Assessment of Joints in Concrete Pavements Exposed to Different Winter Conditions

Abstract

Signs of premature deterioration are customarily observed in areas adjacent to joints in concrete pavements. These areas, especially in cold regions, continue to hold water/solution (due to application of deicing salts) long after wetting events. This solution can contribute to the deterioration process by physical or chemical mechanisms. Until now, the root causes of joint deterioration are not fully understood because a multitude of reactions and mechanisms may be responsible for this deterioration. The goal of this study is to use forensic evaluation to classify the source of this damage and identify aspects contributing to joint deterioration of regional roads (chloride-based salts are directly applied) and residential streets (salts are borne by vehicle tires) in Winnipeg, Manitoba, Canada. In addition to visual inspection, this study characterizes the quality of air-void parameters and bulk properties (e.g., absorption, penetrability) of cores collected from both regional roads and residential streets. Also, the alteration of microstructure in concrete was assessed by thermal, mineralogical, and microscopy studies. The results revealed that the cores collected from regional roads had high intensity of microcracks and most air voids (both small and large) were filled with various levels of secondary depositions compared with the cores collected from residential streets. The deterioration of concrete is explained by a combination of physical and chemical aspects, due to the interaction of salts, freezing/thawing cycles, and wetting/drying with the hydrated paste.