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

Author(s):  
Amir Golalipour ◽  
Varun Veginati ◽  
David J. Mensching

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.

2005 ◽  
Vol 32 (5) ◽  
pp. 789-795 ◽  
Author(s):  
Jessica Manness ◽  
Jay Doering

Field performance testing of hydraulic turbines is undertaken to define the head-power-discharge relationship that identifies the peak operating point of the turbine. This relationship is essential for the efficient operation of a hydraulic turbine. Unfortunately, in some cases it is not feasible to field test turbines because of time, budgetary, or other constraints. Gordon (2001) proposed a method of predicting and (or) simulating the performance curve for several types of turbines. However, a limited data set was available for the development of his model for certain types of turbines. Moreover, his model did not include a precise method of developing performance curves for rerunnered turbines. Manitoba Hydro operates a large network of hydroelectric turbines, which are subject to periodic field performance testing. This provided a large data set with which to refine the model proposed by Gordon (2001). Furthermore, since these data include rerunnered units, this provides an opportunity to refine the effects of rerunnering. Analysis shows that the accuracy of the refined model is within 2% of the performance test results for an "old" turbine, while for a newer turbine or a rerunnered turbine the error is within 1%. For both an old turbine and a rerunnered turbine, this indicates an accuracy improvement of 3% over the original method proposed by Gordon (2001).Key words: hydraulic turbine, efficiency, simulation modeling


2011 ◽  
Vol 255-260 ◽  
pp. 3432-3436
Author(s):  
Xian Yuan Tang ◽  
Jie Xiao

This paper systematically elaborates the impact upon performance of emulsion asphalt cold reclaimed asphalt mixture by different RAP contents, through a series of testing on six cold reclaimed asphalt mixtures with various RAP contents, such as single axle compression test, 15°C indirect tensile strength (ITS) test, 40°C rutting test and -10°C low-temperature bending beam test. Testing results indicate that 15°C ITS decreases from around 0.75 MPa to 0.58 MPa with the RAP content of mixture increasing from 0% to 100%. 40°C dynamic stabilities reduce considerably from around 19,000 time/mm of 0% RAP mixture to 3,600 time/mm of 100% RAP mixture. -10°C failure strains only change from 1500με to 2000με.


Author(s):  
David J. Mensching ◽  
Adrian Andriescu ◽  
Christopher DeCarlo ◽  
Xinjun Li ◽  
Jack S. Youtcheff

The use of re-refined engine oil bottoms (REOBs) in asphalt pavements is a topic of much debate because the aging susceptibility and quantity of the additive in the binder may affect field performance. In this study, four mixtures with varying REOB contents (up to 15%) were long-term oven aged by using a high-temperature, short-duration method (135°C, 24 h) and compared with existing data on mixtures aged with more conventional short-term and long-term oven-aging procedures. The recovered binders underwent Superpave® grading, double-edge notched tension, and extended bending beam rheometer testing, and the binders were subjected to dynamic modulus, cyclic fatigue testing in the asphalt mixture performance tester, and thermal stress restrained specimen testing. Results showed a general insensitivity when short-term oven-aged (135°C, 4 h) materials were compared with long-term oven-aged (85°C, 5 days) materials, whereas the aging process at 135°C over 24 h resulted in substantial changes to the stiffness and relaxation properties across high-, intermediate-, and low-temperature modes. The difference between the stiffness-based and slope-based low-temperature performance grades appears to be an indicator for REOB modification, with the test for physical hardening of the binder being more sensitive than standard bending beam rheometer testing. The details in this paper provide information for the asphalt pavement community to consider as specifications. Standard practices are developed to address REOB modification.


Author(s):  
Fawaz Kaseer ◽  
Amy Epps Martin ◽  
Edith Arámbula-Mercado

Long-term cracking performance of asphalt mixtures is heavily influenced by asphalt binder rheology, and changes in binder stiffness, ductility, and aging condition significantly affect the cracking resistance of the corresponding asphalt mixture. This study evaluated the effectiveness of several common and recently developed binder rheological indices in capturing the effects of binder performance grade (PG) and source, recycled binder content, recycling agent (rejuvenator) dose, and long-term aging. These binder rheological indices included the Superpave intermediate-temperature PG (PGI), the Glover-Rowe (G-R) parameter, the crossover temperature (Tδ = 45°), the rheological index (R-value), and ΔTc. This study also directly compared the binder rheological indices with the cracking performance of corresponding asphalt mixtures to explore possible correlations and their robustness. Asphalt mixture cracking performance was evaluated using the Illinois Flexibility Index Test (I-FIT) for intermediate-temperature cracking, and the disk-shaped compact tension (DCT) test and the uniaxial thermal stress and strain test (UTSST) for low-temperature cracking. Results indicated that all the binder rheological indices (except PGI) consistently captured the effects of binder blend composition and proportions and aging condition, with a few exceptions. Results also showed that the G-R parameter, the crossover temperature (Tδ = 45°), and ΔTc had the best correlation to asphalt mixture and field core cracking performance as compared with other rheological indices (PGI and R-value), with ΔTc demonstrating the overall best correlation to mixture cracking performance.


Author(s):  
Sonja Pape ◽  
Kangjin Lee ◽  
Cassie Castorena ◽  
Y. Richard Kim

The use of 38-mm-diameter small specimens for uniaxial dynamic modulus and cyclic fatigue asphalt mixture performance testing offers a significant opportunity to improve the efficiency of laboratory-fabricated specimen testing because multiple test specimens can be extracted per Superpave gyratory-compacted (SGC) sample. This study seeks to optimize the procedure used for the extraction of small specimens from SGC samples for dynamic modulus and cyclic fatigue tests. To this end, small cylindrical specimens were cored horizontally and vertically from SGC samples and subjected to performance testing. The dynamic modulus and fatigue test results indicate that the effects of anisotropy are minimal. However, all of the horizontally extracted small specimens exhibited fatigue failure at the specimen ends, outside the range of the gauges; the failure was likely due to the peripheral air void gradients in the SGC samples. Therefore, the authors concluded that small specimens should be vertically cored from SGC samples for the laboratory fabrication of small specimens. Specifically, four small specimens were cored vertically from the inner 100 mm of SGC samples where the air void content is relatively uniform. Four mixtures with different nominal maximum aggregate sizes (NMASs) were used to prepare small specimens using the proposed extraction procedure. These specimens were subjected to dynamic modulus and cyclic fatigue testing. The results demonstrate an increase in specimen-to-specimen variability with an increase in NMAS, which also is expected in large specimen testing.


2018 ◽  
Vol 34 ◽  
pp. 01021
Author(s):  
Rosnawati Buhari ◽  
Mohd Ezree Abdullah ◽  
Mohd Khairul Ahmad ◽  
Saiful Azhar Tajudin ◽  
Siti Khatijah Abu Bakar

This study aims to evaluate the fatigue performance of modified asphalt mixture using Indirect Tensile Fatigue Test. Titanium Dioxide (TiO2) powder in a form of rutile was used for producing asphalt concrete with lower mixing and compaction temperature compared to conventional hot mix asphalt without reducing its physical and mechanical also resistance to fatigue. The characteristic of the asphalt and modified asphalt was evaluated using penetration test, softening test and rotational viscosity test. Titanium dioxide of 2%, 4%, 6%, 8% and 10% by weight of asphalt has been incorporated into unaged 80/100 asphalt mix in order to improvise its performance and to fulfill the objectives of this experimental study. As a result, TiO2 as an additive is potential to decrease the penetration and increasing the softening point of the asphalt. In terms of fatigue performance testing, addition TiO2 additive does help in improving the fatigue properties as it shows greater result than the control asphalt. In conclusion, TiO2 is great in improving fatigue properties.


Materials ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 342 ◽  
Author(s):  
Weiguang Zhang ◽  
Shihui Shen ◽  
Ryan Douglas Goodwin ◽  
Dalin Wang ◽  
Jingtao Zhong

Semi-flexible composite mixture (SFCM) is developed based on a unique material design concept of pouring cement mortar into the voids formed by open graded asphalt mixture. It combines the flexibility of asphalt concrete and the stiffness of Portland cement concrete and has many advantages comparing to conventional roadway paving materials. The main objective of this paper was to evaluate the engineering properties of SFCM and assess the constructability of the SFCM. A slab SFCM sample was fabricated in the laboratory to simulate the filling of cement mortar in the field. Performance testing was carried out by indirect tensile (IDT) test because it was found to be able to correlate with the field performance of asphalt mixtures at low, intermediate, and high temperatures. They were used in this study to evaluate the thermal cracking, fatigue, rutting, as well as moisture resistance of SFCM. A control hot mix asphalt (HMA) mixture was used to compare with the results of SFCM. Based on the testing results, it was found that the designed SFCM showed good filling capability of cement mortar. SFCM had higher dynamic modulus than the control HMA. It had good resistance to rutting and moisture damage. Based on fracture work, SFCM showed better resistance to thermal cracking while lower resistance to fatigue cracking.


Author(s):  
Peyman Barghabany ◽  
Wei Cao ◽  
Louay N. Mohammad ◽  
Samuel B. Cooper ◽  
Samuel B. Cooper

Because of limited amounts of natural resources, reclaimed asphalt pavement (RAP) has gained popularity in the asphalt pavement industry to meet sustainability requirements in asphalt pavement. Concerns have been raised in relation to the intermediate temperature cracking performance of asphalt mixtures containing RAP. The objective of this study was to evaluate the intermediate temperature cracking resistance of asphalt mixtures and recovered asphalt binders containing RAP. Seven plant-produced asphalt mixtures from three transportation agencies with various RAP contents and the extracted asphalt binders were evaluated with respect to intermediate temperature cracking resistance. Asphalt binder experiments included chemical and rheological characterization of recovered asphalt binders. Chemical characterization consisted of Fourier transform infrared spectroscopy and saturates/aromatics/resins/asphaltenes component analysis. Linear amplitude sweep and time sweep tests were also performed to characterize the rheological properties of asphalt binders. Asphalt mixture experiments included four-point bending beam fatigue and semi-circular bend tests. Results indicated that, as expected, asphalt mixtures with high RAP contents resulted in asphalt binders and mixtures with reduced cracking resistance. Relationships between the asphalt binder chemical and rheological parameters and asphalt mixture cracking resistance were also investigated. Asphalt binder rheological and chemical parameters were well correlated. Asphalt binder rheological parameters showed reasonable to strong relationships with the four-point bending beam fatigue test result. The work presented in this paper is part of FHWA Transportation Pooled Fund Project TPF-5(294) “Develop Mix Design and Analysis Procedure for Asphalt Mixtures Containing High RAP and/or RAS Contents.”


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