Frost action is an aggravating and costly problem in regions where highways are exposed to sub-zero temperatures for prolonged periods. Pavement distortion can create hazards for the driving public and contributes to the deterioration of the overall pavement structure. Special highway design and construction features are often required to deal with this problem. Such treatments have included drainage improvements to the pavement structure and excavation of frost-susceptible material. Because of the excessive frost penetration in northern ontario, however, such treatments are not always practical. In 1966, the ontario ministry of transportation and communications beganusing expanded polystyrene to insulate the subgrade at frost heave sites. Traced in this paper is the work carried out by the ministry to evaluate the effectiveness of polystyrene. The establishment of specifications and standards currently in use to control frost heaving are also discussed. Reference is made to the ministry's site-selection criteria on minimizing the potential for pavement icing over insulated sections. The ministry also uses expanded polystyrene to insulate sewer and water mains and to prevent differential heaving at critical installations such as truck weigh scales. Standard drawings are included that illustrate the installation details. The paper concludes by describing several special projects on which relatively large quantities of polystyrene were used to control frost heaving. This paper appeared in transportation research record no. 1146, Frost protection and insulation for transportation facilities. For covering abstract see IRRD no 817763.
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