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 Balancing the Performance and Environmental Concerns of Used Motor Oil as Rejuvenator in Asphalt Mixes

Recycling ◽  
2019 ◽  
Vol 4 (1) ◽  
pp. 11 ◽  
Author(s):  
Eslam Deef-Allah ◽  
Magdy Abdelrahman ◽  
Mark Fitch ◽  
Mohyeldin Ragab ◽  
Mousumi Bose ◽  
...  
Keyword(s):  
Environmental Protection Agency ◽  
Asphalt Binder ◽  
Crumb Rubber ◽  
Asphalt Binders ◽  
Environmental Concerns ◽  
Ethyl Benzene ◽  
Motor Oil ◽  
Asphalt Mixes ◽  
Used Motor Oil ◽  
The Us

Road deterioration inspires researchers to enhance the properties of asphalt binder for better performing mixes. Recycled tire rubber, or crumb rubber modifier (CRM), and used motor oil (UMO) are two modifiers that enhance asphalt binder performance through two different mechanisms. CRM affects high-temperature properties while UMO modifies low-temperature properties. Potential environmental concerns arising from the use of UMO have been raised in the literature. In this paper, the two recycled materials were investigated for their ability to complement each other. Both performance benefits of using both materials and the environmental concerns of using UMO were studied. Four CRM asphalt binders were investigated: two with UMO and two without UMO. Environmental impacts were evaluated using gas chromatography to check air emissions for benzene, toluene, ethyl-benzene, and xylenes (BTEX). The potential for toxic leaching of elements from modified hot mix asphalt (HMA) were checked using the US Environmental Protection Agency (EPA) Toxicity Characteristic Leaching Protocol (TCLP). For asphalt binders modified by CRM-UMO combinations, CRM decreased the amounts of released BTEX components, presumably by absorbing UMO and slowing the release of BTEX. Leaching results concluded that UMO mixtures showed a notable percentage of sulfur (S) as compared to non-UMO mixes. All these leachate components were under EPA limits.

Laboratory Assessment of Workability of Asphalt Rubber Hot Mixes Using Warm Mix Technology

2012 ◽  
Vol 193-194 ◽  
pp. 452-457 ◽  
Author(s):  
Meng Yun Huang ◽  
Jing Hui Liu ◽  
Xi Zhang ◽  
Dan Ni Li
Keyword(s):  
Asphalt Binder ◽  
Asphalt Mixture ◽  
Crumb Rubber ◽  
Laboratory Assessment ◽  
Asphalt Mixes ◽  
Modified Asphalt ◽  
The Road ◽  
Asphalt Rubber ◽  
Synergy Effects ◽  
Save Energy

Using the waste crumb rubber modified asphalt to pave the road surface could reduce cost and save energy. However，in order to obtain adequate workability, the mixing temperature and compaction temperature of rubberized asphalt binder and its mixture is much higher than those of conventional asphalt mixtures. Warm Mix Asphalt (WMA) is the name given to certain technologies that reduce the production and placement temperatures of asphalt mixes. One of the main benefits advertised is the increased workability at conventional and lower compaction temperatures with the WMA addition. This paper evaluates whether there are any synergy effects of using warm mix technologies and Asphalt Rubber(AR) hot mixes. This paper summarizes a lab research to evaluate the workability of Asphalt Rubber hot mixes containing warm mix technologies. Both asphalt binder and asphalt mixture were evaluated and compared. The research suggests that combining WMA technology with Asphalt Rubber mixtures is a win-win.

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 Investigation on Preparation Process and Storage Stability of Modified Asphalt Binder by Grafting Activated Crumb Rubber

Materials ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 2014 ◽  
Author(s):  
Juan Xie ◽  
Yueming Yang ◽  
Songtao Lv ◽  
Xinghai Peng ◽  
Yongning Zhang
Keyword(s):  
Softening Point ◽  
Molecular Design ◽  
Asphalt Binder ◽  
Crumb Rubber ◽  
Preparation Process ◽  
Range Analysis ◽  
Rubber Content ◽  
Segregation Index ◽  
Modified Asphalt ◽  
Modified Asphalt Binder

According to the theory of molecular design, crumb rubber was grafting activated with acrylamide and then used as asphalt binder modifier. An orthogonal three-factor, three-level test was designed to optimize the preparation process of modified asphalt. Softening point, viscosity, rutting factor, ductility, stiffness modulus and creep speed index were selected as evaluation indicators to study the effects of rubber content, shear time and shear temperature by variance analysis and range analysis. The results show that the rubber content had a significant impact on the performance of modified asphalt with grafting-activated crumb rubber, while the shear temperature and shear time had little effect. The grafting activated crumb rubber content of 20%, shear temperature of 170–190 °C, and shear time of 90 min was determined as the reasonable preparation process. Modified asphalt with common crumb rubber (CRMA) and modified asphalt with grafting activated crumb rubber (A-G-R) were prepared, respectively, using the reasonable process to analyze the influence of grafting activation of crumb rubber. The results indicate that A-G-R had smaller softening point difference, lower segregation index and more stable and uniform dispersed phase.

scholarly journals Evaluation of Rutting and Fatigue Behaviors of Asphalt Binders Modified with Calcium Lignosulfonate

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Saeed Fatemi ◽  
Jafar Bolouri Bazaz ◽  
Seyed Ali Ziaee
Keyword(s):  
Storage Stability ◽  
Asphalt Binder ◽  
Thermal Storage ◽  
Fatigue Performance ◽  
Stability Test ◽  
Asphalt Binders ◽  
Test Results ◽  
Asphalt Mixes ◽  
Modified Asphalt ◽  
The Impact

Asphalt mixes encounter different distress during the life cycle of asphalt pavements, among which rutting and fatigue failure are prominent. Moreover, the addition of environmentally friendly modifiers into the asphalt binder to increase the performance of asphalt mixes has been a challenging phenomenon for researchers. Calcium lignosulfonate (CL) is a waste material that is a by-product of the wood industry. In this paper, the impact of the calcium lignosulfonate on the rutting and fatigue performance of the asphalt binder was investigated. For this purpose, the Dynamic Shear Rheometer (DSR) was utilized to run the Multiple Stress Creep Recovery (MSCR) test and evaluate G ∗ /sinδ and G ∗ ·sinδ indices for the asphalt binder containing different percentages of CL. The elastic recovery test was also conducted on the asphalt binder. In order to analyze the thermal storage stability of CL-modified asphalt binders, the storage stability test was considered. The Field Emission Scanning Electron Microscope test showed that using CL as a binder modifier makes the texture of the asphalt binder spongy and porous. The conventional test results indicated that increasing the CL amount in the asphalt binder led to an increase in the stiffness of the asphalt binder. The rheological test results showed that the rutting resistance of the asphalt binder improved by adding up to 15% of the CL powder; however, the fatigue performance and the elasticity of the asphalt binder declined by increasing the CL content in the asphalt binder. The storage stability test revealed that the dispersion of CL in the asphalt binder was uniform; moreover, the presence of CL in the asphalt binder could not adversely affect the thermal storage stability of the modified asphalt binder.

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 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 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.

Experimental Research on Crumb Rubber and Polyphosphoric Acid Composite Modified Asphalt Binders

2012 ◽  
Vol 174-177 ◽  
pp. 1579-1583 ◽  
Author(s):  
Wei Dong Cao
Keyword(s):  
Polyphosphoric Acid ◽  
Asphalt Binder ◽  
Crumb Rubber ◽  
Orthogonal Test ◽  
Asphalt Binders ◽  
Experimental Program ◽  
Test Design ◽  
Particle Sizes ◽  
Modified Asphalt ◽  
Orthogonal Test Design

In order to research the properties of crumb rubber (CR) and polyphosphoric acid (PPA) composite modified asphalt binders, an orthogonal test design is employed to arrange the experimental program. Three particle sizes of CR, three contents of CR and PPA were representatively selected as three influencing factors and levels. A total of nine composite modified asphalt binders were produced in laboratory and the conventional penetration grading indexes including penetration, softening point and ductility were conduced. The results indicate that the properties of composite modified asphalt binders are improved not only at high temperatures but also at low temperatures compared to the base asphalt binder. Based on variance analysis, the optimal proportion of CR and PPA composite modified asphalt is recommended.

scholarly journals Mechanical Characteristics of Graphene Nanoplatelets-Modified Asphalt Mixes: A Comparison with Polymer- and Not-Modified Asphalt Mixes

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2434
Author(s):  
Laura Moretti ◽  
Nico Fabrizi ◽  
Nicola Fiore ◽  
Antonio D’Andrea
Keyword(s):  
Fatigue Resistance ◽  
Graphene Nanoplatelets ◽  
Asphalt Mixtures ◽  
Asphalt Binders ◽  
Asphalt Mixes ◽  
Modified Asphalt ◽  
Bituminous Mixtures ◽  
Water Sensitivity ◽  
Polymer Modified Asphalt ◽  
Mechanical Performances

In recent years, nanotechnology has sparked an interest in nanomodification of bituminous materials to increase the viscosity of asphalt binders and improves the rutting and fatigue resistance of asphalt mixtures. This paper presents the experimental results of laboratory tests on bituminous mixtures laid on a 1052 m-long test section built in Rome, Italy. Four asphalt mixtures for wearing and binder layer were considered: two polymer modified asphalt concretes (the former modified with the additive Superplast and the latter modified with styrene–butadiene–styrene), a “hard” graphene nanoplatelets (GNPs) modified asphalt concrete and a not-modified mixture. The indirect tensile strength, water sensitivity, stiffness modulus, and fatigue resistance of the mixtures were tested and compared. A statistical analysis based on the results has shown that the mixtures with GNPs have higher mechanical performances than the others: GNP could significantly improve the tested mechanical performances; further studies will be carried out to investigate its effect on rutting and skid resistance.

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