Study on properties of recycled tire rubber modified asphalt mixtures using dry process

2007 ◽  
Vol 21 (5) ◽  
pp. 1011-1015 ◽  
Author(s):  
Weidong Cao
Keyword(s):  
Asphalt Mixtures ◽  
Tire Rubber ◽  
Dry Process ◽  
Modified Asphalt

Laboratory and Field Evaluation of Pre-Treated Dry-Process Rubber-Modified Asphalt Binders and Dense-Graded Mixtures

2021 ◽  
pp. 036119812110114
Author(s):  
Punyaslok Rath ◽  
Hamed Majidifard ◽  
Behnam Jahangiri ◽  
Shishi Chen ◽  
William G. Buttlar
Keyword(s):  
Field Performance ◽  
Field Evaluation ◽  
Asphalt Mixtures ◽  
Asphalt Binders ◽  
Tire Rubber ◽  
Ground Tire Rubber ◽  
Dry Process ◽  
Modified Asphalt ◽  
Rubber Particles ◽  
Flexibility Index

Pre-treatment of ground tire rubber is emerging as a popular method to incorporate rubber particles in dense-graded asphalt mixtures. This study investigates the effects of a chemically engineered Dry-Process Ground Tire Rubber (DP-GTR) modification in asphalt binders and mixtures. The DP-GTR is comprised of rubber particles measuring 400 to 600 µm in diameter (minus #30 mesh) coated with a non-elastomeric liquid. No change in aggregate gradation is necessary in DP-GTR modification of asphalt mixtures. In this study, the effects of DP-GTR modification on binder properties were measured by dynamic shear rheometer, Multiple Stress Creep and Recovery (MSCR), and bending beam rheometer tests. Additionally, mixture properties measured by three cracking tests: Disk-shaped Compact Tension (DC[T]) test, Illinois Flexibility Index, and indirect tensile asphalt cracking test and one rutting test (Hamburg wheel track test) were evaluated. Results showed: (a) 10–12°C bump on binder high temperature performance grade with 10% DP-GTR modification by weight of binder; (b) improvement in non-recoverable compliance in MSCR test indicated higher rut resistance; (c) increase in DC(T) fracture energy at low temperatures; (d) decrease in rut depth; and (e) decrease in flexibility index and cracking test index. Field performance of the chemically treated DP-GTR sections located in different states was examined to address discrepancies observed in the cracking tests. The cracking and rutting performance of all the field sections was good-to-excellent, suggesting that some of the currently popular simple cracking tests may not be able to properly assess the cracking resistance inherent in GTR-modified asphalt mixtures.

Recycled Polyethylene Modified Asphalt Binders and Mixtures: Performance Characteristics and Environmental Impact

2022 ◽  
pp. 036119812110657
Author(s):  
Ibrahim A. Abdalfattah ◽  
Walaa S. Mogawer ◽  
Kevin D. Stuart
Keyword(s):  
Asphalt Binder ◽  
Asphalt Mixture ◽  
Asphalt Mixtures ◽  
Asphalt Binders ◽  
Dry Process ◽  
Modified Asphalt ◽  
Wet Process ◽  
Melted Snow ◽  
Recycled Polyethylene ◽  
Asphalt Paving

This study addresses the effects of recycled polyethylene (RPE) on the performances of both asphalt binders and asphalt mixtures. Whether using RPE in an asphalt mixture might leach harmful chemicals into rainwater or melted snow was also determined. Two processes, wet and dry, were used to formulate the RPE modified asphalt binders and mixtures. In the wet process, RPE was added to asphalt binder. In the dry process, it was added to heated aggregates. RPE from two sources and PG 64-22 virgin asphalt binders from two sources were used in this study. In conclusion, RPE improved the rutting resistance of the asphalt binders and asphalt mixtures. However, it had adverse effects on their resistance to intermediate-temperature and non-load associated cracking. The dry process could produce a mixture with a higher RPE dosage compared with the wet process using one virgin asphalt binder but not the other; thus, the virgin asphalt binder source was a significant factor for the dry process. Based on an embryotoxicity test, it was found that RPE can be used by the asphalt paving industry without creating any significant environmental risks.

scholarly journals Performance Analysis of Asphalt Mixtures Modified with Ground Tire Rubber Modifiers and Recycled Materials

2019 ◽  
Vol 11 (6) ◽  
pp. 1792 ◽  
Author(s):  
Punyaslok Rath ◽  
Joshua Love ◽  
William Buttlar ◽  
Henrique Reis
Keyword(s):  
Compact Tension ◽  
Asphalt Mixtures ◽  
Asphalt Pavements ◽  
Tire Rubber ◽  
Ground Tire Rubber ◽  
Reclaimed Asphalt ◽  
Dry Process ◽  
Polymer Hybrid ◽  
And Performance ◽  
Wheel Tracking

The usage of Ground Tire Rubber (GTR) in asphalt pavements has gained renewed interest due to its potential sustainability, economic, and performance benefits. This study focuses on asphalt mixtures designed with three different rubber modifier products including (1) a terminal-blend GTR, (2) a dry-process, chemically processed rubber product, and (3) a terminal-blend rubber-polymer hybrid product. The modifications were incorporated into Illinois Tollway’s approved Stone Matrix Asphalt (SMA) designs using (1) a base binder (PG 58-28), (2) a softer binder (PG 46-34), and (3) a softer binder with higher recycled content. Disk-shaped Compact Tension (DC(T)) test, Hamburg Wheel Tracking Test (HWTT) and Acoustic Emission (AE) tests were performed to characterize the mixtures. The fracture energy for most mixtures met the stringent criteria of 690 J/m2 and the rut depths measured were less than 6 mm at 20,000 wheel passes. A Hamburg-DC(T) plot suggests that higher amounts of RAP/RAS (RAP: Reclaimed Asphalt Pavement; RAS: Reusable Asphalt Shingles) can be successfully used if a suitably soft base binder is employed.

scholarly journals A review of the best experience on crumb rubber – dry process modified asphalt mixture performance

2021 ◽  
Author(s):  
Ovidijus Šernas ◽  
Audrius Vaitkus ◽  
Deimantė Kilaitė
Keyword(s):  
Asphalt Mixture ◽  
Crumb Rubber ◽  
Asphalt Mixtures ◽  
Waste Products ◽  
Dry Process ◽  
Modified Asphalt ◽  
Wet Process ◽  
Water Sensitivity ◽  
Modification Process ◽  
Dry Modification

The use of crumb rubber made from end of life tyres for asphalt mixtures modification in order to improve their properties or just utilize waste products may be considered as potential solution. Crumb rubber can be used as a bitumen modifier (wet process) or supplementary component of the asphalt mixture (dry process). Dry modification process has more potential due relatively unsophisticated technology and higher possible to use amount of crumb rubber comparing to the wet process. The performance of asphalt mixtures modified by dry process mainly depends on several factors as crumb rubber type, content and size. However, limited number of publications reported the results of dry method crumb rubber modified asphalt mixtures performance. This paper summarizes the latest findings from literature review on the modification technologies and specifications related to dry modification process, the effect of crumb rubber type and amount on modified asphalt mixture performance in terms of stiffness, rutting resistance, water sensitivity, resistance to fatigue and low temperature cracking. The algorithm of crumb rubber modified asphalt mix design was introduced.

Evaluation of Cracking Resistance of Tire Rubber–Modified Asphalt Mixtures

2021 ◽  
Vol 147 (3) ◽  
pp. 04021019
Author(s):  
Christopher A. T. Castillo ◽  
Adam J. Hand ◽  
Peter E. Sebaaly ◽  
Elie Y. Hajj ◽  
Murugaiyah Piratheepan
Keyword(s):  
Asphalt Mixtures ◽  
Cracking Resistance ◽  
Tire Rubber ◽  
Modified Asphalt

Effect of Addition of Dry Crumb Rubber on the Performance of Terminal Blend Crumb Rubber Modified Asphalt Mixtures

2017 ◽  
Vol 2633 (1) ◽  
pp. 90-97 ◽  
Author(s):  
Salih Kocak ◽  
M. Emin Kutay
Keyword(s):  
Asphalt Binder ◽  
Asphalt Mixture ◽  
Crumb Rubber ◽  
Asphalt Mixtures ◽  
Fine Aggregate ◽  
Dry Process ◽  
Modified Asphalt ◽  
Wet Process ◽  
Low Temperature Cracking ◽  
Linear Viscoelastic

Three major methods are used to produce crumb rubber modified asphalt pavement: the dry process (CRDry), the terminal blend process (CRTB), and the wet process (CRWet). Although the CRDry process replaces the portion of fine aggregate in the asphalt mixture with crumb rubber (CR) particles, the CRWet process incorporates CR particles into hot liquid asphalt before it is mixed with aggregates. CRTB is known as a special type of CRWet process in which the CR is blended with asphalt binder at the asphalt terminal. In general, the CRWet process can integrate 15% to 22% CR by weight of the binder. This amount ranges from 10% to 12% in the CRTB process as a result of the limitations associated with transportation and pumping. This study investigated the feasibility of increasing the CR content of CRTB modified asphalt mixtures. The addition to the mixture of about 0.5% CR (by weight of the mix) through the CRDry process doubled the amount of rubber to be found in a conventional CRTB mix. The relative performances of the CRTB and the CRTB+CRDry processes [i.e., crumb rubber hybrid (CRHY)] were investigated with respect to their linear viscoelastic properties, rutting susceptibility, moisture damage, resistance to fatigue, and low temperature cracking. It was shown that it was possible to increase the amount of CR in the mixture through the use of the CRHY method proposed here, without adverse effect on the performance of the mixture.

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