Laboratory Evaluation of a Plant-Produced High Polymer–Content Asphalt Mixture

2017 ◽  
Vol 2631 (1) ◽  
pp. 144-152 ◽  
Author(s):  
Benjamin F. Bowers ◽  
Stacey D. Diefenderfer ◽  
Brian K. Diefenderfer
Keyword(s):  
Asphalt Binder ◽  
Asphalt Mixture ◽  
Aggregate Size ◽  
Asphalt Binders ◽  
Laboratory Evaluation ◽  
Maximum Aggregate Size ◽  
Polymer Content ◽  
High Polymer ◽  
Modified Binder ◽  
Virginia Department

Reflective cracking in asphalt overlays placed over jointed concrete pavements is of major concern in Virginia, as well as nationally, and has generated interest in various reflective crack mitigation techniques that are easy to implement. One technique is the use of binder modifiers, such as asphalt rubber, polymer-modified asphalt binders, or high polymer–content (HP) modified binders. In the summer of 2014, the Virginia Department of Transportation placed an HP asphalt mixture produced by using an asphalt binder that contained approximately 7.5% styrene-butadiene-styrene polymer in a trial section within a subdivision as a low-risk means to assess constructability and laboratory performance. The HP mixture was evaluated in comparison with a typical surface asphalt mixture with a 9.5-mm nominal maximum aggregate size, as a control. Testing was performed on specimens fabricated from reheated control and HP mixture samples, as well as on specimens fabricated from site-compacted samples and road cores of the HP mixture. In addition, binder grading was performed on the control binder and modified binder. The HP binder was significantly more elastic than the control binder. Comparable dynamic moduli were found for reheated mixture specimens, although site-compacted and road core specimens from the HP mixture had lower stiffness than the control mixture. The HP mixture performed better in rutting and in fatigue. The Texas overlay test indicated similar crack resistance between the two mixtures; however, measured loads of the HP specimens were nearly half those of the control specimens. The results of laboratory testing indicated that the mixture incorporating the HP binder should have a far greater fatigue life and rut resistance than the control mixture.

EVALUATION ON THE PERFORMANCE OF AGED ASPHALT BINDER AND MIXTURE UNDER VARIOUS AGING METHODS

2015 ◽  
Vol 77 (23) ◽  
Author(s):  
Mohd Khairul Idham ◽  
Mohd Rosli Hainin ◽  
M. Naqiuddin M. Warid ◽  
Noor Azah Abdul Raman ◽  
Rosmawati Mamat
Keyword(s):  
Permanent Deformation ◽  
Asphalt Binder ◽  
Asphalt Mixture ◽  
Aggregate Size ◽  
Maximum Aggregate Size ◽  
Asphaltic Concrete ◽  
Air Exposure ◽  
Stiffness Modulus ◽  
Aged Asphalt

Hot mix asphalt (HMA) pavement encounter short and long term aging throughout the service life. Laboratory aging is the method used to simulate field aging process of HMA pavement. This study was undertaken to determine the long term effect of different binder and mixture laboratory aging methods on HMA (binder aging and mixture aging). Three types of HMA mixtures were prepared for this study namely Asphaltic Concrete with 10 mm nominal maximum aggregate size (AC 10), Asphaltic Concrete 14 mm (AC 14) and Asphaltic Concrete 28 mm (AC 28). These specimens were conditioned with nine different methods and durations.  Resilient modulus test was carried out at 40˚C as an initial indicator of the specimen performance. Permanent deformation of the same specimens was then evaluated by dynamic creep test. Generally, the aged asphalt binder specimens have higher resilient and stiffness modulus compared to aged asphalt mixture specimens. In addition, aged binder specimens have a lower permanent strain which indicates higher resistance to permanent deformation. This study also found that high resilient and stiffness modulus of specimens is attributed by different in heating frequency, temperature, air exposure and binder content of the mixtures.

Laboratory Evaluation of Mixture Type on Highly Modified Asphalt Mixtures in Virginia

2018 ◽  
Vol 2672 (28) ◽  
pp. 59-68
Author(s):  
Benjamin F. Bowers
Keyword(s):  
Asphalt Binder ◽  
Aggregate Size ◽  
Asphalt Mixtures ◽  
Laboratory Evaluation ◽  
Maximum Aggregate Size ◽  
Air Voids ◽  
Modified Asphalt ◽  
Modified Asphalt Binder ◽  
Dynamic Modulus Test ◽  
Scb Specimen

The work presented attempts to address reflective cracking of asphalt-surfaced pavements through binder modification with a highly polymer (HP)-modified asphalt binder. Nine asphalt mixtures ranging from fine dense-graded mixtures to stone matrix asphalt (SMA) mixtures were investigated with conventional polymer modified binders and HP binder. The dynamic modulus test, overlay test (OT), and semi-circular bend (SCB) test were used to evaluate the mixtures. In the cracking tests, HP mixtures outperformed the conventionally modified control mixtures for the same mixture type. For HP mixtures, in general, SMA mixtures performed better in the cracking test than dense-graded mixtures. One of the dense-graded mixtures having larger nominal maximum aggregate size (NMAS) performed better than the mixture with a smaller NMAS, whereas the other having a larger NMAS was not significantly different in crack testing. Further, a discussion on the calculation of bulk specific gravity and percent air voids in a cut OT and SCB specimen using saturated surface dry or vacuum sealing methods is presented.

scholarly journals Characterization of neat and modified asphalt binders and mixtures in relation to permanent deformation

2019 ◽  
Vol 26 (1) ◽  
pp. 379-387
Author(s):  
Iuri S. Bessa ◽  
Márcia M. Takahashi ◽  
Kamilla L. Vasconcelos ◽  
Liedi L. B. Bernucci
Keyword(s):  
Permanent Deformation ◽  
Asphalt Binder ◽  
Asphalt Mixture ◽  
Asphalt Mixtures ◽  
Asphalt Binders ◽  
Rutting Resistance ◽  
Modified Asphalt ◽  
Recoverable Compliance ◽  
Modified Binder ◽  
Deformation Tests

AbstractThe addition of polymers on asphalt binders aims to enhance their performance, especially at high temperatures, which correspond to rutting resistance. The Superpave rutting parameter (|G*|/sinδ) has been considered to be inadequate to characterize the performance of modified materials, therefore the Multiple Stress Creep and Recovery (MSCR) test was developed, providing the parameter non-recoverable compliance (Jnr). This research has the main objective of correlating asphalt binders performance-based characterization with rutting resistance of asphalt mixtures, and presents results obtained for one conventional (50/70 penetration grade) and two modified asphalt binders (2.1% RET and 1.9% RET) regarding their rheological characteristics. With the use of the dynamic shear rheometer (DSR), master curves and MSCR results were obtained for the three binders. In addition, permanent deformation tests were performed on the asphalt mixtures by means of laboratory traffic simulation. The rutting characterization indicated higher permanent deformation resistance for the modified binders for the asphalt binder and the asphalt mixture testing. The main conclusions were that the use of modified binder reduced in approximately 50% the Jnr values and the rut depth; also, the asphalt binders’ characteristics were able to predict the asphalt mixtures rutting resistance.

Multi-Level Laboratory Performance Evaluation of Conventional and High Polymer-Modified Asphalt Mixtures

2021 ◽  
pp. 036119812110566
Author(s):  
Jhony Habbouche ◽  
Ilker Boz ◽  
Brian K. Diefenderfer ◽  
Sungho Kim
Keyword(s):  
Comprehensive Evaluation ◽  
Asphalt Binder ◽  
Asphalt Mixtures ◽  
Asphalt Binders ◽  
High Polymer ◽  
Binder Type ◽  
Polymer Modified Asphalt ◽  
Virginia Department ◽  
Long Term Performance ◽  
Term Performance

Asphalt concrete (AC) overlays have been one of the most common treatments used by the Virginia Department of Transportation (VDOT) for maintaining/rehabilitating pavements. However, when the overlay is placed on existing composite pavements or cracked AC pavements, differential movements across any cracks or joints can result in physical tearing of the AC overlay. Thus, the long-term performance of many AC overlays will highly depend on their ability to resist cracking. The purpose of this study was to assess the viability of using high polymer-modified (HP) AC mixtures in Virginia as a crack mitigation technique or when deemed appropriate as a tool for increased resistance to rutting and cracking on higher volume facilities. Another objective was to assess the ability of various testing protocols to discern the performance of pavements through a comprehensive evaluation of three conventional polymer-modified (PMA) and five HP field-produced mixtures placed in Virginia. This included laboratory testing at multiple levels of complexity (basic, intermediate, and advanced) on collected asphalt binders, plant-produced asphalt mixtures, and field cores. The performance characteristics of PMA and HP mixes were evaluated in the laboratory in relation to durability and resistance to rutting and cracking. Based on the mixes tested, stone matrix asphalt (SMA) mixes showed better performance than dense-graded surface mixes (SM) regardless of the asphalt binder type. Moreover, HP mixes showed better performance than PMA mixes regardless of the mixture type. Overall, SMA-HP mixes showed the most promising performance among all evaluated mixes.

scholarly journals Enhanced Dry Process Method for Modified Asphalt Containing Plastic Waste

2021 ◽  
Vol 8 ◽  
Author(s):  
Hasanain Radhi Radeef ◽  
Norhidayah Abdul Hassan ◽  
Ahmad Razin Zainal Abidin ◽  
Mohd Zul Hanif Mahmud ◽  
Nur Izzi Md. Yusoffa ◽  
...  
Keyword(s):  
Resilient Modulus ◽  
Asphalt Binder ◽  
Asphalt Mixture ◽  
Aggregate Size ◽  
Plastic Waste ◽  
Asphalt Mixtures ◽  
Maximum Aggregate Size ◽  
Dry Process ◽  
Modified Asphalt ◽  
And Performance

In recent years, the proliferation of plastic waste has become a global problem. A potential solution to this problem is the dry process, which incorporates plastic waste into asphalt mixtures. However, the dry process often has inconsistent performance due to poor interaction with binder and improper distribution of plastic waste particles in the mixture skeleton. This inconsistency may be caused by inaccurate mixing method, shredding size, mixing temperature and ingredient priorities. Thus, this study aims to improve the consistency of the dry process by comparing the control asphalt mixture and two plastic waste-modified asphalt mixtures prepared using the dry process. This study used crushed granite aggregate with the nominal maximum aggregate size of 14 mm whereas the shredded plastic bag is in the range of 5–10 mm. Quantitative sieving analysis and performance tests were carried out to examine the effects of plastic waste added into the asphalt mixture. The volumetric and performance properties combined with image analysis of the modified mixtures were obtained and compared with the control mixture. In addition, the moisture damage, resilient modulus, creep deformation and rutting were evaluated. This study also highlighted in detail the distribution of plastic particles in the final skeleton of the asphalt mixture. Based on the analysis, an enhanced dry process of mixing procedure was proposed and evaluated. Results showed that the addition of plastic particles using the conventional dry process leads to the deviation in the aggregate structure as high plastic content is added. Furthermore, the enhanced dry process developed in this study presents substantial enhancement in the asphalt performance, particularly with plastic waste that accounts for 20% of the weight of the asphalt binder.

Effect of Binder Types on Engineering Properties and Performance of Porous Asphalt Concrete

2012 ◽  
Vol 2293 (1) ◽  
pp. 55-62 ◽  
Author(s):  
Jian-Shiuh Chen ◽  
Yang-Chou Sun ◽  
Min-Chih Liao ◽  
Chien-Chung Huang
Keyword(s):  
Asphalt Concrete ◽  
High Speed ◽  
Asphalt Binder ◽  
Aggregate Size ◽  
High Viscosity ◽  
Engineering Properties ◽  
Maximum Aggregate Size ◽  
Porous Asphalt ◽  
Modified Binder ◽  
Porous Asphalt Concrete

Porous asphalt concrete (PAC) has an open-graded aggregate mixture to yield high air voids; PAC is mainly applied to the surface drainage layer on high-speed trafficked highway pavements. The objective of the study was to investigate the effect of binder types on the engineering properties and field performance of PAC mixtures. Three binder types were selected for a 19-mm nominal maximum aggregate size gradation: conventional asphalt AR-80, polymer-modified asphalt, and high-viscosity asphalt. A series of laboratory tests were conducted to evaluate the engineering properties of the PAC mixture, including permeability, resistance to draindown, resistance to disintegration, resistance to rutting, and resistance to indirect traction. A 3-km in-service test road was constructed to monitor the performance of PAC pavements using these three binders. Polymer-modified binder was shown to minimize abrasion loss and enhance the durability of the PAC mixture. Test results indicated that the use of polymer-modified binder, instead of unmodified binder, reduced rutting and raveling. When the mixture contained high-viscosity binder, it showed the best performance in the field. Field measurements indicated improved drainage as a result of replacement of the conventional asphalt AR-80 binder with the polymer-modified and high-viscosity binders. PAC pavement surfaces provided good frictional characteristics once the asphalt binder film was worn from the aggregate.

scholarly journals Development of a 4.75 mm asphalt mixture design for Implementation in Louisiana DOTD Specifications

2020 ◽  
Vol 13 (6) ◽  
pp. 637-644
Author(s):  
Saman Salari ◽  
Samuel Cooper ◽  
Louay N. Mohammad ◽  
Peyman Barghabany
Keyword(s):  
Comprehensive Evaluation ◽  
Asphalt Binder ◽  
Asphalt Mixture ◽  
Performance Testing ◽  
Aggregate Size ◽  
Asphalt Mixtures ◽  
Maximum Aggregate Size ◽  
Construction Costs ◽  
The Cost ◽  
Wheel Tracking

AbstractThe Louisiana Department of Transportation and Development (DOTD) and other state agencies are continuously looking for techniques to reduce roadway maintenance and construction costs. A common consideration is to introduce asphalt mixtures with a smaller nominal maximum aggregate size (NMAS) for utilization in roadways. In a previous study, DOTD concluded that mixtures with a 4.75 mm NMAS provided acceptable performance as a surface layer. Excessive stockpiles of unused smaller aggregates can result in an economically competitive source to be consi dered for asphalt mixtures. The DOTD developed mixtures with four aggregate types and two binder types. A comprehensive evaluation of performance was conducted through volumetric and mechanistic testing. Performance testing consisted of the Loaded Wheel Tracking (LWT) test to determine rutting resistance, Semi-Circular Bend (SCB) test to evaluate intermediate temperature cracking resistance, and dynamic modulus (E*) to ascertain the stiffness at intermediate temperatures. As expected, asphalt binder grade, aggregate type and mixture composition affected the performance of mixtures evaluated. Gravel mixtures were susceptible to cracking, while limestone mixtures were susceptible to rutting. An economic analysis was conducted to determine the viability of 4.75 mm mixtures. The cost per ton of 4.75 mm mixtures in Louisiana was higher than conventional 12.5 mm mixtures. However, when considering the lift thickness of potential overlays, the 4.75 mm aggregate mixtures became more viable. Further, a life-cycle analysis of a designed pavement using AASHTO Pavement-ME was performed to compare the lifetime durability of the 4.75 mm NMAS mixtures to a conventional 12.5 mm mixture.

A Hybrid Model to Predict the Gyratory Compaction of Hot Mixed Asphalt

2019 ◽  
Author(s):  
Teng Man
Keyword(s):  
Hybrid Model ◽  
Asphalt Binder ◽  
Asphalt Mixture ◽  
Aggregate Size ◽  
Asphalt Mixtures ◽  
Compaction Process ◽  
Particle Rearrangement ◽  
Compaction Behavior ◽  
Grain Size Distributions ◽  
Gyratory Compaction

The compaction of asphalt mixture is crucial to the mechanical properties and the maintenance of the pavement. However, the mix design, which based on the compaction properties, remains largely on empirical data. We found difficulties to relate the aggregate size distribution and the asphalt binder properties to the compaction behavior in both the field and laboratory compaction of asphalt mixtures. In this paper, we would like to propose a simple hybrid model to predict the compaction of asphalt mixtures. In this model, we divided the compaction process into two mechanisms: (i) visco-plastic deformation of an ordered thickly-coated granular assembly, and (ii) the transition from an ordered system to a disordered system due to particle rearrangement. This model could take into account both the viscous properties of the asphalt binder and grain size distributions of the aggregates. Additionally, we suggest to use the discrete element method to understand the particle rearrangement during the compaction process. This model is calibrated based on the SuperPave gyratory compaction tests in the pavement lab. In the end, we compared the model results to experimental data to show that this model prediction had a good agreement with the experiments, thus, had great potentials to be implemented to improve the design of asphalt mixtures.

Determining Optimum Carbon Nanotubes Content for Asphalt Mixture in Road Pavements

2021 ◽  
Vol 1023 ◽  
pp. 121-126
Author(s):  
Van Bach Le ◽  
Van Phuc Le
Keyword(s):  
Carbon Nanotubes ◽  
Asphalt Pavement ◽  
Asphalt Binder ◽  
Asphalt Mixture ◽  
Construction Cost ◽  
Asphalt Mixtures ◽  
Static Modulus ◽  
Pavement Construction ◽  
Modified Binder ◽  
Marshall Stability

Although small amount of binder in asphalt concrete mixture may commonly range from 3.5 to 5.5% of total mixture as per many international specifications, it has a significant impact on the total cost of pavement construction. Therefore, this paper investigated the effects of five carbon nanotubes contents of 0.05%, 0.1%, 0.15%, 0.2%, 0.25% by asphalt weight as an additive material for binder on performance characteristics of asphalt mixtures. Performance properties of CNTs modified asphalt mixtures were investigated through the Marshall stability (MS) test, indirect tensile (IDT) test, static modulus (SM) test, wheel tracking (WT) test. The results indicated that asphalt mixtures with CNT modified binder can improve both the rutting performance, IDT strength and marshall stability of tested asphalt mixtures significantly at higher percentages of carbon nanotubes. However, the issue that should be considered is the construction cost of asphalt pavement. Based on the asphalt pavement structural analysis and construction cost, it can be concluded that an optimum CNT content of 0.1% by asphalt weight may be used as additive for asphalt binder in asphalt mixtures.

Effect of Coarse Aggregate Morphology on the Resilient Modulus of Hot-Mix Asphalt

2005 ◽  
Vol 1929 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Tongyan Pan ◽  
Erol Tutumluer ◽  
Samuel H. Carpenter
Keyword(s):  
Surface Texture ◽  
Coarse Aggregate ◽  
Resilient Modulus ◽  
Asphalt Binder ◽  
Aggregate Size ◽  
Asphalt Mixtures ◽  
Maximum Aggregate Size ◽  
Asphalt Mixes ◽  
Aggregate Morphology ◽  
The Relationship

The resilient modulus measured in the indirect tensile mode according to ASTM D 4123 reflects effectively the elastic properties of asphalt mixtures under repeated load. The coarse aggregate morphology quantified by angularity and surface texture properties affects resilient modulus of asphalt mixes; however, the relationship is not yet well understood because of the lack of quantitative measurement of coarse aggregate morphology. This paper presents findings of a laboratory study aimed at investigating the effects of the material properties of the major component on the resilient modulus of asphalt mixes, with the coarse aggregate morphology considered as the principal factor. With modulus tests performed at a temperature of 25°C, using coarse aggregates with more irregular morphologies substantially improved the resilient modulus of asphalt mixtures. An imaging-based angularity index was found to be more closely related to the resilient modulus than an imaging-based surface texture index, as indicated by a higher value of the correlation coefficient. The stiffness of the asphalt binder also had a strong influence on modulus. When the resilient modulus data were grouped on the basis of binder stiffnesses, the agreement between the coarse aggregate morphology and the resilient modulus was significantly improved in each group. Although the changes in aggregate gradation did not significantly affect the relationship between the coarse aggregate morphology and the resilient modulus, decreasing the nominal maximum aggregate size from 19 mm to 9.5 mm indicated an increasing positive influence of aggregate morphology on the resilient modulus of asphalt mixes.

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