01550071

Component

In perpetual pavements, damage from bottom-up cracking can be limited to the top surface lift through using a very thick surface layer or a binder-rich intermediate layer. This can be attained by maintaining tensile strains at the bottom of the hot-mix asphalt (HMA) layer below a certain value known as the fatigue endurance limit (FEL). This paper presents a method for estimating a strain-based fatigue endurance limit for flexible airfield pavements. The proposed method is based on the concept that a 50% reduction in HMA layer modulus would indicate initiation of fatigue cracking. Falling Weight Deflectometer (FWD) testing results, collected from National Airport Pavement Test Facility (NAPTF) flexible pavement sections, were analyzed to determine at which loading pass each section had a 50% reduction in HMA layer modulus (N sub f50). NAPTF tensile strain data were also used to determine the tensile strain at N sub f50 for each pavement section by averaging the peak tensile strains. The proposed approach was validated by comparing its results to those obtained using a common FEL estimation model known as the Rate of Dissipated Energy Change (RDEC) model. To further verify the results of the proposed approach, peak tensile strain was plotted versus number of loading cycles for all sensors. Using these plots, the peak tensile strain at which the variability in the strain gage data increased was used as an estimate of a possible FEL. The N sub f50 tensile strains estimated using the proposed method were comparable to the values determined from RDEC and variability approaches.

This paper was sponsored by TRB committee AFD40 Full-Scale Accelerated Pavement Testing.

01550057

15-0900

English

17p

2015

Transportation Research Board 94th Annual Meeting

Digital/other

Figures; References; Tables

Airport runways; Falling weight deflectometers; Fatigue limit; Flexible pavements; Hot mix asphalt; Modulus of elasticity; Perpetual pavements; Tension

National Airport Pavement Test Facility

Layer moduli

Aviation; Design; Pavements; I22: Design of Pavements, Railways and Guideways

Transportation Research Board Annual Meeting 2015 Paper #15-0900

TRIS, TRB, ATRI

Dec 30 2014 12:23PM