Evaluation of Asphalt Mixture Performance Using Cracking and Durability Tests at a Full-Scale Pavement Facility

Abstract

In the asphalt materials community, the most critical research need is centered around a paradigm shift in mixture design from the volumetric process of the previous 20-plus years to an optimization procedure based on laboratory-measured mechanical properties that should lead to an increase in long-term pavement performance. This study is focused on advancing the state of understanding with respect to the value of intermediate temperature cracking tests, which may be included in a balanced mix design. The materials included are plant-mixed, laboratory-compacted specimens reheated from the 2013 Federal Highway Administration’s (FHWA’s) Accelerated Loading Facility (ALF) study on reclaimed asphalt pavement/reclaimed asphalt shingle (RAP/RAS) materials. Six commonly discussed intermediate temperature (cracking and durability) performance testing (i.e., Asphalt Mixture Performance Tester [AMPT] Cyclic Fatigue, Cantabro, Illinois Flexibility Index Test [I-FIT], Indirect Tensile Cracking [ITC, also known as IDEAL-CT], Indirect Tensile Nflex, and Texas Overlay Test) were selected for use in this study based on input from stakeholders. Test results were analyzed to compare differences between the cracking tests. In addition, statistical analyses were conducted to assess the separation among materials (lanes) for each performance test. Cyclic fatigue and IDEAL-CT tests showed the most promising results. The ranking from these two tests’ index parameters matched closely with ALF field performance. Furthermore, both showed reasonable variability of test data and they were successful in differentiating between different materials.

Evaluating the Sensitivity of Intermediate Temperature Performance Tests to Multiple Loose Mixture Aging Conditions Using the FHWA Accelerated Loading Facility’s RAP/RAS Experiment

“…The FI has correlated reasonably well when compared with accelerated loading sections at FHWA’s ALF and NCAT ( 27 , 29 ). The same holds true for transverse-cracked sections in the Chicago, Illinois area ( 32 ).…”

“…This section will highlight indices that will be elaborated on in the discussion of results, and the testing details will be provided in the Materials and Methods section. The three cracking tests described emerged as a result of Golalipour et al ( 27 ) and technical input from stakeholders.…”

“…a T = time-temperature shift factor from dynamic modulus master curve; As it pertains to field correlations, Golalipour et al (27) and West (37) show promising results from FHWA ALF and NCAT Test Track, respectively. A limited field verification was also done in Wang et al (35) for a modified binders study at the FHWA ALF (38), where sections were constructed in 2002.…”

Finite Element Modeling of FHWA-Accelerated Loading Facility Test Sections With Fatigue Damage Using a Nonlinear Viscoelastic Cohesive Zone Integrated With Gaussian Damage Evolution

“…It should also be noted that the Lane-8 showed a vertical degradation rate, which was not expected as the laboratory test results of the mixture used in Lane-8 indicate that its performance should be better or comparable to that of Lane-6. This is a result of drainage issues being observed in the unbound layers in Lane-8, which substantially shortened the performance life of the lane ( 15 ).…”

“…FlexPAVE TM uses a 3D-FEM model of the pavement to simulate stress-strains under a moving load and then uses continuum damage models to predict the fatigue and rutting distresses (7)(8)(9)(10)(11)(12)(13). The fatigue damage analysis is based on the simplified viscoelastic continuum damage (S-VECD) model for the AC layer (14,15). The main components of the S-VECD model include a damage-characteristic curve for the AC mixture and its failure criterion which are typically obtained through laboratory tests such as direct cyclic tension tests on cylindrical specimens.…”