scholarly journals Improving the Aging Resistance of Asphalt by Addition of Polyethylene and Sulphur

2020 ◽  
Vol 6 (5) ◽  
pp. 1017-1030
Author(s):  
Maria Iqbal ◽  
Arshad Hussain ◽  
Afaq Khattak ◽  
Kamran Ahmad

With the increase in demand of flexible pavements, due to their various advantages over rigid pavements, there is a need to improve the aging properties of the bitumen in order to enhance its resistance against different types of distresses such as rutting, fatigue cracking. This research focus on the use of one polymeric additive Polyethylene (PE) and one non polymeric additive Sulphur (S) to enhance the aging resistance of asphalt. These modifiers are evaluated for their effect on the aging mechanism in comparison with the unmodified bitumen. Aging of the original and modified bitumen is realized by the Rolling Thin Film Oven (RTFO) and Pressure Aging Vessel (PAV). Physical properties of the aged and unaged asphalt binders are evaluated through empirical testing like penetration, ductility and softening point test. Optimum content of the modifiers is obtained by comparing the results of conventional properties before and after aging. Fourier Transformed Infrared Spectroscopy (FTIR) and Scanning Electron Microscope (SEM) are performed to bring out the chemical and morphological changes in the modified binder. Rheological properties of modified asphalt are evaluated with the help of a Dynamic Shear Rheometer (DSR). Results indicate improvement in physical properties of the modified asphalt even after the aging. Penetration index increased which shows less temperature susceptibility of the modified binders. Carbonyl and sulfoxide index are used as aging indicators which shows reduction in case of modified samples. Decrease in the sulfoxide and carbonyl index indicates better oxidation resistance of the modified samples. Morphological analysis proves good compatibility of the modifiers with asphalt binders. DSR results indicate improved viscoelastic properties of the modified binders. Hence it can be concluded that Polyethylene and Sulphur are good options to improve the aging resistance of asphalt in terms of their cost effectiveness and environment friendly nature.

2009 ◽  
Vol 620-622 ◽  
pp. 497-500 ◽  
Author(s):  
Shao Peng Wu ◽  
Jin Gang Wang ◽  
Yuan Zhang

After a preliminary investigation on the binary asphalt/clay binder, the ternary binder was prepared by adding the nanoclay and TAFPACK-SUPER (TPS) to the original asphalt. The previous research shows that exfoliated/intercalated layers homogeneously are dispersed in the asphalt matrix and the nanocomposite has formed. Rotation Thin Film Oven Test (RTFOT) and Pressure Age Vessel Test (PAV) results indicate that the modified asphalt with 3% organic nano-montmorillonite (OMMT) present better performance of aging resistance. The purpose of this research is to attain ternary asphalt binder with better rheological performance and aging resistance. The ternary modified asphalt binder containing 4% OMMT and 12% TPS by weight were prepared at the laboratory scale using high speed shearing mixer. The rheological properties of OMMT/TPS modified asphalt binders were evaluated before and after aging in present paper. Temperature sweep tests and frequency sweep tests were conducted to characterize the rheological properties of modified asphalt using Dynamic Shear Rheometer (DSR). According to the frequency sweep tests, complex modulus master curves were plotted to analysis the rheological properties. The results indicate that nanoclay/TPS/asphalt ternary binders have more excellent performance of rheological and aging resistance at both high and low temperatures, compared with the virginal bitumen and TPS modified asphalt.


Author(s):  
Ovidijus Šernas ◽  
Donatas Čygas ◽  
Audrius Vaitkus ◽  
Vytautė Gumauskaitė

Rubber derived from grinding of recycled cars and trucks tyres may be successfully used as a bitumen modifier. Number of researches reported sufficient characteristics of rubber modified asphalt binders or modified asphalt mixes in terms of improved permanent deformation and fatigue cracking. The behavior of crumb rubber asphalt binders depends on several factors, such as modification method, rubber content and size, modification temperature, mixing speed and time applied during the digestion process. The aim of this study is to evaluate the effect of crumb rubber amount and type on modified bitumen low and high temperature properties. This paper presents results of unmodified bitumen, crumb rubber crumb rubber and polymer modified bitumen. Low and high temperature properties have been evaluated using bending beam rheometer and dynamic shear rheometer. Moreover, softening point and viscosity tests have been performed. The study results revealed that crumb rubber modified bitumen performed better than pure bitumen and similarly to polymer modified bitumen.


2020 ◽  
Vol 17 (1) ◽  
pp. 34
Author(s):  
Sady A. Tayh ◽  
Rana A. Yousif ◽  
Qais S. Banyhussan

For a long time, bitumen has been utilized as the essential material for asphalt pavement construction. The factors of increasing axle loads, increasing traffic movement, critical climate conditions and many forms failures in construction have steered many researchers to seek some methods to enhance the asphalt binder properties. Even though various types of modifiers have been utilized in strengthening asphalt concrete, fibers have attracted the most attention due to their high and desirable characteristics. It is realized that the good distribution of the modifier in asphalt binder can generate a strong network in the interior structure of the blend, causing bitumen mastic to be more coherent. In this study, a laboratory investigation of the rheological and physical properties of various grades of bitumen modified by two types of fibers was conducted. Three grades of asphalt were used in this study (60-70 penetration grade, 80-100 penetration grade and PG-76 grade) with two types of fibers with different percentages- Cellulose oil palm fiber (COPF) (0.15, 0.3, 0.45, 0.6, and 0.75%) by weight of asphalt and carbon fiber (0.75, 1.25, 1.75, 2.25, and 2.75%) by weight of asphalt. The results showed enhancement in physical performance of the modified bitumen in terms of the decrease in penetration values, as well as a rise in the softening point and viscosity values. The fibers’ modified asphalt binders showed improved rheological properties and can raise the grade of asphalt depending on the base asphalt type.


2019 ◽  
Vol 9 (8) ◽  
pp. 1567 ◽  
Author(s):  
Huang Xiaoming ◽  
Ismail Bakheit Eldouma

The overall objectives of this study were to determine the most appropriate additive for improving the physical properties and the medium- and high-temperature performances (mechanical performance) of asphalt binders. Three different types of modified binders were prepared: crumb rubber modifier (CRM), polypropylene (PP), and tafpack super (TPS), which had concentrations of 2%, 3%, 3.5%, and 4% by weight of asphalt binder, for each modifier. Their physical and rheological properties were evaluated by applying various tests such as ductility, rotational viscosity, toughness, and tenacity, as well as the dynamic shear rheometer (DSR) test. As a result, the physical properties of the modified bitumen binders were compared, as were the medium- and high-temperature performances (mechanical performance), which had temperatures of 58, 64, 70, 76, 82, and 88 °C, respectively. This was how the most appropriate modifier was determined. The results demonstrated that the asphalt binder properties significantly improved by utilizing CRM followed by PP and TPS modifiers. The increase in the rutting parameter (G*/sin(δ)) after asphalt modification indicated its excellent performance at both medium- and high-temperatures. Lastly, the CRM was determined as the most preferred additive because of its positive effect on the physical properties and enhancement of the medium- and high-temperature performance (mechanical performance).


2017 ◽  
Vol 79 (6) ◽  
Author(s):  
Nura Bala ◽  
Ibrahim Kamaruddin ◽  
Madzlan Napiah

Polymer modified bitumen (PMB) has been used for many years to improve the performance of asphalt concretes against premature pavement defects. In this research, modified samples were prepared with 2%, 3%, 4%, 5% and 6% Linear Low Density Polyethylene (LLDPE) polymer by weight of bitumen binder. The influence of LLDPE polymer was evaluated through binder properties test which includes penetration, softening point, storage stability, temperature susceptibility, rutting, fatigue and thermal oxidative aging resistance from a dynamic shear rheometer (DSR) measurements at a temperature of 20 OC to 60 OC. Results show that LLDPE polymer has a significant effect on binder properties. Penetration decreases and softening point increases with increasing LLDPE content on the modified binder after aging, which implies LLDPE improves the thermo oxidative aging resistance of the binder. Furthermore, the storage stability test shows that at higher LLDPE concentrations phase separation may occur. DSR analysis shows that modified binders have lower temperature susceptibility and higher aging resistance with increased stiffness and elastic behavior compared with unmodified binders. In addition, modified binders show enhanced resistance against high temperature rutting and at low temperature fatigue performance. It was found that the optimum LLDPE content is 6%.


2010 ◽  
Vol 37 (1) ◽  
pp. 17-24 ◽  
Author(s):  
Hakseo Kim ◽  
Soon-Jae Lee ◽  
Serji N. Amirkhanian

This study presents an experimental evaluation for the performance properties of polymer modified asphalt (PMA) binders containing warm mix asphalt (WMA) additives. The PMA binders with the additives were produced using two of the available warm asphalt processes (i.e., Aspha-min and Sasobit) and three PMA binders graded as performance grade (PG) 76-22. The warm PMA binders were artificially short-term and then long-term aged using the rolling thin film oven (RTFO) and pressure aging vessel (PAV) procedures. Superpave binder tests were carried out on the binders through the rotational viscometer (RV), the dynamic shear rheometer (DSR), and the bending beam rheometer (BBR). In general, the results of this research indicated that (1) the addition of the WMA additives into the PMA binders showed positive effects on increasing rutting resistance at high temperature (based on the high failure temperature values from the DSR test); (2) the PMA binders containing the additives were observed to be less resistant to fatigue cracking at intermediate temperatures compared to the control PMA binders (based on the G*sin δ values at 25 °C from the DSR test); and (3) the addition of wax additive represented a possible lower resistance on low temperature cracking (based on the stiffness and the m-value at –12 °C from the BBR test).


Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1985
Author(s):  
Clara Celauro ◽  
Edwina Saroufim ◽  
Maria Chiara Mistretta ◽  
Francesco Paolo La Mantia

Polymer-modified bitumen (PMB) is bitumen that has been specifically engineered with polymer for providing enhanced performance in service. The aging of bitumen is a main aspect that is able to affect its final performance: during the production phase in a hot mix plant, all the binders experience short-term aging due to the high processing temperature. The same is true during the production of the modified binder, when the polymer is dispersed at high temperature in the bitumen mass. This paper aims at studying the effect of short-term aging when using different types of modifiers such as recycled polymers obtained from waste materials. A 50/70 penetration-grade bitumen has been modified, and bitumen characterization has been carried out before and after short-term aging; conventional tests, viscosity measurements, and dynamical mechanical analysis have been used to investigate the properties. Different aging indices have been determined for predicting the effect of short-term aging based on the type of modifier. Furthermore, the morphology of the modified bitumen has been investigated via fluorescent microscopy, before and after aging, in order to highlight morphological changes due to aging. The results confirm that aging affects all the modified binders, due to the thermal stress imposed during PMBs production. Nevertheless, polymer modification is proved to reduce the aging effect in terms of an increase in the elastic modulus as experienced by the original binder.


2017 ◽  
Vol 50 (3) ◽  
pp. 256-275 ◽  
Author(s):  
Mahdi Delaviz Bayekolaei ◽  
Koorosh Naderi ◽  
Fereidoon Moghadas Nejad

In recent years, the use of nano materials for improving various mechanical and performance-related properties of polymer-modified asphalt binders has been growing rapidly. However, few researches investigated the effects of base binder and styrene–butadiene–styrene (SBS) structure on rutting resistance of polymer-nanocomposite-modified asphalt mixtures. This study investigated the effect of polymer–nanocomposite modification, using two different penetration grade asphalt binders and two types of SBS, on rutting properties of asphalt mixtures. Rheological properties of modified binders, Marshall stability, resilient modulus, and rut depth in wheel-tracking tests were used to evaluate the rutting performance of the modified binders and mixtures. The results indicated that both base binder type and SBS structure had significant effect on rutting resistance of polymer-nanocomposite-modified asphalt mixtures.


2016 ◽  
Vol 78 (7-2) ◽  
Author(s):  
Ahmad Nazrul Hakimi Ibrahim ◽  
Nur Izzi Md. Yusoff ◽  
Norliza Mohd Akhir ◽  
Muhamad Nazri Borhan

This study was conducted to investigate the physical properties and storage stability of the 80/100 penetration grade asphalt modified with geopolymer. In this research, fly ash and alkali activators, namely sodium silicate (Na2SiO3) and sodium hydroxide (NaOH), were used as geopolymer components. The penetration, Ring and Ball softening point, ductility, and viscosity tests were conducted to determine the physical properties of geopolymer modified asphalt (GMA). Five samples of asphalt binders with varying percentages of geopolymer, namely 0, 3, 5, 7 and 9%, by weight of asphalt binder were studied. Results show that geopolymer has good compatibility with asphalt binder. The addition of geopolymer into asphalt binder resulted in improved permanent deformation resistance of the modified binder compared to that of the conventional asphalt. In conclusion, geopolymer could be considered as a potential alternative in the modification of the properties of asphalt binder.


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