial loss, the dissolution of salt and the loss of salt. Atheoretical approach to investigating the process of salt dissolution is made. A principal, physicalbased model for the measured salt quantity on road surfaces as a function of traffic is presented.The dissolution of salt is proposed to be expressed by an exponential equation and the rate ofdissolution is mainly dependent on the water quantity on the road. The loss of salt caused byblow-off and spray-off is considered to follow an exponential curve. The resulting equationincorporating both the dissolution and loss is finally compared with field observation for moistand wet road surfaces.