scispace - formally typeset
Search or ask a question
Journal ArticleDOI

Fatigue performance of long-term aged crumb rubber modified bitumen containing warm-mix additives

TL;DR: In this paper, the effects of crumb rubber modifier (CRM) content (5, 10, 15% and 22% by weight of base bitumen) and warm-mix additives on the binder fatigue performance were investigated.
About: This article is published in Construction and Building Materials.The article was published on 2020-04-10 and is currently open access. It has received 49 citations till now. The article focuses on the topics: Rubberized asphalt & Crumb rubber.
Citations
More filters
Journal ArticleDOI
TL;DR: In this article, the effects of laboratory short-term and long-term aging on the chemistry and rheology of crumb rubber modified bitumen (CRMB) was investigated.
Abstract: Aging during construction and in-service substantially changes the chemical composition and physical properties of bitumen thereof influences the performance of asphalt pavements. The modification of bitumen by crumb rubber modifier (CRM) significantly increases the complexity of the aging mechanism and is expected to improve the aging resistance of bitumen. This study aims to investigate the effects of laboratory short-term and long-term aging on the chemistry and rheology of crumb rubber modified bitumen (CRMB). Neat bitumen and CRMB with four different CRM contents were studied. Fourier transform infrared spectroscopy and dynamic shear rheometer were employed to measure the change in the chemical composition and rheological properties of binders at different aging states. Bitumen hardening, which was rheologically revealed by the frequency sweep and multiple creep recovery test results, was also reflected in the growth of carbonyl and sulfoxide functional groups. In addition, the aliphaticity and aromaticity indices of binders before and after aging were also investigated. CRMB binders showed improved aging resistance compared to neat bitumen as reflected by the decreased carbonyl and sulfoxide indices as well as the lower change in rheological parameters. Higher resistance against aging was achieved when increasing the CRM content. The results also highlight the correlation between chemistry and rheology of bitumen. Among six selected mechanical parameters of binder, the non-recoverable creep compliance and percent recovery show better correlations with the combined chemical aging index (sum of carbonyl and sulfoxide indices) than the parameters derived from the linear viscoelastic region.

66 citations


Cites background from "Fatigue performance of long-term ag..."

  • ...environmental and traffic loadings resulting in performance deterioration of asphalt pavements [9, 10]....

    [...]

Journal ArticleDOI
TL;DR: In this paper, the authors investigated the role of crumb rubber modifier (CRM) absorption in improving the aging resistance of asphalt rubber and warm asphalt rubber (WAR) binders and concluded that sufficient rubber absorption should be emphasized during the production of AR for better aging resistance.

43 citations

Journal ArticleDOI
01 Oct 2022-Polymers
TL;DR: In this paper , the mechanical and rheological properties of a 60/70 penetration grade asphalt binder modified with Crumb Rubber (CR) and WMA chemical additives (Evotherm M1 and Iterlow T) were investigated.
Abstract: Crumb rubber (CR) is one of the materials most widely used in the road infrastructure industry due to its mechanical and environmental benefits as an asphalt binder modifier. Nonetheless, CR decreases the workability of mixes by increasing the viscosity of the binder, leading to an increase in the production temperatures of asphalt mixes. However, warm mix technologies can reduce the temperature demand associated with these processes. The preceding explains the growing interest in producing rubberised asphalt binders incorporating warm mix asphalt (WMA) additives. In this research, the mechanical and rheological properties of a 60/70 penetration grade asphalt binder modified with CR (at a dosage of 15, 18 and 21% by the wet process) and WMA chemical additives (Evotherm M1 and Iterlow T) were investigated. Laboratory tests included penetration, softening point, rotational viscosity, frequency sweep through dynamic shear rheometer (DSR), and multiple stress creep recovery (MSCR) tests. The results indicate that CR increases the stiffness of the asphalt binder, which is reflected in a lower penetration grade and improved softening point. It also improves its rutting resistance but decreases fatigue performance. Furthermore, it has been shown that under the conditions studied, the higher the CR content, the more elevated the degree of stiffness and performance of the asphalt binder. On the other hand, WMA technology decreases asphalt stiffness and performance at high temperatures.

31 citations

01 Jan 2018
TL;DR: In this article, the effects of warm-mix asphalt (WMA) additives, organic type and chemical type, on the rheological properties and chemical internal structure of base asphalt and crumb rubber modified asphalt (CRMA) were investigated.
Abstract: The microstructure and chemical composition of asphalt binders have a significant effect on their rheological properties and, therefore, their performance as road paving binders. This study aims to investigate the effects of warm-mix asphalt (WMA) additives, organic type and chemical type, on the rheological properties and chemical internal structure of base asphalt and crumb rubber modified asphalt (CRMA). A set of dynamic shear rheometer (DSR) tests was conducted to obtain the rheological parameters (e.g., complex viscosity, complex modulus, phase angle) of asphalt binders. The flow activation energy was calculated from Arrhenius equation based on viscosity data to rank the thermal susceptibility. Black diagrams and master curves of complex modulus and phase angle were utilized to analyze the rheological properties. The molecular weight distributions of asphalt binders were inverted from the phase angle master curve to evaluate the molecular weight characteristics. It was found that the the addition of crumb rubber into base asphalt improves the rheological properties of enhanced modulus and elasticity. Organic and chemical types of WMA additives have different chemo-physical effects on both base asphalt and CRMA. Phase angle inversion method provides a powerful tool to monitor the molecular structure change and, therefore, the chemo-physical interactions of asphalt binders induced by modifications. Finally, there is a good correlation between flow activation energy and molecular weight.

29 citations

Journal ArticleDOI
Yanqiu Bi1, Shuaifeng Wu1, Jianzhong Pei1, Yong Wen1, Rui Li1 
TL;DR: In this article, the changes of rheological indices before and after asphalt aging were observed and the sensitivity of different indices to aging was compared with each other, and the relationships among rheology indices were discussed.

22 citations

References
More filters
Journal ArticleDOI
TL;DR: A literature review on the existing technologies and specifications related to the production, handling and storage of RTR-MBs and on their current applications within road asphalt mixtures is presented in this article.

640 citations

01 Jan 2011
TL;DR: In this article, a laboratory study was conducted to evaluate if there was any potential relationship between asphalt binder properties and non-load related cracking, as part of a research project involving airfield asphalt pavements.
Abstract: A laboratory study was conducted to evaluate if there was any potential relationship between asphalt binder properties and non-load related cracking, as part of a research project involving airfield asphalt pavements. The objective of the research was to identify one or more parameters that could be easily determined by testing that would allow an airport manager to monitor the loss of durability experienced with aging and to use the information to evaluate when the airfield asphalt pavement would need preventative maintenance to minimize the effects of non-load associated cracking. Three asphalt binders were selected representing different expected aging characteristics, in the laboratory study. Testing was conducted on asphalt binders in their unaged condition, as well as on asphalt binders that had undergone long-term aging in the Pressure Aging Vessel (PAV) at 100C and 2.1 MPa pressure for 20, 40, and 80 hours. The purpose of the longer PAV aging times was not to correlate with any expected service life, but simply to create a more highly-aged sample. Past research suggested some relationship between ductility (conducted at an intermediate temperature) and the durability of an asphalt pavement. Using ductility as the hypothesized property related to flexibility, two parameters were identified that related well to ductility and the expected loss of flexibility with aging. The first is a parameter suggested by other researchers—G′/(η′/G′)—as determined using the Dynamic Shear Rheometer (DSR). The second is a parameter that quantifies the difference in continuous grade temperature for stiffness and relaxation properties—referred to in the paper as ΔTc. In both cases, the parameters appear to quantify the loss of relaxation properties as an asphalt binder ages. Limited field testing from three general aviation airports generally confirmed the findings from the lab study, with the newer pavements having values of G′/(η′/G′) and ΔTc that displayed more flexibility and less aging than the older pavements. Based on the study results, values were determined for both parameters that could provide an indication of a loss of durability that could result in a greater risk of non-load associated cracking.

268 citations


"Fatigue performance of long-term ag..." refers background in this paper

  • ...A higher value of this parameter indicates increased brittleness or decreased ductility of binders [20]....

    [...]

Journal ArticleDOI
TL;DR: The linear amplitude sweep (LAS) test as discussed by the authors uses cyclic loading with systematically increasing load amplitudes to accelerate damage and provides sufficient data for analysis in less than 30 min.
Abstract: Current asphalt binder specifications lack the ability to characterize asphalt binder damage resistance to fatigue loading. Multiple accelerated testing procedures that attempt to efficiently and accurately characterize the contribution of asphalt binders to mixture fatigue are under investigation. One of these tests, which has received significant acceptance by experts and has been submitted as a draft AASHTO standard, is the linear amplitude sweep (LAS) test. This procedure uses viscoelastic continuum damage mechanics to predict binder fatigue life as a function of strain in the pavement. The LAS test uses cyclic loading with systematically increasing load amplitudes to accelerate damage and provides sufficient data for analysis in less than 30 min. Although results of the current LAS testing protocol are promising, the time and the complex numerical procedures required for the analysis have raised concern. In addition, insufficient damage accumulation was observed when the strain amplitudes proposed in...

267 citations


"Fatigue performance of long-term ag..." refers background in this paper

  • ...It was found that the binder fatigue life predicted from LAS test results showed a promising correlation with the measured crack length in actual asphalt pavements of the Long-Term Pavement Preservation (LTPP) program [28]....

    [...]

01 Jan 1999
TL;DR: In this paper, the role of non-linear viscoelastic properties of asphalt binders in mixture response was investigated and the results indicated that linear properties are not good indicators of mixture response.
Abstract: A study was conducted to relate linear visco-elastic properties of asphalt binders of the same PG-Grade to the rheological properties of asphalt mixtures of same aggregate source, gradation, and volumetric proportions. The only variable was the type of modifier used in the production of the binder. Results indicated that linear properties are not good indicators of mixture response. The study was expanded to evaluate the role of non-linear viscoelastic properties in mixture response. The results collected indicate that modified and un-modified asphalt binders vary significantly in the non-linear behavior. The non-linear study was expanded to include fatigue performance of binders at various strain levels in the linear and non-linear range. The paper presents a parametric study showing factors that influence strain dependency of asphalt binders of a wide variety of chemical composition and modification techniques. The results of fatigue testing of the binders are also presented to show factors that influence fatigue behavior. This paper is intended to stimulate the research on the non-linear behavior of binders and to suggest that non-linear properties are essential for effective estimation of the role of binders in mixture behavior.

199 citations


"Fatigue performance of long-term ag..." refers background in this paper

  • ...A major drawback of this fatigue parameter is that it cannot really account for real damage since it is determined within the LVE range of the binder where the nonlinear response is not captured [17]....

    [...]

Journal ArticleDOI
TL;DR: In this paper, a time sweep using the dynamic shear rheometer (DSR) has been proposed as an alternative test method for developing load-associated fatigue information for asphalt binders.
Abstract: The original SuperPave asphalt binder specification criterion for fatigue, G* sin δ, has received considerable criticism. Recently, a time sweep using the dynamic shear rheometer (DSR) has been proposed as an alternative test method for developing load-associated fatigue information for asphalt binders. This proposed test method is examined with respect to a phenomenon called edge fracture. Edge fracture is reported in the literature for steady state and oscillatory flow in DSR, but it has not been reported for asphalt binders. The modulus, when plotted versus number of cycles generated in a time sweep test, has the appearance typical of fatigue behavior; however, the actual response of the material depends markedly on the initial modulus of the material. The development of the modulus with repeated shearing is described with respect to flow of the asphalt binder at its circumference. The data are examined with respect to their validity as a measure of fatigue, and recommendations with respect to the use ...

197 citations


Additional excerpts

  • ..., are proposed for fatigue analysis [22,23]....

    [...]