Evaluation of field aging effects on asphalt binder properties

Many factors affecting pavement performance include variations in binder composition and environmental conditions during asphalt mixture production. Hence, predicting pavement performance is a difficult task. This paper aims to investigate the effects of short term aging on binder viscosity at high temperature. In order to predict the effects of short term aging on the asphalt binder viscosity at high temperatures, a Response Surface Method was performed on the Rotational Viscometer test results. An experimental matrix was planned based on the central composite design for aging duration and test temperature. The test results showed that aging increased the binder viscosity, while increasing test temperature decreased the corresponding value. However, aging effects differ and depend on binder types, test temperatures and aging conditions. It was also found that the Response Surface Method is a fast, effective and reliable method to predict the effects of aging on binder viscosity behaviour at high temperatures.

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Recommended asphalt binder fatigue performance specification from full-scale accelerated pavement tests considering aging effects

Advances in Pavement Design through Full-scale Accelerated Pavement Testing ◽

10.1201/b13000-54 ◽

2012 ◽

pp. 433-441 ◽

Cited By ~ 2

Author(s):

N Gibson ◽

X Qi ◽

A Andriescu ◽

A Copeland

Keyword(s):

Asphalt Binder ◽

Full Scale ◽

Fatigue Performance ◽

Aging Effects ◽

Performance Specification

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Modelling short-term aging of asphalt binders using the rolling thin film oven test

Canadian Journal of Civil Engineering ◽

10.1139/l01-086 ◽

2002 ◽

Vol 29 (1) ◽

pp. 135-144 ◽

Cited By ~ 23

Author(s):

Ahmed Shalaby

Keyword(s):

Thin Film ◽

Shear Modulus ◽

Phase Angle ◽

Asphalt Binder ◽

Temperature Shift ◽

Test Methods ◽

Asphalt Binders ◽

Aging Effects ◽

Short Term ◽

Oven Test

Simulation of short-term aging of asphalt binders is a widely used procedure in asphalt binder characterization for predicting the binder response to plant mixing and paving under controlled laboratory conditions. There are two laboratory test methods for evaluating the short-term aging of asphalt binders: (i) a method using rotating pans filled with a thin asphalt film termed thin film oven test (TFOT) and (ii) a method using rolling cylindrical asphalt containers termed rolling thin film oven test (RTFOT). In this paper, an attempt is made to develop generalized models for short-term aging effects using the RTFOT aging time as a benchmark. Six binder types representing two PG grades and three source suppliers are conditioned to varying levels of RTFOT aging and tested using the dynamic shear rheometer (DSR). Aging effects are modelled using independent temperature shift models for the shear modulus and phase angle. The paper discusses the sources of errors in producing generalized models and some potential applications of aging models. The research revealed that it is possible to develop and implement such models for unmodified binders.Key words: asphalt, aging, RTFOT, DSR, binder rheology, shear modulus, phase angle.

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Short Term and Long Term Aging Effects of Asphalt Binder Modified with Montmorillonite

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.594-595.996 ◽

2013 ◽

Vol 594-595 ◽

pp. 996-1002 ◽

Cited By ~ 17

Author(s):

Mohd Ezree Abdullah ◽

Kemas Ahmad Zamhari ◽

Rosnawati Buhari ◽

Mohd Nafarizal Nayan ◽

Hainin Mohd Rosli

Keyword(s):

Aging Process ◽

Asphalt Binder ◽

Mechanical Analysis ◽

Aging Effects ◽

Short Term ◽

Rotational Viscometer ◽

Before And After ◽

Pavement Construction ◽

Modified Binder

Nowadays, most of asphalt used in pavement construction is produced from petrochemicals through refining process of crude oil. When evolves with time, asphalt become stiffer and brittle due aging process. In this paper, the rheological effect of short-term and long-term oxidative ageing of asphalt binder modified with montmorillonite (MMT) was studied using SuperpaveTM rotational viscometer (RV), dynamic shear rheometer (DSR) and Fourier transform infrared (FTIR) instruments. The results indicate the addition of MMT increased the viscosity. Based on dynamic mechanical analysis with DSR, MMT modified binder has a potential to increase rutting and fatigue resistance. In terms of FTIR test, it appears that the chemical bonding had changed in the asphalt binder before and after RTFO and PAV aging which suggest that the additional of MMT could delay the aging process.

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Effects of Aging on the Subcortical Encoding of Stop Consonants

American Journal of Audiology ◽

10.1044/2020_aja-19-00044 ◽

2020 ◽

Vol 29 (3) ◽

pp. 391-403

Author(s):

Dania Rishiq ◽

Ashley Harkrider ◽

Cary Springer ◽

Mark Hedrick

Keyword(s):

Older Adults ◽

Repeated Measures ◽

Mixed Model ◽

Auditory Brainstem ◽

Auditory Brainstem Responses ◽

Aging Effects ◽

Formant Frequency ◽

Place Of Articulation ◽

Second Formant ◽

Effects Of Aging

Purpose The main purpose of this study was to evaluate aging effects on the predominantly subcortical (brainstem) encoding of the second-formant frequency transition, an essential acoustic cue for perceiving place of articulation. Method Synthetic consonant–vowel syllables varying in second-formant onset frequency (i.e., /ba/, /da/, and /ga/ stimuli) were used to elicit speech-evoked auditory brainstem responses (speech-ABRs) in 16 young adults ( M age = 21 years) and 11 older adults ( M age = 59 years). Repeated-measures mixed-model analyses of variance were performed on the latencies and amplitudes of the speech-ABR peaks. Fixed factors were phoneme (repeated measures on three levels: /b/ vs. /d/ vs. /g/) and age (two levels: young vs. older). Results Speech-ABR differences were observed between the two groups (young vs. older adults). Specifically, older listeners showed generalized amplitude reductions for onset and major peaks. Significant Phoneme × Group interactions were not observed. Conclusions Results showed aging effects in speech-ABR amplitudes that may reflect diminished subcortical encoding of consonants in older listeners. These aging effects were not phoneme dependent as observed using the statistical methods of this study.

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Age Differences in Eye Movements During Reading: Degenerative Problems or Compensatory Strategy?

European Psychologist ◽

10.1027/1016-9040/a000344 ◽

2019 ◽

Vol 24 (4) ◽

pp. 297-311

Author(s):

José David Moreno ◽

José A. León ◽

Lorena A. M. Arnal ◽

Juan Botella

Keyword(s):

Eye Movements ◽

Eye Movement ◽

Meta Analysis ◽

Age Groups ◽

Behavioral Changes ◽

Aging Effects ◽

Movement Data ◽

Sentence Reading ◽

The Difference ◽

Eye Movements During Reading

Abstract. We report the results of a meta-analysis of 22 experiments comparing the eye movement data obtained from young ( Mage = 21 years) and old ( Mage = 73 years) readers. The data included six eye movement measures (mean gaze duration, mean fixation duration, total sentence reading time, mean number of fixations, mean number of regressions, and mean length of progressive saccade eye movements). Estimates were obtained of the typified mean difference, d, between the age groups in all six measures. The results showed positive combined effect size estimates in favor of the young adult group (between 0.54 and 3.66 in all measures), although the difference for the mean number of fixations was not significant. Young adults make in a systematic way, shorter gazes, fewer regressions, and shorter saccadic movements during reading than older adults, and they also read faster. The meta-analysis results confirm statistically the most common patterns observed in previous research; therefore, eye movements seem to be a useful tool to measure behavioral changes due to the aging process. Moreover, these results do not allow us to discard either of the two main hypotheses assessed for explaining the observed aging effects, namely neural degenerative problems and the adoption of compensatory strategies.

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