Effects of Temperature Curling on Airfield Rigid Pavement Responses

ABSTRACT Pavement response measurements were collected from an in-service concrete pavement at the Denver International Airport. The effect of temperature curling on the measured strain and deflection responses for a several aircraft and load locations was analyzed. Theoretical slab analyses were also performed to compare the combined temperature and load stresses with the stress range, calculated as the difference between the combined and temperature-only stresses. The theoretical stress analyses showed that combined stresses (total) due to load and temperature were significantly different than stress range. The total stresses were greatly affected by the temperature difference magnitude and the assumed temperature distribution type (linear or nonlinear), whereas stress range was not as sensitive to changes in the slab's temperature differential or temperature distribution type. The measured deflections, caused by moving aircraft gear loads, were affected by temperature differential at the transverse dummy joint and corner location for dual and dual tandem aircraft. Overall, the measured deflections at the interior and hinged longitudinal joint were not as sensitive to the slab's temperature differential. Aircraft gear weight was the most significant factor in the measured deflection magnitude, whereas the aircraft individual wheel load was most related to the measured tensile strain magnitude. The measured strain was more sensitive to temperature differential for dual wheel aircraft loading, while the strain-induced by the dual tandem aircraft was not very sensitive to the slab's temperature differential. The slab positions, where significant gaps existed between the slab and base, also showed a relationship between the measured responses and temperature differential. The theoretical analysis and measured field data suggested temperature curling can be directly and accurately accounted for in airfield rigid pavement design only if the key stress components leading to slab fatigue cracking (total stress, stress range or both) are determined from full-scale experimental testing.