Applicability of Superpave Binder Testing Protocols to Modified Binders

Author(s):  
Hussain U. Bahia ◽  
Dario Perdomo ◽  
Pamela Turner

An effort is made to summarize current practices for modifying paving asphalts. The types and classes of modifiers used, or considered, for paving applications are reviewed. The applicability of the Superpave binder specification (AASHTO MP1) is reviewed critically, and the modified-asphalt characteristics that are not considered in this specification are evaluated. Conventional testing results of modified binders are compared with Superpave testing results. The results indicate that a variety of additives can be classified, on the basis of their composition and their effects on asphalts, as polymers (elastomeric and plastomeric), fillers, fibers, hydrocarbons, antistripping agents, oxidants, antioxidants, crumb rubber, and extenders. These additives vary significantly in their physical and chemical characteristics and are expected to have widely variable effects on performance-related properties of asphalts. The assumptions supporting the criteria in the Superpave binder specification may not be valid for some modified binder systems. Furthermore, the testing protocols included in the specification do not consider certain important characteristics that are typical of particular modified binders. Among these characteristics are strain dependency, thixotropy, loading-rate dependency, and time-temperature equivalency. Conventional measurements used currently by state departments of transportation such as ductility, elastic recovery, and resilience, were collected. The ranking of five modified systems on the basis of conventional and Superpave measurements was analyzed. The analysis does not indicate that the conventional test methods are consistent in their rankings, nor does it indicate that these measures add much to the information deduced from the Superpave data.

2012 ◽  
Vol 256-259 ◽  
pp. 1837-1844 ◽  
Author(s):  
Iman Mohammadi ◽  
Hadi Khabbaz

The use of modified asphalt binders has become much more common over the past two decades. Many types of modifier have been used in paving asphalts to enhance the performance of asphalt pavements in a wide range of climates and loading conditions. Among various asphalts binder modifiers, the recycled crumb rubber has been used very successfully for many years. Generally in production of CRM binder, mixing and compaction temperature is determined by measuring of binder viscosity. The ordinary method used for viscosity measurement of unmodified binder leads to a very high Mixing and Compaction Temperature (MCT) for CRM binder. The aims of this paper are to identify, develop and give some recommendations on a reliable laboratory approach for blending of CRM with binder, as well as introducing appropriate laboratory test methods for optimisation of MCT of crumb rubber modified binder asphalt.


Author(s):  
Hussain U. Bahia ◽  
Huachun Zhai ◽  
Andres Rangel

In a recent survey of users and producers of modified asphalts, stability and short-term aging were two of the main concerns regarding the use of modified asphalts. In an NCHRP project, a concentrated effort was put into development of revised or new testing procedures to better characterize the nature of modified asphalt and to solve some of the difficulties with using existing aging procedures developed for neat asphalts and modified asphalts. Three main procedures have been proposed to complement the existing Superpave procedures: the laboratory asphalt stability test, for measuring the storage stability of asphalt binders; the particulate additive test, for separation of particulate additives; and the modified rolling thin film oven test for short-term aging. The background behind the development of these test methods is explained, and typical data collected for a number of modified asphalts are presented. The results indicate that these tests show high promise in covering characteristics not covered by the current Superpave binder specifications and in solving some of the problems with the existing aging methods. The results also indicate that the behavior of modified binder can be very complex and that the method of data interpretation is very critical.


2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Ali Huddin Ibrahim ◽  
Mohd Rosli Mohd Hasan ◽  
Ashiru Sani ◽  
Sharvin Poovaneshvaran ◽  
Tracy Leh Xin Wong ◽  
...  

Industrial solid waste has been widely used as an alternative additive for bituminous material modification. This study aims to evaluate the basic properties and quantify the leaching potential of modified asphalt binders incorporating crumb rubber powder (CRP) from waste tires and tin slag (TS) for a local smelting company. Three percentages of CRP and TS, at 5, 10, and 15%, were considered. The conventional asphalt binder (PEN 60/70), CRP, and TS-based modified asphalt binders were analyzed for toxicity, softening point, penetration value, elastic recovery, torsional recovery (TR), and coatability index. The findings indicated that the addition of the waste materials led to no significant heavy metal content in the asphalt binder mix. Moreover, the basic and physical properties of the asphalt binders were also improved by 5, 10, and 15% of the waste, respectively. However, TS waste exhibited limited effects on all the parameters and had a 5% optimum dosage. The modified binders’ results showed that the CRP modified asphalt binders had fewer heavy metals and responded more to elastic recovery and coatability.


2019 ◽  
Vol 271 ◽  
pp. 03008
Author(s):  
MM Tariq Morshed ◽  
Mohammad Nazmul Hassan ◽  
Zahid Hossain

For characterizing the polymer modified binders, different state Departments of Transportation (DOTs) use different time consuming and empirical Performance Grade (PG) Plus test methods. Furthermore, the PG Plus tests are silent when asphalt binders are modified with chemicals such as polyphosphoric acid (PPA). But, the effects of the polymer are not accurately identified through these conventional tests such as Elastic Recovery (ER) and tenacity. The main goal of this study is to recommend alternative test method(s), which can possibly be pursued by using, a Dynamic Shear Rheometer (DSR). Thus, Multiple Stress Creep and Recovery (MSCR), ER-DSR, Frequency Sweep, and Binder Yield Energy Test (BYET) are being explored to find their effectiveness. Three PG binders (PG 64-22, PG 70-22 and PG 76-22) have been selected for this investigation. These binders have been prepared with styrene-butadiene-styrene (SBS) polymer, PPA, or a combination of both. Further, chemical tests such as SARA (Saturate, Aromatic, Resin, and Asphaltene) analysis and FTIR (Fourier-transform Infrared spectroscopy) are also being explored to fulfill the objectives. Preliminary findings suggest that the PG Plus tests deem to be obsolete. Also, a single test procedure is not sufficient to identify the presence and effectiveness of modifiers in the PG binders.


2019 ◽  
Vol 2019 ◽  
pp. 1-16 ◽  
Author(s):  
Liangchen Qu ◽  
Yingli Gao ◽  
Hui Yao ◽  
Dandan Cao ◽  
Ganpeng Pei ◽  
...  

This study presented the preparation and performance of a kind of high viscosity and elastic recovery asphalt (HVERA) by using some modifiers. The performance of styrene-butadiene-styrene (SBS), rock asphalt (RA), crumb rubber (CR), and stabilizing agent (SA) for different modifiers was investigated by conventional binder test. Effects of modifiers on the high- and low-temperature properties of HVERA were investigated. The dynamic viscosity (DV) test, dynamic shear rheometer (DSR), and bending beam rheometer (BBR) analysis indicated that the high- and low-temperature rheological properties of asphalt were improved attribute to the addition of mixture of modifiers. Meanwhile, the short-term aging and long-term aging were simulated by rolling thin film oven (RTFO) and pressure aging vessel (PAV) tests. Furthermore, the Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM) measurements were conducted for obtaining the mechanism and microstructure distribution of the modified asphalt binders. From the test results in this study, it was evident that the addition of SBS, RA, CR, and SA into a neat asphalt binder could both significantly improve the viscosity of the binder at high temperature and lower the creep stiffness at low temperature, which was beneficial to better both high-temperature stability and low-temperature cracking resistance of asphalt pavements. It was proved that the high temperature grade of HVERA could be increased by increasing of RA and a proper percentage of modifiers could be improved by the low temperature grade of HVERA.


Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2693
Author(s):  
Weihong Liu ◽  
Yishen Xu ◽  
Hongjun Wang ◽  
Benan Shu ◽  
Diego Maria Barbieri ◽  
...  

Segregation of waste crumb rubber powder (WR) modified asphalt binders the large-scale application of WR in asphalt. The method of microwave activation combined with chemical activation (KMWR) was proposed to improve storage stability and rheological properties of WR modified asphalt in this work. Storage stability and rheological properties of virgin asphalt, MWR modified asphalt, and KMWR modified asphalt were comparatively studied by the standard segregation test, bending beam rheometer (BBR) test, and dynamic shear rheometer (DSR) test. The effect of composite activation on waste rubber powder particles was studied by Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), and Brunauer–Emmett–Teller (BET) tests. The main results showed that after the physical and chemical composite activation, the storage stability of waste rubber powder modified asphalt was significantly improved, WR modified asphalt had better crack resistance, better rutting resistance, and better fatigue performance. After physical and chemical activation, WR was desulfurized, and a large number of active groups was grafted on the WR particles.


2018 ◽  
Vol 203 ◽  
pp. 05007 ◽  
Author(s):  
Muslich Sutanto ◽  
Nura Bala ◽  
Kemal Al Zaro ◽  
Sri Sunarjono

Polymer modified binders have been used for long time to improve the quality of asphalt pavement. This study investigates the effect of crumb rubber and latex on the properties of bitumen binders. Crumb rubber and latex were added to the control 60/70 pen grade bitumen. Four different proportions of crumb rubber and latex were considered in this study: 0%, 4%, 6% and 8% by weight of bitumen binder. The effect of crumb rubber and latex were evaluated through standard penetration and softening point tests as well as dynamic shear rheometer (DSR) test. Temperature ranges of 20°C - 40°C were used for the DSR rheological testing. The results showed that the addition of crumb rubber and latex leads to a promising improvement on the binder properties. A reduction in penetration and an increase in softening point temperature were observed with the addition of either crumb rubber or latex, this indicates improvement in stiffness and rutting resistance. The analysis on DSR results also show that the modified binders have good rutting resistance.


2018 ◽  
Vol 250 ◽  
pp. 02008 ◽  
Author(s):  
Mohammad Nasir Mohammad Taher ◽  
Mohamad Yusri Aman ◽  
Nor Farah Azila Abdullah@Musa

Modification of asphalt to improve the overall performance of pavements has been the focus of numerous researchers in recent years. This paper discovered whether the use of chemical additives namely Advera® is possible to influence the physical and chemical bonding of asphalt binder grade 80/100 subjected to different aging conditions. The fundamental characteristics of modified binder containing 4%, 5%, 6% and 7% of Advera® were determined by conventional methods while chemical characterisation was assessed by conducting Fourier tTransform iInfrared sSpectroscopy (FTIR). With the aid of image tool, scanning electron microscopy (SEM) was employed to study the surface texture and morphology of Advera® modified binder.The results indicated that, the Advera® modified binder had improved the physical and chemical properties over base binder for both aging condition. The SEM images show that the microstructure of Advera® modified asphalt binder changed compared to the control asphalt binder. A good dispersion of Advera® particles in the asphalt binder matrix is observed. This is proved by the FTIR results which indicate that the stretching of hydroxide is increase when the Advera® is added in the virgin asphalt binder.


2019 ◽  
Vol 9 (1) ◽  
pp. 3765-3769
Author(s):  
K. Jadidi ◽  
M. Khalili ◽  
M. Karakouzian ◽  
S. Amirkhanian

The toughness and tenacity test method, which was developed in the 1980s, is popular for evaluating a polymer-modified binder. Several states like Nevada require performing this test to evaluate non-modified binder samples, as well as other types of modified binders. In this regard, a toughness and tenacity test was performed on rubber-modified samples produced from virgin binder PG58-28, PG64-16 and AC-20. In order to take the rubber size, type and content into account, two rubber sizes, mesh #20 and #40, two rubber types, ambient and cryogenic, and three rubber contents, 10%, 15%, and 20% were produced and tested. The results then were compared with polymer-modified and terminally blended rubber-modified samples. The results show improvement in the amount of initial maximum strength, and a decline in the magnitude of elongation, toughness and tenacity for the rubber-modified binder, compared to other types of binders.


Author(s):  
Robert Y. Liang ◽  
Suckhong Lee

Aging of asphalt has been an important subject area that has received extensive studies in recent years. Test results of short-term and long-term aging behavior of crumb rubber modifier (CRM) modified asphalt paving materials are presented. Eighteen combinations of CRM modified binders in terms of CRM size, CRM content, and base asphalt cement grade were studied by Brookfield viscometer test and dynamic shear rheometer test. The short-term aged binders were prepared using thin film oven test. Viscosity was measured at 350°F in the Brookfield thermosel after mixing at 375°F for 2 hr. The test results showed that the size and percentage of CRM affected the viscosity development in the modified binders: the smaller the CRM size and the higher the CRM content, the higher the viscosity measured after 2-hr reaction at 375°F. Short-term aging exerted more viscosity increase in the CRM modified binders than in the unmodified binders. Modified binders showed less weight loss than unmodified binders. The modified binders showed higher complex modulus G* than unmodified. Short-term aging increased G*, with modified binders exhibiting higher increase. The Marshall mix design yielded various CRM modified mixes. The result of indirect tensile strength tests showed that short-term and long-term aging increased the measured tensile strengths. The resilient modulus test results, in general, supported the general understanding that aging tended to increase resilient modulus.


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