T. Farnsworth
Luna Innovations, Inc.,
United States
Keywords: Concrete, polymer, rapid set, runway repair, non-toxic
Summary:
Adequate airfield facilities are critical for successful U.S. military operations. Rapid recovery of flight operation is imperative when the runway has been damaged. The U.S. Air Force has invested significant resources into a rapid airfield damage recovery (RADR) sequence that restores the substructure and surface of runway craters. However, commercially available capping materials, including calcium sulfo-aluminate cements and polymer concretes, have not satisfied the performance metrics for rapid recovery. Each material has failed to meet at least one of the performance requirements due to short working lifetimes, extended cure times, premature structural failure, or temperature/environmental instability. The problems plaguing these commercially available rapid-set materials preclude their use in the Air Force repair sequence. Therefore, there is a need for an alternative repair material that can be rapidly cured while still maintaining a long working life for practical site application and prompt airfield recovery. To address this need, Luna has developed an epoxy concrete patch that features a rapid-setting technology with a long, tunable working life. Unlike the extremely short working times (< 15 minutes) of commercial rapid-setting hydraulic and polymer concretes, Luna’s innovative polymer concrete exhibits a greater than 5 hour working life with high strength being achieved in just 1 hour after patch application. The rapid-setting polymer patch technology has a 2-hour compressive strength of 58.7 MPa (8,519 psi, ASTM C39), 1-day bond strength of 9.97 MPa to PCC (1,446 psi, ASTM C882, PCC = Portland Cement Concrete), and a 2-hour modulus of elasticity of 19 GPa (2,740 ksi, ASTM C469). This technology can be used to patch cracks, holes, and larger area crater repair sites to restore the original integrity of the structure or surface. Upon curing, the repaired runway could support a C-17 landing less than one hour from the point of application. The novel polymer concrete fits into the existing repair sequence outlined by the Air Force and has demonstrated low temperature stability, water resistance, and high bond strength to typical runway PCC that outperforms commercially available repair materials. This material is based upon work supported by the AFCEC under Contract No FA8051-20-C-0012. Any opinions, findings and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the AFCEC.