An Integrated Approach to Identify ASR Distress in Airfield Concrete Pavements

摘要

To date, alkali-silica reactivity (ASR) has been identified in a number of highway concrete structures. However, there is very limited data on the occurrence of ASR in airfield pavements, such as runways, taxiways, and aprons, although damage to concrete due to ASR can jeopardize the safety and functionality of the airfield pavement. A study was undertaken to develop a protocol for ASR distress rating analysis in airfields. It includes both field evaluation and laboratory investigation. Two candidate US airports with known pavement cracking were selected for this purpose. The effectiveness of field detection kits was assessed. One of the primary tasks was to distinguish distress due to ASR from other forms of distress. Complimentary to this, the contribution of ASR towards total damage was assessed. Field inspection was followed by collection of cores from strategic locations for laboratory investigation, which included microstructural identification of ASR gel, and reactive aggregates, characterization of distress features, and estimation of damage. Finally, a distress rating scheme was developed for airfield pavements. The study reiterates the importance of proper inspection, followed by detailed laboratory investigation to assess ASR-related damage to airfield pavements.