The following are a list of current applied research needs related to concrete pavement airfields. This is only a partial list and is subject to change through discussion with the ACPTP program coordination group and/or technical advisory committee.
Mitigation Procedures for ASR Expansion in Concrete
Under the previous Airport Pavement Technology Program (APTP) between 2002 and 2006, much research was accomplished. Early alkali-silica reaction (ASR) research had suggested that airfield pavement deicer exacerbates ASR expansion in concrete. However, an APTP-funded Innovative Pavement Research Foundation report (IPRF 05-7) concluded that pavement deicer does not cause ASR in airfield pavements. Further APTP research demonstrated Class F Fly Ash, which is a waste product recycled from coal combustion power plants, to be an effective mitigator of ASR expansion. However, with the slowdown of coal-fired power plants resulting in limited supplies of Class F Fly Ash, other means of mitigating ASR expansion must be found. Research is needed to find alternative materials and methods for mitigating ASR expansion in concrete pavements as well as to develop a new rapid test procedure to identify ASR-susceptible aggregates.
Best Practices for Rapid Repair and Rehabilitation of Airport Pavements
In 2002, a guide was developed on Accelerated Airfield Concrete Pavement Rehabilitation and Reconstruction that covered the planning, design, and execution of airfield rehabilitation and reconstruction projects. This guide was based on materials and processes that were available up until that point in time. However, new developments in construction materials and processes, such as stringless technology and specialty cements, exist today that were not available then. In today’s environment, it is even more apparent that closing airfields, even in part, can have detrimental impacts on airport operations and therefore that such closure must be minimized. As a result, research is needed to develop best practices for rapid rehabilitation using current technologies.
Mixture Proportioning for Airfield Pavements
Research is ongoing with performance-engineered mixtures for highway pavements. However, the differences between highway and airfield pavements are significant, including different mixture performance requirements. These mixture-related differences need to be evaluated, understood, and cataloged. Procedures and best practices for concrete mixture optimization with airfield pavements need to be developed and incorporated into airfield specifications.