EFFECTS OF NEW AND CONVENTIONAL DEICING CHEMICALS ON AIRFIELD ASPHALT CONCRETE PAVEMENT

Use of deicing chemicals is an integral component of winter maintenance activities for ice and snow control on highways and airfields in the cold regions. Urea is the traditional deicing chemical used at Canadian airports. In response to environmental concerns related to the use of urea on Canadian airfield and salts on roads, alternative deicing chemicals such as potassium acetate, sodium formate and sodium acetate were fabricated and marketed. In 1992, Transport Canada initiated a series of investigations, the objective was to study and evaluate the potential deleterious effect of these deicers on pavement construction aggregates and hot mix asphalt concrete. The investigations, carried out at Carleton University, consisted of three phases, where Phase 1 examined aggregate samples subjected to freeze-thaw cycles; Phase 2 examined aged asphalt concrete samples subjected to freeze-thaw cycles; and Phase 3 examined fresh asphalt concrete samples subjected to wet-dry cycles at high temperature after a number of freeze-thaw cycles. This paper presents a summary of the investigation and provides an overview of the findings. In all phases, the samples were immersed in solutions of potassium acetate, sodium acetate, sodium formate, and urea in addition to control samples immersed in distilled water. Test results showed that asphalt cores exposed to large number of freeze-thaw cycles while immersed in a deicing solution would suffer a loss of strength and elasticity. Exposure to urea at such extreme conditions of freeze-thaw might cause a disintegration of the asphalt concrete mix. However, it is observed that when the mix was exposed to a relatively moderate number of freeze-thaw cycles, it would not suffer additional loss of strength or elasticity due to the succeeding wet-dry cycles during the warm seasons. With the exception of pavements exposed to sodium acetate, the strength and elasticity after warm wet-dry cycles were slightly higher than that before exposure to the wet-dry cycles. For the covering abstract see ITRD E118503.

Language

  • English

Media Info

  • Features: References;
  • Pagination: p. 443-52
  • Serial:
    • Volume: 1

Subject/Index Terms

Filing Info

  • Accession Number: 00963813
  • Record Type: Publication
  • Source Agency: Transport Research Laboratory
  • ISBN: 90-5809-398-0
  • Files: ITRD
  • Created Date: Oct 3 2003 12:00AM