scholarly journals Physicomechanical Assessments and Heavy Metals’ Leaching Potential of Modified Asphalt Binders Incorporating Crumb Rubber and Tin Slag Powders

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Ali Huddin Ibrahim ◽  
Mohd Rosli Mohd Hasan ◽  
Ashiru Sani ◽  
Sharvin Poovaneshvaran ◽  
Tracy Leh Xin Wong ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Elastic Recovery ◽  
Asphalt Binder ◽  
Crumb Rubber ◽  
Asphalt Binders ◽  
Leaching Potential ◽  
Modified Asphalt ◽  
Industrial Solid Waste ◽  
Modified Binders ◽  
Tin Slag

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.

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.

Nonlinear Viscoelastic Response of Crumb Rubber Modified Asphalt Binder Under Large Strains

2020 ◽  
Vol 2674 (3) ◽  
pp. 139-149
Author(s):  
Saqib Gulzar ◽  
B. Shane Underwood
Keyword(s):  
Asphalt Binder ◽  
Crumb Rubber ◽  
Oscillatory Shear ◽  
Asphalt Binders ◽  
Large Strains ◽  
Viscoelastic Response ◽  
Modified Asphalt ◽  
Nonlinear Viscoelastic ◽  
Modified Asphalt Binder ◽  
Polymer Modified Asphalt

Agencies have been increasing their use of polymer modified asphalt binders in recent years to address performance issues and lengthen the useful life of their pavements. When deployed these materials likely experience strain levels exceeding their linear viscoelastic (LVE) limits. The same situation exists in non-polymer modified asphalt binders as well, but the effect may be more pronounced in polymer modified systems because of their bi-phasic nature. In this study, terminally blended crumb rubber (CR-TB) modified asphalt is studied to understand and quantify the nonlinear viscoelastic response under large strains. The CR-TB binders are extensively used in pavements subjected to high vehicular loads and extreme climatic conditions; thereby, their response under large strains becomes more critical. The current standard characterization techniques are based on LVE response using small amplitude oscillatory shear rheology only and do not consider the behavior of binders under large strains. In this study, large amplitude oscillatory shear (LAOS) rheology is used as a framework to more thoroughly investigate the complete response of the CR-TB modified asphalt binder under large strains at 30°C, 40°C, 50°C, and 60°C and at the frequencies of 0.5, 1, and 5 Hz. The LAOS response is analyzed using Fourier-transform rheology and the orthogonal stress decomposition method involving Chebyshev polynomial representation. It is found that nonlinearity manifests greatly in this study material as strain levels increase and frequencies decrease. The relative nonlinearity increases with increasing strain amplitude and is more significant towards lower end of the tested temperature range. The CR-TB binder shows strain-stiffening/softening and shear-thinning/thickening behavior depending upon a specific temperature, strain level, and frequency.

scholarly journals Preparation and Performance Analysis of High-Viscosity and Elastic Recovery Modified Asphalt Binder

2019 ◽  
Vol 2019 ◽  
pp. 1-16 ◽  
Author(s):  
Liangchen Qu ◽  
Yingli Gao ◽  
Hui Yao ◽  
Dandan Cao ◽  
Ganpeng Pei ◽  
...  
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Elastic Recovery ◽  
Asphalt Binder ◽  
Temperature Stability ◽  
Crumb Rubber ◽  
High Viscosity ◽  
High Temperature Stability ◽  
Modified Asphalt ◽  
And Performance

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.

scholarly journals Characterization of thermal storage stability of waste plastic pyrolytic char modified asphalt binders with sulfur

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0248465
Author(s):  
Abhinay Kumar ◽  
Rajan Choudhary ◽  
Ankush Kumar
Keyword(s):  
Storage Stability ◽  
Asphalt Binder ◽  
Principal Component ◽  
Thermal Storage ◽  
Asphalt Binders ◽  
Waste Plastic ◽  
Modified Asphalt ◽  
Modified Binders ◽  
Pyrolytic Char

Pyrolysis has gained a strong interest in recent times for sustainable treatment and recovery of energy-rich products from different wastes including plastic. Waste plastic pyrolytic char (PPC) generated as a carbonaceous by-product in the pyrolysis process, is gaining attention as an asphalt binder modifier. Adequate thermal storage stability is an essential requirement for a modified asphalt binder to ensure that the composite offers integrity and homogeneous properties during its storage, handling and transportation in the field. The objective of this study was to evaluate and characterize the thermal storage stability properties of PPC modified binders. PPC modified asphalt binders were fabricated and evaluated at multiple dosages of sulfur as a cross-linking agent. In addition to the conventionally used softening point difference (SPD), characterization of thermal storage stability was attempted using rheology-based separation indices (SIs) derived through temperature sweep, frequency sweep, and multiple stress creep and recovery (MSCR) tests. These rheological SIs were based on complex modulus (G*), Superpave rutting parameter (G*/sin δ), Shenoy rutting parameter (SRP), zero shear viscosity (ZSV), and MSCR Jnr (at three stress levels 0.1, 3.2 and 10 kPa). Two formulations of each rheology-based separation index were studied: (1) ratio, and (2) maximum-average difference formulations. The temperature and frequency dependencies of rheological SIs were also evaluated. Further, the Fourier transform infrared spectroscopy (FTIR) was used to characterize storage stability by comparing the chemical functionalities of the PPC modified binders. A 0.3% dosage of sulfur was found to produce the best results considering all SPD, rheology-based SIs and FTIR. Principal component analysis showed that the ratio and maximum-average formulations had similar contributions to the first principal component accounting for more than 99% of the variability.

scholarly journals Properties of Crumb Rubber and Latex Modified Asphalt Binders using Superpave Tests

2018 ◽  
Vol 203 ◽  
pp. 05007 ◽  
Author(s):  
Muslich Sutanto ◽  
Nura Bala ◽  
Kemal Al Zaro ◽  
Sri Sunarjono
Keyword(s):  
Softening Point ◽  
Asphalt Pavement ◽  
Crumb Rubber ◽  
Asphalt Binders ◽  
Rutting Resistance ◽  
Modified Asphalt ◽  
Modified Binders ◽  
Long Time ◽  
Temperature Ranges

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.

scholarly journals Balancing the Performance of Asphalt Binder Modified by Tire Rubber and Used Motor Oil

2019 ◽  
Vol 8 (4) ◽  
pp. 5501-5508
Keyword(s):  
Dominant Role ◽  
Asphalt Binder ◽  
Fatigue Cracking ◽  
Crumb Rubber ◽  
Asphalt Binders ◽  
Motor Oil ◽  
Modified Asphalt ◽  
Used Motor Oil ◽  
The Matrix ◽  
Repetitions To Failure

The crumb rubber modifier (CRM) particles release polymeric fractions in the matrix of the asphalt binder, which increase the asphalt binder’s fatigue and rutting resistance. The used motor oil (UMO) compensates the asphalt binder for the low-molecular-weight components lost during the aging processes. Moreover, UMO could increase the asphalt binder’s fluidity and softness. Therefore, modification of the asphalt binder by CRM in combination with UMO could enhance the asphalt binder’s performance. In this paper, the asphalt binder was modified by CRM. Then, the UMO was added to the crumb rubber modified asphalt (CRMA). The neat asphalt, CRMA, and UMO–CRMA binders’ resistance to rutting and fatigue cracking was evaluated. Temperature sweep test was used to evaluate the neat and modified asphalt binders’ resistance to rutting and fatigue cracking by measuring |G*|/sinδ and |G*|.sinδ parameters, respectively. Linear amplitude sweep (LAS) test was used to analyze the neat and modified asphalt binders’ resistance to fatigue cracking by measuring the number of load repetitions to failure (Nf ). It was found that using CRM and UMO enhanced the asphalt binder’s resistance to rutting and fatigue cracking. Therefore, UMO succeeded as a rejuvenator to balance the CRMA binder’s performance. This had occurred by creating a balance between the enhanced properties at high, intermediate, and low temperatures. Interaction temperature plays a dominant role in enhancing the asphalt binder’s performance: the enhancement in rutting and fatigue cracking parameters reached the highest values for CRMA or UMO–CRMA samples interacted at 190°C interaction temperature. At 220°C interaction temperature, these enhancements had decreased due to the devulcanization and depolymerization processes of the polymeric components released in the asphalt binder’s matrix.

scholarly journals Effects of Alkylamines-Based and Polyalkylene Glycol-Based Bonding Enhancers on the Performance of Asphalt Binders

2021 ◽  
Vol 920 (1) ◽  
pp. 012021
Author(s):  
H Osman ◽  
M R M Hasan ◽  
N Mukhtar ◽  
M F H M Ghazali ◽  
N A A Raman
Keyword(s):  
Elastic Recovery ◽  
Asphalt Binder ◽  
Control Sample ◽  
Asphalt Binders ◽  
Asphalt Pavements ◽  
Bituminous Materials ◽  
Polyalkylene Glycol ◽  
Modified Binders ◽  
Rotational Viscosity ◽  
Failure Temperature

Abstract The premature deterioration of asphalt pavements usually occurs due to different moisture damage mechanisms resulting in stripping, ravelling, potholes, and disintegration without proper treatment. Numerous efforts have been taken into consideration to improve the bonding between materials, hence prolonging the pavement life. This study evaluates the performance of asphalt binders incorporating Alkylamines-based (ALM) and Polyalkylene Glycol-based (PLG) bonding enhancers. Each bonding enhancer at 0.5% and 1.0% based on the weight of asphalt binder was separately blended with the conventional asphalt binder 60/70 penetration grade using a high shear mixer at 1000 rpm for 30 minutes at 160°C. The physical and rheological properties of modified binders were evaluated through penetration value, softening point, ductility, elastic recovery, rotational viscosity (RV), and dynamic shear rheometer (DSR) tests. Overall, additions of ALM and PLG show identical penetration grade compared to the control sample. Both ALM and PLG showcase a higher ductility and elastic recovery than the neat binder. The DSR test indicates the incorporation of bonding enhancers improves the modified binders’ rutting performance. While the application of ALM at 0.5% dosage increased the binder failure temperature out of all the tested samples, where the failure temperature is at 70°C, compared to others at 64°C. Studies at mastics and mixture levels should be conducted to appropriately understand the effect of bonding enhancer on the bituminous materials.

scholarly journals Mixing and Compaction Temperature of Nanosilica Composite Polymer Modified Asphalt

2020 ◽  
Vol 8 (2) ◽  
pp. 27-36
Author(s):  
Esraa J Al-mousawi ◽  
Rashaa H Al-Rubaee ◽  
Ammar A Shubber
Keyword(s):  
Surface Area ◽  
High Temperatures ◽  
Storage Stability ◽  
Asphalt Binder ◽  
Asphalt Binders ◽  
Compaction Temperature ◽  
Modified Asphalt ◽  
Modified Binders ◽  
Polymer Modified Asphalt ◽  
Waste Polypropylene

Recently, polymer -nanocomposites were used to manufacture durable asphalt mixtures to replace the polymer modified binder, because of the remarkable properties and unique features of nanomaterials compared to conventional materials, such as their wide surface area and small dimensions, making it possible to be utilized as an additive for asphalt paving. Nanosilica particles (NS) are one of the latest minerals which likely integrate useful characteristics, such as huge surface area, good distributions, high absorption levels, high stability, and a high level of purity. Therefore, this paper is interested in studying the characteristics of nanocomposite-polymer modified asphalt. In laboratory work, a pure asphalt 60-70 penetration grade, has been modified separately with waste polypropylene polymer (WPP), and nanosillica composite polypropylene (NS/WPP) at different concentrations. As a result, two modified binders: waste polypropylene polymer- modified asphalt (WPP-MA), and nanosillica composite polypropylene modified asphalt (NSCPMA) were obtained. Traditional asphalt binder tests were performed for pure and modified binders such as penetration, ductility, flash and fire point test, softening point, and rotational viscosity. Also, storage stability test has been conducted to ensure the storage stability of binders at high temperatures. The results showed an improvement in physical properties and increase in mixing and compaction temperature due to the increase in stiffness of (NSCPMA). The results also indicated that the nanosillica composite polypropylene modified asphalt binders have good storage stability at high temperatures.

scholarly journals Research of the Rheological Modification Mechanism of Crumb Rubber-Modified Asphalt Containing Polyamide 6 Additive

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Zhihua Tan ◽  
Jijing Wang
Keyword(s):  
Asphalt Binder ◽  
Interaction Mechanism ◽  
Polyamide 6 ◽  
Crumb Rubber ◽  
Asphalt Mixtures ◽  
Engineering Properties ◽  
Asphalt Binders ◽  
Modified Asphalt ◽  
The Past ◽  
Asphalt Rubber

In the past few decades, the rapid growth of automobile production in China has led to the scrapping of a large number of tires. How to dispose of tires has become a significant challenge. The addition of crushed rubber to asphalt binder not only can improve the performance of asphalt mixtures but also is an effective and environmentally friendly way to recycle scrapped tires. However, rubber asphalt mixtures demand higher production temperatures than conventional asphalt binders due to the higher viscosity of asphalt rubber binder. The main objective of this study is to evaluate the rheological properties of rubber-modified asphalt by adding polyamide 6 and investigate the modification mechanism of crumb rubber-modified asphalt (CRMA) after adding polyamide 6. To this end, the content of waste rubber in the prepared rubber asphalt was 20%. The conventional laboratory rheological tests were employed to evaluate the performance of crumb rubber-modified asphalt after adding polyamide 6. Furthermore, to investigate the interaction mechanism of crumb rubber and asphalt, a series of advanced tools, including the scanning electron microscopy (SEM) test, differential scanning calorimeter (DSC) test, and Fourier transform infrared spectroscopy (FTIR) test, were conducted. From the experimental results obtained, it may be concluded that crumb rubber-modified asphalt with adding polyamide 6 not only improves the engineering properties of the rubber-modified asphalt but also improves the performance of rubber asphalt. From the FTIR and SEM tests, it is concluded that there is no new functional group in the mixing process of crumb rubber and the asphalt, which contributes to the storage stability of asphalt binder and runway.

Applicability of Superpave Binder Testing Protocols to Modified Binders

1997 ◽  
Vol 1586 (1) ◽  
pp. 16-23 ◽  
Author(s):  
Hussain U. Bahia ◽  
Dario Perdomo ◽  
Pamela Turner
Keyword(s):  
Elastic Recovery ◽  
Crumb Rubber ◽  
Test Methods ◽  
Rate Dependency ◽  
Modified Asphalt ◽  
Modified Binders ◽  
Modified Binder ◽  
Physical And Chemical ◽  
Departments Of Transportation ◽  
Testing Protocols

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.

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