Reflection Cracking on PAF Asghar Khan Airfield Pavement-Investigation, Mitigation and Rehabilitation

Abstract

One of the major distress observed in runways and airfields are cracks which appear on their surface with the passage of time owing to various reasons. There is a high chance that these cracks have appeared directly above the cracks or the joints in the asphalt or PCC layer beneath. These cracks are classified as Reflection cracks whichlet water infiltrate to the underlying layers and causefurther moisture damage as well as weakening of the unbound layers. Engineers have been practicing different methodsto minimize, delay, and prevent reflection cracking. The PAF Asghar KhanBasemain runwaycomprises ofPCC slabs laid almost 70 years ago and rehabilitated after 20 years by overlaying the pavement with an asphalt layer. After a period of time,rectangular cracks started to form on the surface of the pavement with a pattern i.e. directly above the slab joints.The aim of this project is to analyze the type of cracks and suggest suitable remedy which may include minor, major rehabilitation or even altogether going for new construction. 1