An Investigation into Deicer-Induced ASR Distress in Concrete

Abstract

Recent investigations into premature deterioration of concrete pavements in some airfields in the United States have suggested the possible role of deicing and anti-icing chemicals in inducing alkali-silica reaction (ASR) in concrete. As a result, a comprehensive research study was undertaken to investigate the role of deicing solutions in causing ASR in mortar and concrete test specimens. This paper presents the findings from the research study conducted to evaluate the influence of potassium acetate deicer/anti-icer in causing alkali-silica reaction (ASR) distress in concrete specimens. A test procedure based on modifications to the standard ASTM C 1293 test method was employed in this investigation, wherein the concrete prisms were exposed to deicer solutions during the course of testing. In addition, standard ASTM C 1293 tests were conducted on the same aggregate sources to establish a reference. Expansion of the test specimens was monitored periodically, along with changes in their dynamic modulus of elasticity. pH of the deicer soak solution was also monitored. Visual and scanning electron microscopic (SEM) examinations were conducted at the conclusion of the tests. Findings from this study indicate that potassium acetate deicer solutions caused aggressive ASR in concrete specimens containing reactive aggregates. In addition, a secondary reaction product, primarily composed of a potassium sulfate phase, was observed in prisms containing both reactive and non-reactive aggregates. Additional research is identified to decipher the precise mechanisms involved in this attack.