scholarly journals Evaluation and optimization of asphalt binder and mixture modified with high activated crumb rubber content

2022 ◽  
Vol 314 ◽  
pp. 125676
Author(s):  
Qi Liu ◽  
Jinzhou Liu ◽  
Bin Yu ◽  
Jiupeng Zhang ◽  
Jianzhong Pei
Keyword(s):  
Asphalt Binder ◽  
Crumb Rubber ◽  
Rubber Content

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 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.

Properties and Ageing of Crumb Rubber Modified Bitumens

2017 ◽  
Vol 737 ◽  
pp. 535-540
Author(s):  
Ondrej Dasek ◽  
Petr Hyzl ◽  
Pavel Coufalik
Keyword(s):  
Elastic Recovery ◽  
Asphalt Binder ◽  
Crumb Rubber ◽  
Waste Materials ◽  
Complex Shear Modulus ◽  
Rubber Content ◽  
Shear Moduli ◽  
Needle Penetration ◽  
Complex Shear ◽  
Phase Angles

The issue of reusing waste materials is becoming very current and also includes reusing used tires. One of the possibilities is using these tires for the production of crumb rubber, which is added as a modifying agent into paving bitumens. The paper compares properties of this special type of asphalt binder with properties of conventional binders. In order to test the rheological properties, needle penetration, softening point, dynamic viscosity, resilience and elastic recovery tests were performed. Emphasis was put on description of rheological behavior determined using dynamic shear rheometer with the effects of ageing assessed using RTFOT method. It was found that crumb rubber modified bitumens have a higher stiffness in comparison to both paving and polymer modified bitumens. Ageing of crumb rubber modified bitumens led to an increase of complex shear moduli and decrease of phase angles. Increasing the crumb rubber content in bitumen leads to smaller increase of complex shear modulus due to ageing. It demonstrates higher resistance against ageing.

Evaluation of Adhesion Properties of Modified Asphalt Binders with Use of Binder Bond Strength Test

2017 ◽  
Vol 2632 (1) ◽  
pp. 88-98 ◽  
Author(s):  
Weidong Huang ◽  
Lu Zhou
Keyword(s):  
Bond Strength ◽  
Asphalt Binder ◽  
Gel Permeation Chromatography ◽  
Crumb Rubber ◽  
Asphalt Binders ◽  
Adhesion Properties ◽  
Rubber Powder ◽  
Positive Effects ◽  
Tracking Device ◽  
Styrene Butadiene

Moisture damage is a prominent problem of asphalt pavements. The bond strength between asphalt and aggregates is a crucial factor that influences the capability of asphalt to resist moisture-induced damage. In this study, a binder bond strength (BBS) test was conducted to evaluate the effects of various modifiers and additives of different amounts on bond strength between asphalt and aggregates. Furthermore, the influence of styrene–butadiene–styrene (SBS) on adhesion behavior of asphalt binder was investigated through a gel permeation chromatography (GPC) test. Finally, the results of the BBS test were compared with the findings obtained from a Hamburg wheel-tracking device (HWTD) test, which reflected the moisture sensitivity of mixtures under wet conditions. Results indicated that gilsonite, high-density polyethylene, and polyphosphoric acid improved the bond strength of the base asphalt; SBS had no positive effects on asphalt adhesion properties; and SBS at a low amount reduced the bond strength. Ethylene bis-stearamide wax, crumb rubber, terminal blend (TB) rubber powder, and compound modifier TB rubber powder plus SBS decreased the bond strength. The GPC test results showed that SBS possibly did not actively contribute to the formation of bond strength between asphalt and aggregates. Test data for BBS and HWTD tests under wet conditions confirmed that there was no discernible correlation between these two tests when adhesion properties of modified asphalts were evaluated. However, the results of the BBS test were in accordance with those of the HWTD test when the adhesion of asphalt with different amounts of the same modifier and the mixture resistance to water damage were evaluated.

A Study on the Influences of Crumb Rubber Modified Asphalt

2012 ◽  
Vol 204-208 ◽  
pp. 3899-3904
Author(s):  
Lan Yun Chen ◽  
Qing Long You ◽  
Xin Qiu
Keyword(s):  
Laboratory Tests ◽  
Mechanical Characteristics ◽  
Engineering Application ◽  
Crumb Rubber ◽  
Climatic Conditions ◽  
Pavement Performance ◽  
Rubber Content ◽  
Modified Asphalt ◽  
Truck Tire

In order to study the effects of different factors on the performance of crumb rubber modified asphalt, on the basis of many laboratory tests, this article analyzed such factors as types of crumb rubber, fineness, content, mixing temperature and matrix asphalt. Results show that mixed with the crumb rubber, pavement performance of the asphalt has been improved to varying degree. In the engineering application of rubber asphalt, it is suggested that the 20 mesh crumb rubber modified asphalt of truck tire be adopted, with about 16% to 18% of crumb rubber content at about 175°C. As for matrix asphalt, it should be selected according to the different climatic conditions and the mechanical characteristics of the pavement.

scholarly journals Low-Temperature Rheological Properties and Microscopic Characterization of Asphalt Rubbers Containing Heterogeneous Crumb Rubbers

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4120 ◽  
Author(s):  
Mingfeng Chang ◽  
Yixing Zhang ◽  
Jianzhong Pei ◽  
Jiupeng Zhang ◽  
Min Wang ◽  
...  
Keyword(s):  
Low Temperature ◽  
Rheological Properties ◽  
Fine Particles ◽  
Physicochemical Characteristics ◽  
Crumb Rubber ◽  
Rubber Content ◽  
Evaluation Indexes ◽  
Asphalt Rubber ◽  
Linear Viscoelastic Material ◽  
Microscopic Morphology

Asphalt rubbers mixed with untreated and plasticized crumb rubbers and a compounding coupling agent were investigated in this study. The low-temperature rheological properties of asphalt rubbers at different aging levels were tested using a dynamic shear rheometer (DSR). An interconversion between linear viscoelastic material functions was used to obtain converted evaluation indexes for the asphalt rubbers at low temperatures. Lastly, the physicochemical characteristics and the microscopic morphology of the asphalt rubbers were evaluated using Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM), respectively. In conclusion, the storage moduli of the asphalt rubbers containing heterogeneous crumb rubbers increased with the plasticized crumb rubber content and the aging level. The converted relaxation moduli were consistent with the change trend of the storage moduli, and the relaxation rate decreased as the plasticized crumb rubber content and the aging level increased. The process of mixing the base asphalt with crumb and plasticized crumb rubbers was physical blending, and the effect of aging on the absorption peak change of asphalt rubber with plasticized crumb rubbers was less than that of asphalt rubber with ordinary crumb rubbers. Aging deteriorated the blending between the crumb rubber and the base asphalt, and a distinct interface appeared between the crumb rubber and the base asphalt. The particle cores of the plasticized crumb rubber in the asphalt rubber were difficult to maintain. Furthermore, as the plasticized crumb rubber content increased, more fine particles stripped off the plasticized crumb rubber after aging.

Laboratory Evaluation of Rubberized Binder and Mix Containing a Low Content of Devulcanized Rubber Modifier

2020 ◽  
Vol 2674 (11) ◽  
pp. 53-63
Author(s):  
Yanlong Liang ◽  
David Jones ◽  
John T. Harvey ◽  
Jeffery Buscheck
Keyword(s):  
Asphalt Binder ◽  
Fatigue Cracking ◽  
Laboratory Evaluation ◽  
Rubber Content ◽  
Area Index ◽  
Lower Phase ◽  
Waste Tires ◽  
Stiffness Reduction ◽  
Rubber Particles ◽  
Devulcanized Rubber

This paper evaluates the mechanical properties of rubberized asphalt binder and mix containing 5% and 10% rubber. This rubberized asphalt binder was manufactured in a field-blend process using devulcanized rubber particles, finer than 250 microns, derived from waste tires. Comparison between the rubberized binder and the base binder test results showed that the rubberized binders had higher complex moduli and lower phase angles at the grade temperature. They also had a higher percentage recovery in the multiple stress creep recovery test, and a significant creep stiffness reduction in the bending beam rheometer test. Given the low rubber content and small rubber particle size, this rubberized binder can be used in dense-graded mixes, whereas asphalt rubber binders, with larger rubber particles and higher rubber content (>15%), must be used in gap- or open-graded mixes. This rubberized dense-graded mix met the volumetric design criteria at the same binder content as the control mix prepared with the unmodified base binder. Laboratory tests on the mix included repeated load triaxial, Hamburg wheel track, flexural dynamic modulus, and beam fatigue. The rubberized mixes had slightly lower stiffnesses than the control mix, but better resistance to moisture damage, rutting, and fatigue cracking. A strong linear correlation was found between the carbonyl area index and the rheological properties of the long-term aged binder and fatigue life of the mixes. Based on these findings, these rubber-modified binders can be considered for use in dense-graded mixes to improve overall performance and make use of waste tires.

Sign in / Sign up

Export Citation Format

Share Document