Evaluation on Mix Design and Rutting Resistance of Dry Mixed Rubberised Asphalt Mixtures

This study presents a laboratory evaluation on the properties of crumb rubber modified asphalt mixture using a dry process method in which the fine crumb rubber is added to substitute the aggregates portion and acts as elastic aggregates within the mix. The effect of crumb rubber in the mixture was investigated in terms of the volumetric properties using Marshall Mix Design and rutting performance using Wheel Tracking Test. The crumb rubber was added between 1 to 3% in steps of 1% by weight of aggregates to modify a dense graded mix, Asphaltic Concrete (AC14) and a gap graded mix, Stone Mastic Asphalt (SMA14) according to the Malaysian mix design. Based on the result, it was observed that the performance of the asphalt mixtures was significantly affected with the addition of crumb rubber. Rubberised asphalt mixtures for AC14 were found to have a greater resistance on rutting deformation compared to the conventional mixture. However, the use of fine rubber in SMA14 mixture with 80/100 bitumen cannot provide enough binder modification to perform as good as conventional SMA14 mixture with polymer modified bitumen. Furthermore, based on detailed review, a set of procedures for producing dry mixed rubberised asphalt mixture was identified and recommended for future studies.

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Functional and environmental performance of plant-produced crumb rubber asphalt mixtures using the dry process

Materials and Structures ◽

10.1617/s11527-021-01790-y ◽

2021 ◽

Vol 54 (5) ◽

Author(s):

M. Bueno ◽

R. Haag ◽

N. Heeb ◽

P. Mikhailenko ◽

L. Boesiger ◽

...

Keyword(s):

Environmental Performance ◽

High Performance ◽

Large Scale ◽

Fatigue Behavior ◽

Permanent Deformation ◽

Asphalt Mixture ◽

Crumb Rubber ◽

Asphalt Mixtures ◽

Gaseous Emissions ◽

Dry Process

AbstractIncorporating crumb rubber (CR) using the dry process, directly in the asphalt mixture rather than into the bituminous binder requires no plant retrofitting, and therefore is the most practical industrial method for CR incorporation into asphalt mixtures. Nevertheless, very few large scale studies have been conducted. This work uses a holistic approach and reports on the functional and environmental performance of asphalt mixtures with different concentrations of CR fabricated employing the dry process in asphalt plants. Gaseous emissions were monitored during the production and laboratory leaching tests simulating the release of pollutants during rain, was conducted to evaluate the toxicology of both the CR material alone and the modified asphalt mixtures. In addition, laboratory compacted samples were tested to assess their fatigue behavior. Furthermore, noise relevant surface properties of large roller compacted slabs were evaluated before and after being subjected to a load simulator (MMLS3) to evaluate their resistance to permanent deformation. The results confirm that comparable performance can be achieved with the incorporation of CR using the dry process for high performance surfaces such as semi-dense asphalt, which usually require the use of polymer modified binders. Environmental performance improvement can be achieved by a washing step of the CR material that could remove polar CR additives which have commonly been used as vulcanization accelerator during rubber production.

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Pavement Performance of Hot In-Place Recycling for Waste Asphalt Mixtures

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.668.292 ◽

2013 ◽

Vol 668 ◽

pp. 292-296

Author(s):

Ya Li Ye ◽

Chuan Yi Zhuang ◽

Jia Bo Hu

Keyword(s):

Asphalt Mixture ◽

Asphalt Mixtures ◽

Asphalt Pavements ◽

Pavement Performance ◽

Test Results ◽

Technical Parameters ◽

Stable Performance ◽

Wheel Tracking Test ◽

Asphalt Content ◽

Wheel Tracking

With the early asphalt pavements have been into the stage of medium maintenance or overhaul, recycling is a very important way for waste asphalt mixtures. A sample was taken in the expressway from Huhhot to Baotou, and the waste mixtures were extracted from field and sieved; so that the new aggregates can be determined and mix design was carried. With the aid of the penetration, the softening point and the viscosity in 135°C test, the quantity of the regenerant and the asphalt content were ascertained. Through the high temperature stable performance, the anti-low temperature performance, the water stability and the Hamburg wheel-tracking test, the appropriate gradation and the optimum asphalt content were determined. The test results showed that the pavement performance of the waste asphalt mixture was enhanced obviously with hot in-place recycling, and it has achieved technical parameters for old asphalt mixture.

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

10.5592/co/cetra.2020.1323 ◽

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.

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

Transportation Research Record Journal of the Transportation Research Board ◽

10.3141/2633-11 ◽

2017 ◽

Vol 2633 (1) ◽

pp. 90-97 ◽

Cited By ~ 3

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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Effect of Addition of Rubber Granulate and Type of Modified Binder on the Viscoelastic Properties of Stone Mastic Asphalt Reducing Tire/Road Noise (SMA LA)

Materials ◽

10.3390/ma13163446 ◽

2020 ◽

Vol 13 (16) ◽

pp. 3446

Author(s):

Wladyslaw Gardziejczyk ◽

Andrzej Plewa ◽

Raman Pakholak

Keyword(s):

Viscoelastic Properties ◽

Asphalt Mixture ◽

Crumb Rubber ◽

Low Noise ◽

Asphalt Mixtures ◽

Compression Tests ◽

Road Noise ◽

Stiffness Modulus ◽

Mastic Asphalt ◽

Stone Mastic Asphalt

The use of rubber granulate in the composition of asphalt mixtures, as well as the use of poroelastic layers, is indicated by many research centers as a factor with a positive effect on tire/road noise reduction. Attention is however paid to their lower structural durability compared to asphalt concrete (AC) or stone mastic asphalt (SMA). Stone mastic asphalt reducing tire/road noise (SMA LA) layers have also been recently used as low-noise road surfaces. The article presents the test results of viscoelastic properties of asphalt mixtures SMA8 LA, SMA8 LA containing 10%, 20%, and 30% of rubber granulate, with bitumen 50/70, bitumen 50/70 modified with styrene butadiene styrene (SBS) copolymer, crumb rubber, and mixtures with bitumen modified simultaneously with crumb rubber and SBS copolymer. The reference asphalt mixture was the porous asphalt (PA8). The presented results of water damage resistance, degradation resistance in the Cantabro abrasion loss test, stiffness modulus as a function of temperature and hysteresis loop proved that the amount of rubber granulate and the type of binder significantly affect the values of these parameters. Attention was paid to the possibility of using the results of uniaxial cyclic compression tests when determining the proportion of rubber granulate in SMA8 LA mixtures. Tests of hysteresis loops and stiffness modulus confirm much higher elasticity of SMA8 LA mixtures with rubber granulate as compared to mixtures without the addition of granulate.

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Recyclability of Asphalt Mixtures with Crumb Rubber Incorporated by Dry Process: A Laboratory Investigation

Materials ◽

10.3390/ma13122870 ◽

2020 ◽

Vol 13 (12) ◽

pp. 2870

Author(s):

Israel Rodríguez-Fernández ◽

Maria Chiara Cavalli ◽

Lily Poulikakos ◽

Moises Bueno

Keyword(s):

Urban Areas ◽

Mechanical Performance ◽

Asphalt Binder ◽

Aging Effect ◽

Crumb Rubber ◽

Low Noise ◽

Asphalt Mixtures ◽

Polymer Modification ◽

Modified Bitumen ◽

Dry Process

Semi-Dense Asphalt (SDA) mixtures are nowadays recommended for the surface layer of low noise roads in urban areas due to their optimal functional characteristics. Moreover, the use of polymer-modified bitumen (PmB) in its design results in high mechanical performance. However, this type of highly modified bitumen implies significant economic and environmental disadvantages. The polymer modification increases the production cost, involves higher mixing temperatures, and makes the recycling process of the asphalt mixtures challenging. As a potential alternative to PmB in SDA mixtures, this experimental work analyses the dry process for the incorporation of crumb rubber (CR) from waste tires. Particularly, the main objective was to study the aging effect and the recyclability of asphalt mixtures prepared in the laboratory with two different types of CR. The volumetric properties and mechanical performance of the mixtures artificially aged and rejuvenated were evaluated. The results obtained show that mixtures with CR have adequate performance, being less susceptible to aging than a conventional polymer-modified mixture. Furthermore, the rheological response of asphalt binder samples recovered from the mixtures at different aging states was analyzed. It was observed that the effect of the rejuvenator depended on the CR type, but this fact did not negatively influence the performance of the recycled mixtures.

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A Review on Improving Asphalt Pavement Service Life Using Gilsonite-Modified Bitumen

Sustainability ◽

10.3390/su13126634 ◽

2021 ◽

Vol 13 (12) ◽

pp. 6634

Author(s):

Hayder Al Hawesah ◽

Monower Sadique ◽

Clare Harris ◽

Hassan Al Nageim ◽

Karl Stopp ◽

...

Keyword(s):

Rheological Properties ◽

Hot Mix Asphalt ◽

Asphalt Binder ◽

Asphalt Mixture ◽

Asphalt Mixtures ◽

Asphalt Binders ◽

Modified Bitumen ◽

Dry Process ◽

Modified Asphalt ◽

Wet Process

Hot mix asphalt has various benefits such as good workability and durability. It is one of the most general materials used as asphalt mixtures in road pavements. Asphalt mixtures and binders can be improved by modifying them with various additives. Gilsonite is a natural asphalt hydrocarbon which may be used as an additive to hot mix asphalt. It is used as an asphalt binder modifier (wet process) and an asphalt mixture modifier (dry process) to improve the properties of the mix. It provides the option of improved rheological properties, stability, strength rutting resistance and moisture sensitivity. This paper examines the current research relating to the use of gilsonite to improve the asphalt properties (binder and mixture). The rheological properties of the modified asphalt binders and mechanical properties of the modified asphalt mixtures will be reviewed. The influence of adding gilsonite individually or combined with other additives will be discussed. Furthermore, assessment of the environmental and economic perspectives of the studied asphalt along with some suggestions to improve the asphalt binders and mixtures will be explored.

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The Addition of a High Dosage of Rubber to Asphalt Mixtures: The Effects on Rutting and Fatigue

Sustainability ◽

10.3390/su13179718 ◽

2021 ◽

Vol 13 (17) ◽

pp. 9718

Author(s):

Amin Chegenizadeh ◽

Pak Jing Shen ◽

Indah Sekar Arumdani ◽

Mochamad Arief Budihardjo ◽

Hamid Nikraz

Keyword(s):

Service Life ◽

Asphalt Mixture ◽

Road Construction ◽

Crumb Rubber ◽

Asphalt Mixtures ◽

Maintenance Costs ◽

Different Types ◽

Stone Mastic Asphalt ◽

Marshall Stability ◽

Positive Effect

Bitumen is subjected to cracks and damage during its service life. Adding a material with the potential to increase the durability of bitumen can expand its service life and reduce maintenance costs. Previous studies indicate that adding crumb rubber into asphalt has a positive effect on the performance of the mixture. Using crumb rubber may solve environmental problems due to vehicle tire waste disposal by reducing maintenance costs needed to increase asphalt’s strength. Some studies have investigated the effect of bitumen mixed with crumb rubber; however, it seems that the effect of different types of rubber mixtures used has been overlooked. Therefore, this study aims to better understand the effects of the increasing amount of rubber addition in various types of asphalt mixtures and determine the optimal mixture that could be used in road construction. A series of experiment was conducted, incorporating various tests (such as Marshall stability, rutting, and fatigue), to test various mixtures of asphalt in the form of dense-graded asphalt (DGA), fine gap-graded asphalt (FGG), gap-graded asphalt (Stone Mastic Asphalt, SMA), and open-graded asphalt. The amount of added crumb rubber was 25% by weight of bitumen. All mixtures were classified as superior in rutting and fatigue resistance, since they all reached a maximum depth of rutting less than 15 mm and generated two times more failure cycles compared to the conventional asphalt. The most optimal performance asphalt mixture was showed by the SMA10 mixture, resulting in a minimum rut depth of less than 1.2 mm and producing 750% more fatigue cycles than conventional asphalt. The result indicates that the addition of 25% of the rubber particles in the binder can increase the properties and durability of asphalt mixtures.

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Effects of Crumb Rubber Size and Concentration on Performance of Porous Asphalt Mixtures

International Journal of Polymer Science ◽

10.1155/2013/789612 ◽

2013 ◽

Vol 2013 ◽

pp. 1-10 ◽

Cited By ~ 19

Author(s):

Altan Cetin

Keyword(s):

Large Scale ◽

Resilient Modulus ◽

Asphalt Mixture ◽

Crumb Rubber ◽

Asphalt Mixtures ◽

Performance Characteristics ◽

Moisture Susceptibility ◽

Porous Asphalt ◽

Dry Process ◽

Abrasion Loss

The purpose of this study is to investigate the effect of size distribution and concentration of crumb rubber on the performance characteristics of porous asphalt mixture. The recycling of scrap tires in asphalt pavements appears as an important alternative providing a large-scale market. The characteristics of bitumen are very important with regard to service life of porous asphalt pavement. The experimental study consists of two main steps. Firstly, the mixture design was performed to determine the optimum bitumen content. In the latter step, the mixtures were modified by dry process using crumb rubber in three different grain size distributions of #4~#20, #20~#200, and #4~#200 and rubber content of 10%, 15%, and 20% as weight of optimum bitumen. The permeability, Cantabro abrasion loss, indirect tensile strength, moisture susceptibility, and resilient modulus tests were carried out on the specimens. Test results show that #20~#200 sized rubber particles reduced air voids and coefficient of permeability, while they increased the Cantabro abrasion loss. In general, increasing the crumb rubber size and content decreased the performance characteristics of the porous asphalt mixtures.

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Establishing Indicators and an Analytic Method for Moisture Susceptibility and Rutting Resistance Evaluation Using a Hamburg Wheel Tracking Test

Materials ◽

10.3390/ma13153269 ◽

2020 ◽

Vol 13 (15) ◽

pp. 3269

Author(s):

Wei-Han Wang ◽

Chien-Wei Huang

Keyword(s):

Inflection Point ◽

Asphalt Mixture ◽

Asphalt Mixtures ◽

Analytic Method ◽

Moisture Susceptibility ◽

Rutting Resistance ◽

Novel Method ◽

Wheel Tracking Test ◽

Wheel Tracking ◽

Hamburg Wheel Tracking

The Hamburg wheel tracking test (HWTT) is widely used to evaluate the performance of asphalt mixtures. According to HWTT specifications, the stripping inflection point (SIP) and the rut depth at a certain number of load cycles are two common indicators for evaluating the moisture susceptibility and rutting resistance of asphalt mixtures, respectively. Although these indicators have been used extensively by several transportation institutions, the reliability and stability in evaluating asphalt mixture behaviors of these indicators have been questioned. To more effectively evaluate the performance of asphalt mixture in the HWTT, this study introduces a novel method of analysis for the HWTT and novel indicators of rutting resistance and moisture susceptibility. The proposed method and indicators were employed to analyze the HWTT results of 14 field core specimens, and the proposed indicators were compared with conventional HWTT indicators to assess their capability of distinction between asphalt mixtures with different performance behaviors in the HWTT. The results indicate that the conventional HWTT indicators cannot effectively evaluate the asphalt mixtures with different performance in the HWTT. By contrast, the proposed analytic method and indicators have significant advantages to effectively evaluate and distinguish the rutting resistance and moisture susceptibility of asphalt mixtures.

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