Evaluating the Characteristics of Crumb Rubber Modified Asphalt Binders Produced with Neat Bitumen—Case of Kuwait (original) (raw)
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Effect of Crumb Rubber Modifiers (CRM) on Characteristics of Asphalt Binders in Sudan
The use of Crumb Rubber Modifiers (CRM) in flexible pavements to improve characteristics of asphalt binders has become a technique of great potential in recent years. In this regard an experimental program was undertaken to study the influence of CRM on the physical properties of asphalt binder. Asphalt cement modified with varying percentages of CRM, 0, 5, 10, 15, 20, and 30 percent were studied. Penetration, ductility, viscosity, softening point, flash and fire points, and specific gravity tests were performed on base and modified asphalts. The tests results show that addition of CRM to base asphalt has significant influence on its properties. Comparing the tests results, the viscosity, softening point, flash and fire points of the modified asphalts increased significantly, coupled with reduction in penetration and ductility as the CRM content increased. Addition of 15% CRM resulted in 200% and 15% increment in viscosity and softening point of base asphalt respectively, while the reduction in ductility and penetration were almost 75% and 25% respectively. It could be concluded that modification of asphalt binders by crumb rubber is successful and more beneficial technique.
Influence of Tire Crumb Rubber on Properties of Asphalt Binders
IOP Conference Series: Materials Science and Engineering, 2019
For many years, the asphalt binder has been used as the elemental material for pavement engineering. The increase in axle loads, heavy traffic, severe climate conditions and construction failures has led many researchers to seek some methods to enhance the bitumen properties. There is a wide range of applications of modifiers for bitumen in road construction. Although various kinds of modifiers have been used widely in reinforcing asphalt concrete, crumb rubber has attracted the most attention due to its high and desirable characteristics. It is realized that the well-distributed modifier can create a strong network in the internal structure of the composite, resulting in asphalt mastic that is more coherent. In the present paper, a laboratory investigation of the physical and rheological properties of various grades of asphalt binder (60-70 penetration grade, 80-100 penetration grade and PG-76 grade) modified with tire crumb rubber. The results showed improvement in physical proper...
Properties of Asphalt-Rubber Binders Related to Characteristics of the Incorporated Crumb Rubber
civil.uminho.pt
The behavior of asphalt binders modified with recycled crumb rubber depends on several factors, such as: rubber contents and type, temperature and time employed during the digestion process. This paper shows the results of a series of tests performed on asphaltrubber produced via the wet process. The tests included standard penetration, softening point, Brookfield viscosity and resilience. The results show that the limiting variable in the digestion process is the Brookfield viscosity. The influence of rubber type occurred especially in terms of Brookfield viscosity and softening point. There was a decrease in these properties for the asphalt-rubber binders produced with crumb rubber obtained by cryogenic process. Besides, the results show improvements in the modified binders properties, in terms of softening and resilience, when higher rubber content, temperature and digestion time are used.
Properties of Crumb Rubber and Latex Modified Asphalt Binders using Superpave Tests
MATEC Web of Conferences, 2018
Polymer modified binders have been used for long time to improve the quality of asphalt pavement. This study investigates the effect of crumb rubber and latex on the properties of bitumen binders. Crumb rubber and latex were added to the control 60/70 pen grade bitumen. Four different proportions of crumb rubber and latex were considered in this study: 0%, 4%, 6% and 8% by weight of bitumen binder. The effect of crumb rubber and latex were evaluated through standard penetration and softening point tests as well as dynamic shear rheometer (DSR) test. Temperature ranges of 20 o C-40 o C were used for the DSR rheological testing. The results showed that the addition of crumb rubber and latex leads to a promising improvement on the binder properties. A reduction in penetration and an increase in softening point temperature were observed with the addition of either crumb rubber or latex, this indicates improvement in stiffness and rutting resistance. The analysis on DSR results also show that the modified binders have good rutting resistance.
2021
Asphalt cement usually practices physical and chemical ageing process through the service life of the flexible pavement. Such ageing may be controlled by the addition of polymeric additives. An attempt has been made in the present investigation to assess the influence of implementing crumb rubber powder into three types of asphalt binder having the same penetration grade of (40-50) and obtained from three refineries. Samples of control and rubberized binders were subjected to short-term ageing process with the aid of thin film oven test apparatus. Specimens were subjected to physical and rheological properties determination before and after the ageing process. The rheological indices (penetration ageing index, ductility ageing index, creep stiffness, and softening point) were evaluated. It was concluded that penetration and the ductility ageing index increases after implementing 16 % crumb rubber by (2.7, 20, and 12.8) % and (13, 9.9, and 12.8) % for Dourah, Erbil, and Nasiriyah bin...
Rheology investigation of crumb rubber modified asphalt binders
KSCE Journal of Civil Engineering, 2010
The incorporation of crumb rubber into asphalt pavement mixes is designed to enhance binder properties through reducing the binder's inherent temperature susceptibility. During the interaction process, crumb rubber particles swell after absorbing a portion of the oils in the binder, resulting in the increase of binder viscosity. In this study, the Crumb Rubber Modified (CRM) asphalt binders were produced using virgin binder of Performance Grade (PG) 64-22 and ambient rubber with various concentrations (10%, 15%, and 20% by weight of virgin binder) in the laboratory. Rheological analyses (flow behavior, elasticity, loading dependence, and temperature dependence) of the control virgin binder and the CRM binders were conducted using a Bohlin Dynamic Shear Rheometer (DSR) II. The results indicated that (1) the use of crumb rubber as a modifier seemed to improve the penetration resistance of the asphalt binder because of the increased viscosity at 60 o C, (2) its advantage was more apparent at lower frequencies of loading, and (3) the asphalt binder with higher crumb rubber contents was observed to have better resistance to permanent deformation at higher temperatures and elasticity at lower temperatures.
An overview of crumb rubber modified asphalt
Roadways are considered one of the most important elements of infrastructure and they play an essential role in our daily lives. In road pavement construction, the use of crumb rubber in the modification of bitumen binder is considered as a smart solution for sustainable development by reusing waste materials. It is believed that crumb rubber modifier (CRM) could be one of the alternative polymer materials in improving bitumen binder performance properties of hot mix asphalt. This study aims to present and discuss the findings from some of the studies, on the use of crumb rubber in asphalt pavement.
International Journal of Physical Sciences, 2011
The increasing use of crumb rubber modifier in flexible pavements justifies the necessity for a better understanding of its physical and rheological properties as well as its elasticity behaviour. Basically the performance and properties of rubberised asphalt binder are influenced by the blending conditions and crumb rubber content. In this study, the laboratory investigation was conducted on crumb rubber modified asphalt binder properties as a function of two blending times (30 minutes and 60 minutes) and five crumb rubber contents (4, 8, 12, 16 and 20% by weight of asphalt binder) at mixing temperature of 180°C. Statistical analysis using two-way ANOVA was conducted on the results to evaluate the significance of rubber contents and blending times. The rubberised asphalt binder was evaluated in terms of binder elasticity and rutting resistance at high temperature. The results indicate that the crumb rubber content had a significant effect on G*/ sin (δ) at 76°C. The higher crumb rubber content appears to dramatically increase the elastic recovery and ductility. Statistical analysis showed significant effect of crumb rubber content in influencing the ductility, elastic recovery and G*/ sin (δ) values. Whereas the blending time do not appears to significantly affect the ductility, elastic recovery and rutting factor (G*/ sin (δ)) of the CRM asphalt binder. The asphalt binder with higher crumb rubber content and longer blending time of 60 minutes exhibited a higher value of elastic recovery. This indicates that crumb rubber modified asphalt binder has better resistance to rutting as compared to conventional asphalt binder. © 2011 Academic Journals. www.researchgate.net/publication/234411075\_Effect\_of\_blending\_time\_and\_crumb\_rubber\_content\_on\_properties\_of\_crumb\_rubber\_modified\_asphalt\_binder/file/9fcfd50fe03ace8b73.pdf
The increase use of crumb rubber in flexible pavements requires the better understanding of its effect on physical and rheological properties of rubberised bitumen binders. The performance properties of rubberised bitumen binder are influenced by the blending conditions and crumb rubber content. The main objective of this research is to investigate the effect of various crumb rubber content on the physical, rheological properties and rutting resistance of rubberised bitumen. Laboratory tests were conducted to evaluate such related properties of bitumen binder with different rubber contents. The tests undertaken comprise the ductility test, elastic recovery test, penetration test and dynamic shear rheometer (DSR) test. The results showed that the addition of crumb rubber has an effect on the physical properties of rubberised bitumen binders, by increasing its elastic recovery and decreasing its penetration and ductility. The rubberised bitumen binder with higher crumb rubber content has an obvious effect on the rheological properties (increase in complex shear modulus G*, storage modulus G', loss modulus G'' and decrease in phase angle ). The results indicated that the rubber content has the potential to resist rutting deformation that occurs in road pavement as result of increased traffic loading.
Case Studies in Construction Materials
Crumb rubber modifier (CRM) is one of the most popular asphalt binder modifiers due to the economic benefits and desired physical and rheological properties of asphalt binders and asphalt mixes. This research focuses on evaluating the properties of rubber-modified asphalt binders and selecting the best modified binder. The modified binders were produced by blending virgin binders with CRM at various contents of different gradations, and different methods of grinding. CRM made through ambient and cryogenic grinding methods with two gradation sizes were produced and tested. Three different virgin binders from two sources were obtained and used. The Analytic Hierarchy Process (AHP) method was used to determine the best combination of virgin binder and CRM, based on the rheological properties and their importance in Nevada's construction code. Based on AHP analysis, ambient CRM obtained the highest priority. CRM contents of 10% and 15% were ranked higher than 20% depending on the grade of the virgin binder. Both mesh 20 and 40 CRM sizes were favorable.