The Effect of Ageing on Physical and Chemical Properties of Asphalt Cement (original) (raw)
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Effect of Aging on the Properties of Asphalt and Asphalt Mixtures
Ingenieria y Universidad, 2015
This article presents the results of the analysis of the effect of aging on the properties of asphalt and asphalt mixtures. The objective of this study was to compare the properties of the original asphalt and aged asphalt and the dynamic modulus of asphalt mixtures. The long-term aging was simulated by using Pressure Asphalt Vessel (PAV). Marshall and RAMCODES methodologies were used to determine the formula of work; values of dynamic modulus of designed mixtures were obtained by the indirect tensile test, using the Nottingham Asphalt Tester (NAT). The results showed an increase in the rigidity of the aged asphalt. Also, an increase of the stability and a decreased flow in the mixtures made with this type of binder was found. The dynamic modulus values of the mixtures containing aged asphalt showed an increase up to three times compared with those elaborated with original asphalt mixtures.
IAEME, 2019
The phenomenon of aging of asphalt binders and asphalt mixtures impacts directly in the physical-mechanical response and durability of asphalt pavements. Because of such reason, multiple research efforts have been carried out in relation to this topic. By conducting a deep bibliographical review, the most important aspects that the pavement engineer needs to be aware of in relation to the aging of asphalt binders and asphalt mixtures were organized and summarized. This information was summarized and described in two articles. This first one (Titled Part I), introduces and describes the changes that physical-chemical properties of asphalt binders and asphalt mixtures undergo when they age. Additionally, commonplace tests for attempting to evaluate said properties in these materials are introduced.
Comprehensive evaluation of long-term aging of asphalt mixtures in hot climatic condition
Road Materials and Pavement Design, 2018
Aging is an inevitable phenomenon in hot mix asphalt production and during in-service period of flexible pavement operation. This paper presents an experimental evaluation of long-term aging of asphalt mixtures in Qatar. Aging of asphalt mixture was conducted on two different states i.e. (1) traditional compacted specimen at a temperature of 85°C and (2) loose mixtures at an elevated temperature of 135°C. Test results indicated that the current practice of asphalt mixture conditioning in a forced-draft oven to simulate long-term aging in the field is not sufficient for pavements in Qatar which experience the hot climatic condition. To simulate long-term aging of asphalt mixture in field, oven aging duration needs to be extended from the standard 5 days at a temperature of 85°C for compacted specimens to 75 and 45 days for wearing and base layer, respectively based on the dynamic modulus test results. Conditioning on loose mixtures at an elevated temperature of 135°C can be an alternative option in terms of time efficiency and cost.
Influence of ageing on temperature susceptibility of asphalt concrete
2020
Asphalt cement is supplied by multiple different refineries in Iraq. The wide variation in environmental condition all over the country had led the flexible pavement to practice a considerable variation in surface temperature, ranging from 15°C to more than 65°C. Ageing potential of the asphalt binder is variable. An attempt has been made in the present investigation to assess the influence of short and long term ageing on temperature susceptibility of asphalt concrete prepared by using dense graded aggregate and three types of asphalt binder obtained from Daura, Erbil, and Nasiriyah refineries located at middle, north and south regions of the country. Asphalt cement samples were subjected to the classical physical properties’ determination, stiffness modulus, penetration index, and creep stiffness. Asphalt concrete specimens of 102 mm in diameter and 63.5 mm in height were prepared using the prementioned binders and subjected to temperature susceptibility determination. It was conc...
Evaluation of Short-Term Aging Protocol for Asphalt Mixtures
Applied Sciences, 2019
Asphalt mixtures are subjected to short-term aging during the production, placement, and compaction processes. Proper evaluation of asphalt pavement performance relies on the accurate characterization of asphalt mixtures during the design stage. In this study, three different loose asphalt mixtures often used in Qatar were evaluated to develop a laboratory short-term aging procedure. Sample mixtures 1 and 3 were collected from a construction site, while mixture 2 was obtained from an asphalt plant. Virgin aggregates and binders were also collected to reproduce the mixtures in the laboratory. Laboratory-produced mixtures were conditioned at 135 °C using various time durations. The mechanical properties of laboratory-produced mixtures were compared to those of mixtures produced on site. The results of the mechanical and binder testing demonstrated that the proper short-term aging protocol for asphalt mixtures often used in road construction in the State of Qatar would involve heating ...
Influence of Polymeric Additives on Ageing Indices of Asphalt Binder
2021
Ageing of asphalt binder is a vital property in the durability and sustainability of asphalt concrete pavement. Ageing usually occur due to evaporation of volatiles throughout the service life of the pavement. An attempt has been made in this investigation to assess the changes in ageing index of asphalt binder after implication of polymeric additives such as crumb rubber and polyethylene. The ageing index was assessed through various physical testing procedure such as penetration, softening point and ductility. It was noted that the ageing index in general decline after implication of crumb rubber by (7.6 and 13.8) % and (61 and 67.8) % for penetration and ductility testing after the addition of (8 and 16) % of crumb rubber respectively. However, the ageing index increases by (31.2, 36.4 and 45) % , (5, 8.7, and 16.5) % for penetration and softening point testing after implementing (0.5, 1.0, and 1.5) % of polyethylene into the asphalt binder. It was concluded that implication of c...
Characterisation of ageing processes on the asphalt mixture surface
Road Materials and Pavement Design, 2014
Aging of asphalt binders leads to damage on pavements, due to changes in their rheological behavior and in the binder composition. A hardening of the asphalt can be observed, mainly caused by the oxidation of the asphalt binder itself. Oxidation rate is influenced by temperature, ultraviolet radiation and intrinsic characteristics of materials. In order to be characterized, the binder is extracted from the field-aged asphalt cores that use to have several centimetres in thickness. The aging process, however, depends on the access of oxygen into the field core which varies with the distance from the pavement surface. In order to know the aging conditions of the pavement surface (only) and to evaluate their influence on the adhesion characteristics, it is necessary to recover the surface asphalt binder. Only the surface binder is exposed to ultraviolet rays and weathering. A new test method has been developed in this work. It is based on the asphalt binder recovery from the upper part of the asphalt mixture layer. This method was validated by the infrared spectrometry through comparison with the neat asphalt binder (aged and not aged) and with the conventional extraction. In addition, an accelerated aging protocol was developed with the use of a climate chamber comprised of brightness settings, and moisture and weather conditioning, to relate to the French climate. The aging results obtained in the laboratory and in the field were compared using the same test method. This comparison allowed the establishment of an accelerator factor with respect to the increase of sulfoxide and carboxyl groups. This study provides a better understanding of the influence of aging on the skid resistance and the ability of the material to resist to polishing.
Heating of asphalt during production and construction causes the volatilization and oxidation of binders used in mixes. Volatilization and oxidation causes degradation of asphalt pavements by increasing the stiffness of the binders, increasing susceptibility to cracking and negatively affecting the functional and structural performance of the pavements. Degradation of asphalt binders by volatilization and oxidation due to high production temperature occur during early stages of pavement life and are known as Short Term Aging (STA). Elevated temperatures and increased exposure time to elevated temperatures causes increased STA of asphalt.
Influence of aging on properties of polymer-modified asphalt
Construction and Building Materials, 2019
The carbon component in asphalt binder increased due to aging. The physical properties of the polymer-modified mixtures were much better than the reference mixture. The presence of polymeric additives can combat different detrimental effects of aging.
The effects of environmental aging on Colombian asphalts
Fuel, 2014
h i g h l i g h t s UV radiation produces either atomic ionization or free radicals within asphalts. Sara fractions change its composition due to aging process. Rheological behavior depends on chemical changes in asphalts by asphaltenes growth. MSCR test is a good tool to observe the behavior of deformation asphalt after aging. A period after STA and before LTA produces recovery on penetration, ductility and G * .