State-of-the-Practice: Rubblization of Heavy Load Concrete Airfield Pavements

Within the FAA Integrated Airport System airfield infrastructure and the U.S. Defense Department airfield inventory, there are more than 83 million square meters (100 million square yards) of heavy load concrete airfield pavements greater than 33 cm (13 inches) in thickness and more than 35 years old. These pavements will need major rehabilitation within the next 10 years. Traditionally, concrete pavement restoration (CPR) procedures (including techniques such as sub-sealing, full-depth patching, partial-depth patching, load transfer reconstruction, diamond grinding, and joint sealing) have been employed to maintain these pavements in a fair to good condition. These CPR procedures are becoming less effective today as the present pavement condition ratings are reaching a critical point where major rehabilitation is required. Rubblizing concrete pavement is becoming the paramount concrete pavement rehabilitating technique adopted by state highway agencies for heavy load highway pavements (Armaghani, 1999). From 1994 – 2002, states in the northeast, south and Midwest United States have rubblized Portland Cement Concrete Pavement (PCCP) and placed Hot Mix Asphalt (HMA, primarily Superpave) overlay over more than 41 million square meters (50 million square yards) of highways. Most experience with the proven rubblization technique has been with concrete pavements of thickness between 20–30cm (8–12 inches). However, new concepts have been employed to successfully rubblize up to 66cm (26 inches) of heavy load concrete airfield pavement at two military airfields. Information acquired during construction of these projects provided criteria for development of prototype Rubblization equipment for heavy load concrete airfield pavement in the 66cm (26 inches) range. This paper presents the concepts associated with the process of Rubblization, equipment development, in-service performance and specification criteria for rubblizing heavy load concrete pavements. Discussion is placed on rubblization process; characteristics of state-of-the-practice equipment; project performance at Wright-Patterson Air Force Base, OH, and Selfridge Air National Guard Base, MI; and specifications for rubblizing heavy load concrete pavement.