Establishing Linear Viscoelastic Conditions for Asphalt Binders

2000 ◽  
Vol 1728 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Mihai O. Marasteanu ◽  
David A. Anderson
Keyword(s):  
Single Point ◽  
Superposition Principle ◽  
Asphalt Binder ◽  
Testing Procedure ◽  
Constitutive Relationship ◽  
Asphalt Binders ◽  
Direct Tension ◽  
Linear Viscoelastic Material ◽  
Frequency Domains ◽  
Linear Viscoelastic

The linear viscoelastic regime is defined in terms of the constitutive relationship between the stress and the strain. The set of equations that define the fundamental linear viscoelastic material properties in the time and frequency domains and their relationship to one another is based on the validity of the linearity principle. A material must obey two simultaneous conditions to be linear viscoelastic: the homogeneity (also called proportionality) condition and the superposition principle. On the basis of these considerations a testing procedure was developed to check linear viscoelastic conditions for tests performed on asphalt binders with the dynamic shear rheometer (DSR), the bending beam rheometer (BBR), and direct tension (DT). The testing procedure for the DSR requires performing strain sweeps and multiwave single-point tests. For the BBR, tests performed using different constant loads are required. In addition, the recovery part of the specification test is recorded. For the DT, tests performed at different strain rates and relaxation tests performed at different strain levels are required. When applied to asphalt binder data, the testing procedure found no departure from viscoelastic conditions for the DSR and BBR test data. However, the DT procedure indicated a departure from linear viscoelastic conditions.

Dynamic Viscoelastic Properties of SBS Modified Asphalt Based on DSR Testing

2012 ◽  
Vol 598 ◽  
pp. 473-476 ◽  
Author(s):  
Yong Mei Guo ◽  
Wei Chen
Keyword(s):  
Complex Modulus ◽  
Superposition Principle ◽  
Asphalt Binder ◽  
Asphalt Binders ◽  
Frequency Range ◽  
Master Curves ◽  
Temperature Property ◽  
Low Frequencies ◽  
High Temperature Property ◽  
Frequency Sweeps

Five SBS modified asphalts and one base asphalt were selected to carry out frequency sweeps over a wider frequency range using the dynamic shear rheometer (DSR). Six asphalt binders were subjected to sinusoidal loading at 30°C-90°C within the linear viscoelastic limits, and master curves of complex modulus (G*) and phase angle (δ) could be constructed by means of the time-temperature superposition principle (TTSP). The results show that the G* values of SBS modified asphalts are significantly greater than those of base asphalt at low frequencies, but are slightly smaller at high frequencies. Compared with the base asphalt, SBS modified asphalts have narrower master curves of complex modulus, and their phase angles are much smaller within the whole frequency range. This indicates that various properties of SBS modified asphalts, such as high-temperature property, low-temperature property, temperature susceptibility and elastic recoverability, are superior to those of the base asphalt. The G* values of the rolling thin-film oven (RTFO) aged asphalt are larger than those of the unaged asphalt in the whole range of frequencies, demonstrating that the anti-rutting performance of asphalt binder is improved after short-term aging.

scholarly journals High-Temperature Performance Evaluation of Asphaltenes-Modified Asphalt Binders

Molecules ◽  
2020 ◽  
Vol 25 (15) ◽  
pp. 3326
Author(s):  
Amirhossein Ghasemirad ◽  
Nura Bala ◽  
Leila Hashemian
Keyword(s):  
High Temperatures ◽  
High Performance ◽  
Asphalt Binder ◽  
Viscoelastic Behavior ◽  
Asphalt Binders ◽  
Performance Grade ◽  
Modified Binders ◽  
Linear Viscoelastic Behavior ◽  
Linear Viscoelastic ◽  
Gravity Driven

Asphalt binder comprises four main fractions—asphaltenes (A), saturates (S), aromatics (A), and resins (R)—referred to as “SARA”. Asphaltenes plays an important role in determining the linear viscoelastic behavior of asphalt binders. In this research, asphaltenes are added as a distinct modifier to improve the performance properties of asphalt binder. The modified binders are aged using a rolling thin film oven. A dynamic shear rheometer is then used to measure the rheological properties of the binders at high temperatures. Changes in the chemical composition of the modified binders are also studied through the determination of SARA fractions, using precipitation and gravity-driven chromatography methods. The rheological results show that asphaltenes improve the stiffness and elasticity of asphalt binder. It is also shown that the addition of asphaltenes raises the high Performance grade (PG) temperature of the asphalt binder, with every 6% of asphaltenes added resulting in a one-interval increase in high PG temperature grade. SARA analysis shows that the increase in polar fraction content due to the addition of asphaltenes causes the stiffness, elasticity, and viscosity of asphalt binders to increase. The results indicate that asphaltenes are an effective yet inexpensive additive to improve asphalt binder properties at high temperatures.

Development of Superpave Direct Tension Test Device

1997 ◽  
Vol 1586 (1) ◽  
pp. 32-39 ◽  
Author(s):  
Raj Dongré ◽  
John D’Angelo ◽  
Steve McMahon
Keyword(s):  
Asphalt Binder ◽  
Tension Test ◽  
Asphalt Binders ◽  
Temperature Control System ◽  
Materials Testing ◽  
Direct Tension ◽  
Direct Tension Test ◽  
New Device ◽  
Failure Properties ◽  
User Friendly

The redesign and evaluation of the Superpave direct tension test (DTT) are described. The prototype of the DTT device was developed during the Strategic Highway Research Program (SHRP). The DTT device, an integral part of the new Superpave asphalt binder specification, was developed to test asphalt binders and determine their failure properties, such as the stress and strain at failure. The strain at failure is used in the Superpave asphalt binder specification to determine the lowest temperature at which the asphalt can be used to avoid low-temperature thermal cracking. When the SHRP program was completed, an affordable specification version of the prototype SHRP-DTT device was introduced for field implementation. Unfortunately, this version was plagued with mechanical problems, producing excessive variability and inconsistency in data. The device also was less user-friendly than other test devices that were being implemented for the asphalt binder specification. These problems led to implementation delays and difficulties. The problems were addressed by FHWA in cooperation with Instron Corporation of Canton, Massachusetts (a manufacturer of materials testing equipment). On the basis of recommendations made by FHWA, Instron developed a new, easy-to-use specification-type DTT device. This device is compact (approximately one-tenth the size of the original) and uses a fluid-based temperature control system similar to that used in the bending beam rheometer. The new device also employs feedback elongation (strain) rate control. However, unlike the previous device, the new DTT uses an extensometer between the loading pins instead of a laser to measure elongation (strain). The evaluation and resulting recommendations by FHWA, which led to the development of the new specification-type devices are discussed. The repeatability and testing protocols also are discussed.

Considerations for using the 4 mm Plate Geometry in the Dynamic Shear Rheometer for Low Temperature Evaluation of Asphalt Binders

2019 ◽  
Vol 2673 (11) ◽  
pp. 649-659 ◽  
Author(s):  
Ramez Hajj ◽  
Angelo Filonzi ◽  
Syeda Rahman ◽  
Amit Bhasin
Keyword(s):  
Low Temperature ◽  
Asphalt Binder ◽  
Asphalt Binders ◽  
Asphalt Pavements ◽  
Dynamic Shear ◽  
Dynamic Shear Rheometer ◽  
Reclaimed Asphalt ◽  
Load Response ◽  
Linear Viscoelastic ◽  
Analytical Approaches

The low-temperature properties of asphalt binder have attracted attention in recent years thanks to an increase in the use of reclaimed asphalt pavements (RAP). Traditional methods to evaluate the low-temperature properties of the binder require a large amount of binder that needs to be recovered from RAP samples for testing with a Bending Beam Rheometer (BBR). To economize on sample size for RAP materials and also for emulsion residues, previous researchers have explored the potential of using a 4 mm diameter specimen with a Dynamic Shear Rheometer (DSR) in lieu of the BBR. To compare results from frequency sweep tests conducted using the DSR with results from the BBR, data from the former need to be converted to time domain and subsequently from a shear load response to an axial load response. Previous research studies have developed methods to accomplish these two conversions to compare data from the DSR with data from the BBR. The objective of this study is to examine some of these methods from the literature and elsewhere based on the principles of linear viscoelastic interconversion using a set of 11 different binders. Results using different analytical approaches from this study show that the DSR has good repeatability and verify that it can be used as a surrogate for the BBR to determine low-temperature properties, while exercising some caution with some of the assumptions related to Poisson’s ratio.

Creep Compliance of Polymer-Modified Asphalt, Asphalt Mastic, and Hot-Mix Asphalt

2003 ◽  
Vol 1829 (1) ◽  
pp. 33-38 ◽  
Author(s):  
Ota Vacin ◽  
Jiri Stastna ◽  
Ludo Zanzotto
Keyword(s):  
Creep Compliance ◽  
Superposition Principle ◽  
Asphalt Binder ◽  
Tensile Creep ◽  
Asphalt Binders ◽  
Simple Relationship ◽  
Modified Asphalt ◽  
Asphalt Mastic ◽  
Polymer Modified Asphalt ◽  
Time Temperature Superposition Principle

The possibility of using commercial rheometers for comprehensive testing of asphalt binders, asphalt mastics, and hot-mix asphalts (HMA) is explored. Samples of one polymer-modified asphalt, its mix with fine mineral filler (mastic), and one HMA prepared with the same modified asphalt as binders were tested in the dynamic shear rheometer (DSR) and the bending beam rheometer (BBR). All tested materials can be characterized by their discrete relaxation and retardation spectra (under the condition of small deformations). DSR testing was performed in the plate–plate and the torsion bar geometry. From the obtained relaxation and retardation spectra, the shear compliance, J(t), was calculated and compared with the tensile creep compliance, D(t), measured in BBR (both creep and recovery experiments were run). A simple relationship between J(t) and D(t) was found for the asphalt binder and the asphalt mastic. In the case of HMA, the bulk compliance, B(t), contributes to D(t) at short and long times. Both the Boltzmann superposition principle and the time–temperature superposition principle hold very well for all tested materials at low temperatures. There are qualitative differences, in the rheological behavior, of the asphalt binder and asphalt mastic on one side and the HMA on the other. These differences can be seen in dynamic (DSR) as well as in transient (BBR) experiments.

Field Validation of New Superpave Low-Temperature Binder Specification Procedure: Performance Data from Pennsylvania Test Sections

2000 ◽  
Vol 1728 (1) ◽  
pp. 60-67 ◽  
Author(s):  
Raj Dongré ◽  
Mark G. Bouldin ◽  
Dean A. Maurer
Keyword(s):  
Low Temperature ◽  
Asphalt Binder ◽  
Asphalt Binders ◽  
Direct Tension ◽  
Transverse Cracking ◽  
Performance Grade ◽  
Temperature Performance ◽  
Test Road ◽  
Low Temperature Performance ◽  
And Performance

A new specification procedure was proposed recently to determine the low-temperature performance grade of asphalt binders. This new procedure uses bending beam rheometer (BBR) and direct tension test (DTT) data at two temperatures to determine the low-temperature grade of an asphalt binder. A study was conducted to validate this procedure by using asphalt binder retained samples from the widely published test road in Pennsylvania. This road was constructed in 1976 in Elk County, and performance—including low-temperature transverse cracking index—was monitored over 6 years. In this study, the retained binder samples from test sections T-1 to T-6 were tested with the BBR and the new Superpave® DTT. The data from these two tests were analyzed to obtain critical cracking temperatures and low-temperature performance grades. Results indicate that the new procedure correctly predicts the temperature at which cracking was observed in the field.

Modeling of Tread Block Contact Mechanics Using Linear Viscoelastic Theory3

2008 ◽  
Vol 36 (3) ◽  
pp. 211-226 ◽  
Author(s):  
F. Liu ◽  
M. P. F. Sutcliffe ◽  
W. R. Graham
Keyword(s):  
High Speed ◽  
Slip Rate ◽  
Material Model ◽  
Contact Forces ◽  
Block Modeling ◽  
Rate Dependent ◽  
Linear Viscoelastic Material ◽  
Linear Viscoelastic ◽  
The Impact ◽  
Good Agreement

Abstract In an effort to understand the dynamic hub forces on road vehicles, an advanced free-rolling tire-model is being developed in which the tread blocks and tire belt are modeled separately. This paper presents the interim results for the tread block modeling. The finite element code ABAQUS/Explicit is used to predict the contact forces on the tread blocks based on a linear viscoelastic material model. Special attention is paid to investigating the forces on the tread blocks during the impact and release motions. A pressure and slip-rate-dependent frictional law is applied in the analysis. A simplified numerical model is also proposed where the tread blocks are discretized into linear viscoelastic spring elements. The results from both models are validated via experiments in a high-speed rolling test rig and found to be in good agreement.

scholarly journals Material Properties and Environmental Benefits of Hot-Mix Asphalt Mixes Including Local Crumb Rubber Obtained from Scrap Tires

Environments ◽  
2021 ◽  
Vol 8 (6) ◽  
pp. 47
Author(s):  
Lim Min Khiong ◽  
Md. Safiuddin ◽  
Mohammad Abdul Mannan ◽  
Resdiansyah
Keyword(s):  
Asphalt Binder ◽  
Crumb Rubber ◽  
Environmental Benefits ◽  
Asphalt Binders ◽  
Rubber Content ◽  
Scrap Tires ◽  
Asphalt Mixes ◽  
Temperature Resistance ◽  
Modified Asphalt ◽  
Marshall Stability

This paper presents the results of a laboratory-based experimental investigation on the properties of asphalt binder and hot-mix asphalt (HMA) mixes modified by locally available crumb rubber, which was used as a partial replacement of asphalt by weight. In this study, fine crumb rubber with a particle size in the range of 0.3–0.6 mm, obtained from scrap tires, was added to the asphalt binder through the wet process. Crumb rubber contents of 5%, 10%, 15%, and 19% by weight of asphalt were added to the virgin binder in order to prepare the modified asphalt binder samples, while the unmodified asphalt binder was used as the control sample. The crumb rubber modified binder samples were examined for measuring viscosity indirectly using the penetration test, and temperature resistance using the softening point test. Later, both the modified and unmodified asphalt binders were used to produce HMA mixes. Two categories of HMA mix commonly used in Malaysia—namely, AC 14 (dense-graded) and SMA 14 (gap-graded)—were produced using the modified asphalt binders containing 5%, 10%, 15%, and 19% crumb rubber. Two AC 14 and SMA 14 control mixes were also produced, incorporating the unmodified asphalt binder (0% crumb rubber). All of the AC 14 and SMA 14 asphalt mixes were examined in order to determine their volumetric properties, such as bulk density, voids in total mix (VTM), voids in mineral aggregate (VMA), and voids filled with asphalt (VFA). In addition, the Marshall stability, Marshall flow, and stiffness of all of the AC 14 and SMA 14 mixes were determined. Test results indicated that the modified asphalt binders possessed higher viscosity and temperature resistance than the unmodified asphalt binder. The viscosity and temperature resistance of the asphalt binders increased with the increase in their crumb rubber content. The increased crumb rubber content also led to improvements in the volumetric properties (bulk density, VTM, VMA, and VFA) of the AC 14 and SMA 14 mixes. In addition, the performance characteristics of the AC 14 and SMA 14 mixes—such as Marshall stability, Marshall flow, and stiffness—increased with the increase in crumb rubber content. However, the AC 14 mixes performed much better than the SMA 14 mixes. The overall research findings suggest that crumb rubber can be used to produce durable and sustainable HMA mixes, with manifold environmental benefits, for use in flexible pavements carrying the heavy traffic load of highways.

scholarly journals Recent advances in characterizing the “bee” structures and asphaltene particles in asphalt binders

2020 ◽  
Vol 13 (6) ◽  
pp. 697-706
Author(s):  
Yuhong Wang ◽  
Kecheng Zhao ◽  
Fangjin Li ◽  
Qi Gao ◽  
King Wai Chiu Lai
Keyword(s):  
Near Field ◽  
Asphalt Binder ◽  
Optical Microscope ◽  
Asphalt Binders ◽  
Zero Shear Viscosity ◽  
Surface Features ◽  
Asphaltene Content ◽  
Scanning Transmission ◽  
Before And After ◽  
Binder Aging

AbstractThe microscopic surface features of asphalt binders are extensively reported in existing literature, but relatively fewer studies are performed on the morphology of asphaltene microstructures and cross-examination between the surface features and asphaltenes. This paper reports the findings of investigating six types of asphalt binders at the nanoscale, assisted with atomic force microscopy (AFM) and scanning transmission electron microscopy (STEM). The surface features of the asphalt binders were examined by using AFM before and after being repetitively peeled by a tape. Variations in infrared (IR) absorbance at the wavenumber around 1700 cm−1, which corresponds to ketones, were examined by using an infrared s-SNOM instrument (scattering-type scanning near-field optical microscope). Thin films of asphalt binders were examined by using STEM, and separate asphaltene particles were cross-examined by using both STEM and AFM. In addition, connections between the microstructures and binder’s physicochemical properties were evaluated. The use of both microscopy techniques provide comprehensive and complementary information on the microscopic nature of asphalt binders. It was found that the dynamic viscosities of asphalt binders are predominantly determined by the zero shear viscosity of the corresponding maltenes and asphaltene content. Limited samples also suggest that the unique bee structures are likely related to the growth of asphaltene content during asphalt binder aging process, but more asphalt binders from different crude sources are needed to verify this finding.

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