Rheological characteristics of epoxy asphalt binders and engineering properties of epoxy asphalt mixtures – state-of-the-art

This study was conducted to assess the performance of modified asphalt binders and engineering properties of mixtures prepared with incorporation 3 vol% and 6 vol% of calcium carbonate (CaCO3), linear low-density polyethylene (LLDPE), and combinations of CaCO3 and LLDPE. The rheological properties of control and modified asphalt binders were evaluated using a series of testing such as rotational viscometer (RV), multiple stress creep recovery (MSCR) and bending beam rheometer (BBR) tests. Meanwhile, four-point beam fatigue test, the dynamic modulus (E*) test and tensile strength ratio (TSR) test were conducted to assess the engineering properties of asphalt mixtures. Based on the findings, the RV and MSCR test result shows that all modified asphalt binders have improved performance in comparison to the neat asphalt binders in terms of higher viscosity and improved permanent deformation resistance. A higher amount of CaCO3 and LLDPE have led modified asphalt binders to better recovery percentage, except the asphalt binders modified using a combination of CaCO3 and LLDPE. However, the inclusion of LLDPE into asphalt binder has lowered the thermal cracking resistance. The incorporation of CaCO3 in asphalt mixtures was found beneficial, especially in improving the ability to resist fatigue cracking of asphalt mixture. In contrast, asphalt mixtures show better moisture sensitivity through the addition of LLDPE. The addition of LLDPE has significantly enhanced the indirect tensile strength values and tensile strength ratio of asphalt mixtures.

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Studying viscosity of asphalt binders and effect of varied production temperatures on engineering properties of hot mix asphalt mixtures

Canadian Journal of Civil Engineering ◽

10.1139/cjce-2016-0383 ◽

2017 ◽

Vol 44 (1) ◽

pp. 1-9 ◽

Cited By ~ 6

Author(s):

Aboelkasim Diab

Keyword(s):

Ethylene Vinyl Acetate ◽

Hydrated Lime ◽

Asphalt Mixtures ◽

Engineering Properties ◽

Asphalt Binders ◽

Void Content ◽

Damage Evaluation ◽

Indirect Tensile ◽

Air Void ◽

Newtonian Behavior

The objectives of this paper are studying the viscosity characteristics of asphalt binders containing different additives, ethylene vinyl acetate, polypropylene, and hydrated lime, and the influence of varying mixing and compaction temperatures on the engineering properties of the corresponding mixtures. The engineering properties of the asphalt mixtures were investigated using the indirect tensile strength, moisture damage evaluation, and volumetric properties (in terms of the air void content). Based on the viscosity results, the non-Newtonian behavior of the asphalt binders prevails with the increase in the concentration of polymers and hydrated lime, thus the setting of the production temperatures using the equiviscous principle would be expected to be rather inaccurate. The variation in the production temperatures affected the engineering properties of the asphalt mixtures. It is recommended that a revision of the production temperatures from different methods be undertaken to satisfy the desired engineering properties for different conditions.

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State of the Art Study on Aging of Asphalt Mixtures and Use of Antioxidant Additives

Advances in Civil Engineering ◽

10.1155/2018/3428961 ◽

2018 ◽

Vol 2018 ◽

pp. 1-18 ◽

Cited By ~ 25

Author(s):

Okan Sirin ◽

Dalim K. Paul ◽

Emad Kassem

Keyword(s):

State Of The Art ◽

Asphalt Binder ◽

Asphalt Mixture ◽

Atmospheric Condition ◽

Asphalt Mixtures ◽

Asphalt Binders ◽

Asphalt Pavements ◽

Laboratory Environment ◽

Hardening Process ◽

Antioxidant Additives

The detrimental effects of hardening in asphalt pavements were first recognized by pioneering pavement engineers in the 1900s and have been studied extensively during the last 70 years. This hardening process, referred to as asphalt aging, is generally defined as change in the rheological properties of asphalt binders/mixtures due to changes in chemical composition during construction and its service life period. Aging causes the asphalt material to stiffen and embrittle, which affects the durability and leads to a high potential for cracking. This paper presents the state of the art on asphalt and asphalt mixture aging and use of antioxidant additives to retard the aging. A picture of complex molecular structure of asphalt and its changes due to atmospheric condition and various protocols used to simulate aging in laboratory environment are also discussed. Emphasis is given on recent studies on simulation of aging of asphalt mixtures as there has been limited research on mixtures compared to the asphalt binder. Finally, this paper presents the application of antiaging techniques and its mechanism, use of various types of antioxidant additives to retard aging of asphalt and, hence, improve the performance of asphalt pavements.

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Research of the Rheological Modification Mechanism of Crumb Rubber-Modified Asphalt Containing Polyamide 6 Additive

Advances in Civil Engineering ◽

10.1155/2020/8877487 ◽

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.

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

Materials ◽

10.3390/ma14092434 ◽

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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