Review of "THE INFLUENCE OF CRUMB RUBBER MODIFIER (CRM) ON THE PROPERTIES OF ASPHALT CONCRETE MIXTURES"

The processes of introducing modifiers based on crumb rubber (CR) of waste tires into asphalt concrete mixtures are described. The distinctive features of the «Russian dry process» (PCT) modification of asphalt concrete (AС) with powder |modifiers (PM) obtained by the method of high-temperature shear grinding (HTSG) of CR or co-grinding of CR with thermoplastic elastomers are considered. An approach to the effectiveness evaluation of modification by rheological tests based on the Superpave methodology of «model binders» prepared under conditions close to those for the preparation of AС is proposed.

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Structural Layer Coefficients of Crumb Rubber–Modified Asphalt Concrete Mixtures

Transportation Research Record Journal of the Transportation Research Board ◽

10.3141/1583-08 ◽

1997 ◽

Vol 1583 (1) ◽

pp. 62-70 ◽

Cited By ~ 6

Author(s):

Mustaque Hossain ◽

Affan Habib ◽

Todd M. Latorella

Keyword(s):

Asphalt Concrete ◽

Crumb Rubber ◽

Asphalt Pavements ◽

Falling Weight Deflectometer ◽

Average Value ◽

Concrete Mixtures ◽

Mechanistic Approach ◽

Asphalt Mix ◽

Falling Weight ◽

Structural Layer

Structural layer coefficients for crumb rubber–modified (CRM) asphalt concrete mixtures were developed from the backcalculated moduli values using the falling weight deflectometer (FWD) test results on in situ pavements. Several test sections of recently built crumb rubber–modified pavements on three routes in Kansas (I-135, K-32 and US-56) were selected for this study. I-135 is a newly built asphalt pavement and the other two are gap-graded CRM overlays. Deflection data were collected with a Dynatest 8000 FWD at 21 locations at 7.5-m intervals on each test section on I-135, 22 locations on K-32, and 11 locations on US-56. For CRM asphalt mix overlays, the average surface layer coefficients from the equal mechanistic approach of analysis were found to vary between 0.11 and 0.46 with most values falling around 0.30. This indicates a lower structural layer coefficient value for the asphalt-rubber mix compared with the conventional asphalt concrete. For newly constructed CRM asphalt pavements, the structural layer coefficients varied from 0.25 to 0.48, with the average value around 0.35. These values are close to the design layer coefficient values used for conventional asphalt concrete layers. Large variabilities in computed structural layer coefficients for the rubblized jointed reinforced concrete pavement were observed. The structural layer coefficients computed for this layer varied from 0.10 to 0.35.

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Increasing the Stability of Asphalt Concrete Mixture Using Crumb Rubber

E3S Web of Conferences ◽

10.1051/e3sconf/202132810002 ◽

2021 ◽

Vol 328 ◽

pp. 10002

Author(s):

Fajar Romadhon ◽

Agata Iwan Candra ◽

Dwifi Aprillia Karisma ◽

Muhammad Heri Nastotok ◽

Rendy Kurnia Dewanta ◽

...

Keyword(s):

Asphalt Concrete ◽

Asphalt Mixture ◽

Road Construction ◽

Crumb Rubber ◽

Concrete Mixture ◽

Road Pavement ◽

Road Users ◽

Concrete Mixtures ◽

The Stability ◽

Marshall Stability

Stability is a measure of the strength of an asphalt mixture in resisting deformation due to loading. If a road construction structure cannot withstand the existing load, it will result in road damage that endangers road users. This study aims to improve the stability of the asphalt concrete mixture with the use of crumb rubber. Crumb rubber is used because it has good resistance and elasticity. The research was conducted experimentally by making test objects in the laboratory. In this study, five variations crumb rubber (2%, 4%, 6%, 8%, and 10% of the weight asphalt mixture) were carried out with the size of the powder retained on a 40 sieve. Marshall test and analysis of volumetric was carried out to determine the characteristics of the asphalt-concrete mixture. The results showed that the highest Marshall stability was obtained at 10% crumb rubber with a stability value of 1422 kg. The use of rubber powder can significantly increase the strength and quality of the asphalt-concrete mixture. Thus, crumb rubber can be used, and this percentage can be used as a reference in the manufacture of asphalt-concrete mixtures in order to obtain good road pavement quality.

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