scholarly journals Assessment of simultaneous incorporation of crumb rubber and asphaltite in asphalt binders

DYNA ◽  
2019 ◽  
Vol 86 (208) ◽  
pp. 257-263
Author(s):  
Javier Eduardo Mantilla Forero ◽  
Eduardo Alberto Castañeda Pinzón

Every day, roads are submitted to greater stresses. Thereby, additives have been incorporated to asphalt mixtures to enhance pavements performance. The purpose of this experimental study is to characterize for the first time, to date, the viscoelastic properties of asphalt samples modified with recycled rubber —from used vehicles tires— and asphaltite in the same mixture, at different temperatures and frequencies. All with the aim of optimizing the material properties and coming up with a proposal to an environmental issue: discarded vehicles tires and their after-service use. The stiffness of briquettes was analyzed by axial compression test. The results were principally represented in Black Space and Cole-Cole plot and indicate a substantial increase in stiffness and elasticity of the modified asphalt throughout the whole temperature range. This shows that the simultaneous addition of these two ingredients to the bitumen is a favorable alternative in road construction using asphalt pavements.

2012 ◽  
Vol 256-259 ◽  
pp. 1837-1844 ◽  
Author(s):  
Iman Mohammadi ◽  
Hadi Khabbaz

The use of modified asphalt binders has become much more common over the past two decades. Many types of modifier have been used in paving asphalts to enhance the performance of asphalt pavements in a wide range of climates and loading conditions. Among various asphalts binder modifiers, the recycled crumb rubber has been used very successfully for many years. Generally in production of CRM binder, mixing and compaction temperature is determined by measuring of binder viscosity. The ordinary method used for viscosity measurement of unmodified binder leads to a very high Mixing and Compaction Temperature (MCT) for CRM binder. The aims of this paper are to identify, develop and give some recommendations on a reliable laboratory approach for blending of CRM with binder, as well as introducing appropriate laboratory test methods for optimisation of MCT of crumb rubber modified binder asphalt.


2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Zhihua Tan ◽  
Jijing Wang

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.


Environments ◽  
2021 ◽  
Vol 8 (6) ◽  
pp. 47
Author(s):  
Lim Min Khiong ◽  
Md. Safiuddin ◽  
Mohammad Abdul Mannan ◽  
Resdiansyah

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.


Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2434
Author(s):  
Laura Moretti ◽  
Nico Fabrizi ◽  
Nicola Fiore ◽  
Antonio D’Andrea

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.


Author(s):  
Pouria Hajikarimi ◽  
Alireza Sadat Hosseini ◽  
Fateh Fakhari Tehrani ◽  
Mohammad Rahi ◽  
Joseph Absi ◽  
...  

2020 ◽  
Vol 2020 ◽  
pp. 1-17 ◽  
Author(s):  
Nonde Lushinga ◽  
Liping Cao ◽  
Zejiao Dong ◽  
Chen Yang ◽  
Cyriaque O. Assogba

This research was conducted to elucidate better understanding of the performance of crumb rubber asphalt modified with silicone-based warm mix additives. Two different silicone-based warm mix asphalt (WMA) additives (herein Tego XP and Addibit) were used to prepare crumb rubber modified (CRM) warm mix asphalt binders. The viscosity of these CRM binders was measured at different temperatures and shearing rates. Furthermore, softening point and penetration tests, Multiple Stress Creep Recovery (MSCR), Time Sweep (TS), Atomic Force Microscopy (AFM), Frequency sweep (FS), and Fourier Transform Infrared (FTIR) tests were also conducted on prepared samples. Based on these robust and rigorous laboratory experiments, it was established that viscosity of CRM binders was reduced by addition of Tego XP and Addibit WMA additives. However, WMA additives had different influence on rheological properties of the binder. CRM binder with Tego XP improved resistance to rutting of the binders but would degrade the fatigue performance. On the contrary, viscoelastic continuum damage (VECD) model results and those of phase angle approach revealed that the binder with Addibit improved resistance to fatigue cracking of the binders but had no adverse effects on high temperature rutting performance. FTIR test results established a presence of polydimethylsiloxane (PDMS) in CRM binders with Tego XP and Addibit. PDMS is a well-known hydrophobic organic and inorganic polymer that is water repellent; therefore, binders containing these silicone-based warm mix additives could be beneficial in resisting moisture damage in asphalt binders and mixtures. Morphology of CRM binders with and without WMA revealed good distribution of the rubber particles in asphalt binder matrix. Further addition of WMA increased surface roughness of the binder, which can be correlated to changes in microstructure properties of the binder. Therefore, the study concluded that addition of Tego XP and Addibit reduces viscosity and improves mechanical properties of the asphalt binder.


2020 ◽  
Vol 10 (12) ◽  
pp. 4187
Author(s):  
Luís Picado-Santos ◽  
João Crucho

This Special Issue is dedicated to the use of nanomaterials for the modification of asphalt binders to support the analysis of the relevant properties and to determine if the modification indicated a more efficient use of asphalt mixtures’ fabrication or their modification in the context of asphalt mixtures’ fabrication and the improvement (or lack thereof) of these last ones to constitute effective asphalt pavement layers [...]


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