A Review on the Effect of Crumb Rubber Addition to the Rheology of Crumb Rubber Modified Bitumen (original) (raw)
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Laboratory and Field Investigations of Polymer and Crumb Rubber Modified Bitumen
Journal of Civil Engineering and Architecture, 2014
In this paper, properties of new kind of modified bitumen are presented. Bituminous binder was modified with mix modification using polymer and additive of crumb rubber. Terminal blend process at the refinery was applied to produce the mixed modified binder. Laboratory tests were focused on the characterization of the properties of 45/80-55 CR binder with comparison to reference 50/70 and conventional polymer modified 45/80-55 bitumen. Based on conventional binder tests such as penetration, softening point and Fraass breaking point as well as BBR (bending beam rheometer) and DSR (dynamic shear rheometer) tests, rheological properties were investigated. For determination of stability of the polymer and crumb rubber, modified bitumen tube testing method was used. Based on the results analysis, improvement of the viscoelastic properties of polymer and crumb rubber modified bitumen was observed. Conventional properties and stability tests showed that it is possible to pass standard requirements for polymer modified bitumen. Mixed modification and terminal blend allow to use crumb rubber as a modifier with elimination of the separation of crumb rubber during transportation and storage at high temperature. In this paper, experience from filed sections with use of the asphalt mixture with new kind of modified bitumen is presented.
COMPARISON OF PHYSICAL AND RHEOLOGICAL PROPERTIES OF PLAIN AND CRUMB RUBBER MODIFIED BITUMEN
Bitumen is predominantly used to construct pavements for roads, highways, and airports. Due to the viscoelasticity nature of bitumen, it plays a predominant role in the performance of the pavements where temperature and rate of load application have a great influence. In India, the specifications for bituminous binders rely on different empirical tests which have almost no significance on their performance characteristics are reported. In this paper, the physical and rheological properties of bituminous binders commonly used in India, at high and intermediate field temperatures are reported in terms of their performance characteristics. Considering several factors that affect the behavior of bituminous binders, the effects of variations in temperature, rate of loading and amount of loading are considered. The changes in the properties of commonly used grades of (60-70) bitumen both unmodified and modified with crumb rubber have been reported. The Marshall properties and indirect tensile strength ratio are compared for the specimens prepared at optimum binder content (OBC) for bituminous concrete (BC) grading-2. Crumb rubber modified bitumen shows higher Marshall Stability, reduced flow, higher ITS ratio and improved rheological properties in terms of rutting.
Bitumen is predominantly used to construct pavements for roads, highways, and airports. Due to the viscoelasticity nature of bitumen, it plays a predominant role in the performance of the pavements where temperature and rate of load application have a great influence. In India, the specifications for bituminous binders rely on different empirical tests which have almost no significance on their performance characteristics are reported. In this paper, the physical and rheological properties of bituminous binders commonly used in India, at high and intermediate field temperatures are reported in terms of their performance characteristics. Considering several factors that affect the behavior of bituminous binders, the effects of variations in temperature, rate of loading and amount of loading are considered. The changes in the properties of commonly used grades of (60-70) bitumen both unmodified and modified with crumb rubber have been reported. The Marshall properties and indirect tensile strength ratio are compared for the specimens prepared at optimum binder content (OBC) for bituminous concrete (BC) grading-2. Crumb rubber modified bitumen shows higher Marshall Stability, reduced flow, higher ITS ratio and improved rheological properties in terms of rutting.
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.
Investigating the properties of crumb rubber modified bitumen using classic and SHRP testing methods
Construction and Building Materials, 2012
Considerable effect of crumb rubber on improving the original bitumen properties along with environmental and economical advantages, encouraged using this additive as an effective modifier. In this research, due to lack of enough information about the effects of crumb rubber produced in Iran on 0/70 bitumen properties, extensive laboratory investigations have been carried out using classic and SHRP testing methods. The results of classic tests showed that adding crumb rubber reduced penetration, temperature susceptibility, ductility and fraass breaking point and increased the softening point, elastic recovery and vialit adhesion. Rheological properties of modified specimens were investigated with DSR in temperature sweep and frequency sweep and creep tests before and after aging in RTFO. Results indicated that there was an inflection point or inflection interval in G ⁄ , G ⁄ /sind and G ⁄ Ásind diagrams. At higher temperatures and lower frequencies than the inflection point or inflection interval the aforementioned parameters increased by increasing the crumb rubber content and at lower temperatures and higher frequencies the reverse was true. Furthermore, increasing the crumb rubber content and aging in RTFO lead to reduce of creep and increase of viscosity quantity.
RHEOLOGICAL PROPERTIES OF CRUMB RUBBER MODIFIED BITUMEN CONTAINING ANTIOXIDANT
Rheology has become a useful tool in the characterization of the bitumen performance on the pavement. Visco -elastic properties of crumb rubber modified bitumen with antioxidants (CR30) were determined by the means of rheological measurement. This measurement led to a better knowledge of bitumen behavior that occurs when subjected to different thermal and mechanical conditions, as seen during road construction and services in the field. Dynamic Shear Rheometer (DSR) was used to characterize the rheology of the binders before and after oven aging. The binders were aged for 3 and 9 days. Results of a compatibility test showed that the addition of CR30 modified bitumen is compatible with the base bitumen. The results of unaged samples indicated that the addition of 1% CR30 and 5% CR30 modified binders caused an increase in G * value as a result of the rheological changes. Results showed that aging has significant influence on bitumen rheology, by increasing complex modulus and decreasing phase angle.
Study on Bitumen Modified with Crumb Rubber
2019
Bitumen is the main component for the road constructions which provides binding and adhesive properties. Bitumen is bio product of refined petroleum products and is used with aggregates for road construction. Bitumen plays a major role in binding of aggregates. This paper investigates the changes in properties of bitumen after adding crumb rubber, varying its percentages in the bitumen. Bitumen is actually the liquid binder that holds asphalt together. The term bitumen is often mistakenly used to describe asphalt. A bitumen-sealed road has a layer of bitumen spread and then covered with an aggregate. This is then repeated to give a two coat covering. The design and performance of bituminous concrete depends on the quality and percentage of binder used. As a part of this study it is tried to stabilised the bitumen by adding crumb rubber waste in shredded and fine form of particles Keywords-Bitumen, Crumb rubber, Ductility of bitumen, Stability of bitumen.
Materials Research-Ibero-American Journal of Materials, 2013
There is substantial evidence on the advantages of using crumb rubber in enhancing conventional bitumen properties, gaining environmental protection and boosting industrial-economical benefits. Thus, the use of this ingenious additive in bitumen modification through sustainable technology is highly advocated.The main objective of this research is to investigate the effects of different blending conditions (of time and temperature) and various crumb rubber contents on the properties of bitumen binders. Testing was conducted using the Dynamic shear rheometer (DSR) test and softening point test. The results showed that differing crumb rubber contents and blending temperature have significant effects on modified binder properties whereas the blending time showed an insignificant effect. Higher blending temperature and crumb rubber content were found to influence the interaction of bitumen-rubber blends and also increased the swelling rate of rubber particles, resulting in an increase in complex shear modulus (G*), storage modulus (G'), loss modulus (G") and softening point as well as a decrease in phase angle (δ). Thus, the modified bitumen became less susceptible to deformation after stress removals. The study also presented a considerable relationship between rheological parameters (G*, G', G' and δ) and softening point in terms of predicting physical-mechanical properties regardless of blending conditions. Thus, in terms of elasticity for the softening point data, the storage modulus and phase angle were found to be good indicators of binder elasticity. When softening point is made available, a prediction about binder ability to recover its original shape after stress removals can be done. http://www.scielo.br/scielo.php?pid=S1516-14392013000100015&script=sci\_arttext&tlng=es
Comparison between bitumen modified with crumb tyre rubber and styrene butadiene styrene
Historically, recycled rubber from tyre waste has been used in asphalt mixtures using two approaches, namely the wet process and the dry process. The wet process involves dispersing the rubber particles (known as crumb rubber modifier) in the bitumen to produce rubberised bitumen, which is then mixed with aggregate to form a mixture. In the dry process, on the other hand, the recycled rubber is mixed with the aggregates before introducing the binder to the mixture, i.e. rubber particles act as a partial replacement for some of the aggregate sizes. In the wet process, finely ground crumb rubber is blended with bitumen at an elevated temperature (170 to 200°C) generally in the presence of an oil extender. The interaction of bitumen with rubber in the wet process is known to be affected by the blending temperature, the duration of blending, the type and amount of mechanical blending energy, the size and texture of the rubber particles, and the aromatic component of the bitumen. The absorption of aromatic oils from the bitumen into the rubber's polymer chains causes the rubber to swell and soften. The type and amount of aromatic oil in the bitumen also plays a major role in determining the compatibility of bitumenrubber blends .
In this study, the performances of bitumen and asphalt mixtures modified by crumb rubber (CR) were compared with those modified by styrene-butadiene-styrene (SBS). The resultant mixtures were evaluated for their rheological and mechanical performances by different experimental techniques such as rheological bitumen tests, i.e., dynamic shear rheometer (DSR), bending beam rheometer (BBR), and hot mixture performance tests, that is, indirect tensile stiffness modulus, fatigue, semicircular bending, and toughness index. Experimental studies show that it is necessary to use twice as much CR as SBS to reach the same performance attained by SBS. CR modification at high additive content exhibits higher elastic response, i.e., recoverable strain, than the SBS-modified mixture. While the resistance to crack initiation of CR-modified mixtures increases with increasing additive content, the resistance to crack propagation decreases dramatically according to fatigue and semicircular bending tests.