Investigations of Physical and Rheological Properties of Aged Rubberised Bitumen (original) (raw)
Related papers
Journal of Engineering and Technological Sciences, 2020
Rubberized bitumen technology has been applied for a long time to enhance the performance of the asphalt pavement. In this research, the influence of natural rubber (NR) latex and crumb rubber (CR) on the conventional and rheological characteristics of 80/100 penetration grade bitumen before and after aging was compared. Conventional tests of penetration, ring and ball temperature, and ductility were conducted to evaluate the consistency of base bitumen and rubberized bitumen. A dynamic shear rheometer (DSR) test was carried out to evaluate the viscoelastic characteristics of the base and rubberized bitumen. The results showed that the addition of NR latex and CR reduced the penetration grade and increased the ring and ball temperature and ductility of the rubberized bitumen. This indicates that promising enhancement of the bitumen properties can be expected with the addition of NR latex and CR. The rheological properties analysis results showed that addition of CR up to 8% and NR l...
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.
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.
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.
Using Tyre Rubber as a Modifier in Asphalt to Improve Aging Resistance
2012
In recent times, a serious problem that leads to en viro ment pollution is the abundance and increase of waste tyre disposal. Larg e amounts of rubbers are used as tyres for cars and trucks etc. Despite the long run in se rvic , these tyres are not discarded. The major approach to solve this problem is to recycle and reuse of waste tyre rubber, and to reclaim of rubber raw materials. This research aims to investigate the effect of crumb rubber modifier concentration on the rheological an d physical properties of rubberised bitumen after aging. In order to evaluate the dura bility performance of rubberised bitumen, aging tests have been conducted using short-term ag ing (i.e., rolling thin film oven test or RTFOT) and long-term aging (i.e., pressure aging ve ssel or PAV). The results showed that the use of rubberised bitumen binder reduced the ag ing effect on physical and rheological properties of the bitumen binder as illustrated thr ough lower aging index of viscosity.
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.
A LABORATORY STUDY ON SHORT TERM AND LONG TERM AGEING OF BITUMEN USING MODIFIERS
The ageing of bitumen binder has an influence on how long is in service a road coating. Thus, it is important to have reliable methods to predict pavement behaviour with time. During its service period, bitumen suffers a gradual loss of its desirable properties due to continuous exposure of bitumen to environment and traffic. To determine changes of binder characteristics with respect to time, one must expose bitumen to the influence of external factors which results in oxidation, evaporation and exudation of bitumen components thus hardening of the bitumen. In the present study two modifiers i.e. Styrene Butadiene Styrene (SBS), an elastomer and Crumb Rubber, obtained from discarded tyres are used, to modify VG30 bitumen. The changes in conventional and rheological properties of VG30 modified with different percentages of SBS(5% to 7%) and Crumb Rubber(7% to 9%) before and after ageing are studied. The rheological properties of binders in terms of their complex modulus (G*) which depicts stiffness and overall resistance to deformation, storage modulus (G' = G*×cosδ) which measures energy stored during a loading cycle, loss modulus (G " = G* × sinδ) which measures the energy dissipated during a loading cycle and phase angle (δ), measures the viscoelastic character of bitumen are studied using Physica Smart Pave Asphalt Rheometer. The properties are tested at different temperature varying from 58˚C till failure at frequency 10 rad/sec. Short and Long Term ageing is simulated by Rolling Thin Film Oven Test and Pressure Ageing Vessel respectively. Conventional tests shows hardening of bitumen due to ageing and increase in viscosity and temperature susceptibility characteristics due to addition of modifiers. Complex Modulus G* increases with increase in % of modifier and test temperature, G* values are greater after RTFOT ageing which indicated hardening of bitumen and considerably greater after PAV ageing due to prolonged ageing. Rutting resistance (G*/sinδ) values are greater for modified bitumen indicating better rutting resistance. The third rheometer measurement Loss modulus (G* × sinδ) is carried out on PAV aged residue, to evaluate fatigue cracking property of binder.
Study of the bitumen aging effects on the rheological properties and fatigue behavior
2018
A study of bitumen aging effects on the rheological properties and fatigue behavior is carried out on five polymer modified bitumen provided by an oil company. Dynamic Shear Rheometer (DSR), is used to perform advanced experimental investigation. It allows practicing frequency sweep tests, fatigue tests and time sweep tests. Polymer modified bitumen with different percentage of SBS with or without the presence of crumb rubber are tested before and after short and long aging processes. Master curves were generated based on frequency sweep tests data, they are studied, and a comparison was conducted between each bitumen before and after aging. In this thesis, the DSR is presented, as well as the testing procedure and the tested materials. A fatigue life analysis of the results, based on the use of two different criteria, the first criterion is classically used: it consists in defining the failure as a 50% loss of the initial stiffness. The other criteria based on dissipated energy dat...
A Review on the Effect of Crumb Rubber Addition to the Rheology of Crumb Rubber Modified Bitumen
Advances in Materials Science and Engineering, 2013
Crumb rubber modification has been proven to enhance the properties of pure bitumen. This paper looks at some of the international standards for producing crumb rubber modified bitumen (CRMB) and reviews the effect of crumb rubber to the rheology of crumb rubber modified bitumen. The review shows that the rheology of CRMB depends on internal factors such as crumb rubber quantity, particle size, and pure bitumen composition, and external factors such as the mixing time, temperature, and also the modification technique. These factors govern the swelling process of crumb rubber particles that lead to the increase of viscosity of the modified bitumen. However, the mixing temperature and duration can cause rubber particles to depolymerize and subsequently cause loss of viscosity. Crumb rubber modification also improves the properties of bitumen by increasing the storage and loss modulus and enhancing the high and low temperature susceptibility. The effect of crumb rubber to aging properties of CRMB is also discussed. Finally several techniques of chemical modification to terminal blends of CRMB and the subsequent improvement to the settling property of CRMB are explained. © 2013 Mohd Rasdan Ibrahim et al. http://www.hindawi.com/journals/amse/2013/415246/abs/