scholarly journals The Influence of Zero Shear Viscosity of TLA-Modified Binder and Mastic Composition on the Permanent Deformation Resistance of Mastic Asphalt Mixture

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5167
Author(s):  
Krzysztof Kołodziej ◽  
Lesław Bichajło ◽  
Tomasz Siwowski

Mastic asphalt (MA) has been particularly popular in recent years for bridge pavements due to many advantages such as easy application, good waterproofing properties, and high durability. However, the drawback of mastic asphalt in comparison to other asphalt mixtures is its lower resistance to permanent deformation. Trinidad Lake Asphalt (TLA) is often applied to make mastic asphalt resistant to permanent deformation. Practical experience demonstrates that serious failures may occur if MA pavement design and materials selection is not taken into account sufficiently. Therefore in this study, the influence of two parameters: zero shear viscosity (ZSV) of TLA-modified binder and mastic composition described by the filler–binder ratio, on the permanent deformation resistance of the MA mixture was evaluated. The primary purpose of determining the ZSV of the TLA-modified binders was to evaluate the rutting potential of the binders. The permanent deformation (rutting) resistance of the MA mixtures was evaluated based on static and dynamic indentation tests. The optimum content of TLA in the base bitumen and the optimum filler–binder ratio in the MA mixture were obtained based on multiple performance evaluations for modified binder, mastic and MA mixtures, i.e., 20% and 4.0, respectively.

Author(s):  
Ekarizan Shaffie ◽  
◽  
H.A. Rashid ◽  
Fiona Shiong ◽  
Ahmad Kamil Arshad ◽  
...  

Stone Mastic Asphalt (SMA) is a gap-graded hot mixture designed to provide higher resistance towards permanent deformation and rutting potential by 30% to 40% more than dense-graded asphalt, due to its stable aggregate skeleton structure. However, compared to other types of hot mix asphalt, SMA unfortunately has some shortcomings in term of its susceptibility towards moisture-induced damage due to its structure and excessive bitumen content in the composition. This research aims to assess the performance of a SMA mixture with steel fiber by enhancing overall stability, abrasion resistance, and, most importantly, moisture susceptibility. This study involved the incorporation of various steel fiber proportions of 0%, 0.3%, 0.5% and 0.7% by the total weight of mixture. The steel fiber modified SMA was made up of 6.0% PEN 60/70 bitumen content. The performance of SMA were evaluated through Marshall stability and flow test, Cantabro loss test and indirect tensile strength test. The results obtained from the testing showed that the incorporation of steel fiber is significantly effective to enhance the resistance towards moisture damage, while increasing the stability and reducing the abrasion loss of SMA mixture, compared to conventional mixture. Overall, it can be concluded that the addition of steel fiber in asphalt mixture specifically SMA, has improved the mechanical performance in the application of asphalt pavement with the optimum steel fiber proportion of 0.3% by the weight of mixture. The developed models between the independent variables and responses demonstrated high levels of correlation. The study found that Response Surface Methodology (RSM) is an effective statistical method for providing an appropriate empirical model for relating parameters and predicting the optimum performance of an asphaltic mixture to reduce flexible pavement failure.


2016 ◽  
Vol 16 ◽  
pp. 69-81 ◽  
Author(s):  
Muhammad Karami ◽  
Ainalem Nega ◽  
Ahdyeh Mosadegh ◽  
Hamid Nikraz

The main objective this study is to evaluate the permanent deformation of buton rock asphalt (BRA) modified asphalt paving mixtures using dynamic creep test so that long term deformation behavior of asphalt mixtures can be characterized. The dynamic creep test was conducted on unmodified and BRA modified asphalt mixture using UTM25 machine. Asphalt cement of C170 from a regional supplier in Western Australia was used as the base asphalt binder for unmodified asphalt mixture; and BRA modified asphalt mixtures were made by substituting the base asphalt with 10, 20, and 30% (by weight of total asphalt binder) natural binder continuing granular BRA modified binder. The granular (pellets) BRA modified binder with a diameter of 7-10 mm was produced and extracted according the Australia Standard. Crushed granite was taken from a local quarry of the region; and dense graded for both unmodified and BRA modified asphalt mixture with the nominal size of 10 mm was used. The results of this analysis showed that BRA modified had a good performance as compared with unmodified asphalt mixtures, and increase in the content modified binder to 10%, 20%, and 30% resulted in decrease of the total permanent strain.


Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2532
Author(s):  
Krzysztof Kołodziej ◽  
Lesław Bichajło ◽  
Tomasz Siwowski

The application of various modifiers has emerged in recent years to improve conventional petroleum-based bitumen properties. The natural asphalt called Trinidad Lake Asphalt (TLA) has been applied very often due to its consistent properties, high viscosity and density, and superior rheological properties, and effective blending with other bitumen. However, most studies on TLA-modified binders always focused on physical and rheological properties in the original (unaged) condition, but the details about aging properties are often neglected. This study aimed to investigate the effect of short-term aging on the physical and rheological characteristics of the 35/50 base bitumen modified by the addition of two different TLA contents. The conventional physical tests and dynamic shear rheological tests were undertaken before and after aging to measure the penetration and softening point, complex shear modulus, and phase angle of the modified binders, as well as to calculate the zero shear viscosity using the Cross model fitting procedure. Based on the results of the above-mentioned comprehensive testing, the effect of aging on TLA-modified binder properties was evaluated using aging indices, as well as a direct comparison of results. The tests revealed that the short-term aging of TLA-modified binders did not worsen or reduce the pavement resistance to permanent deformation or the load-bearing capacity of the asphalt mixture.


2019 ◽  
Vol 26 (1) ◽  
pp. 379-387
Author(s):  
Iuri S. Bessa ◽  
Márcia M. Takahashi ◽  
Kamilla L. Vasconcelos ◽  
Liedi L. B. Bernucci

AbstractThe addition of polymers on asphalt binders aims to enhance their performance, especially at high temperatures, which correspond to rutting resistance. The Superpave rutting parameter (|G*|/sinδ) has been considered to be inadequate to characterize the performance of modified materials, therefore the Multiple Stress Creep and Recovery (MSCR) test was developed, providing the parameter non-recoverable compliance (Jnr). This research has the main objective of correlating asphalt binders performance-based characterization with rutting resistance of asphalt mixtures, and presents results obtained for one conventional (50/70 penetration grade) and two modified asphalt binders (2.1% RET and 1.9% RET) regarding their rheological characteristics. With the use of the dynamic shear rheometer (DSR), master curves and MSCR results were obtained for the three binders. In addition, permanent deformation tests were performed on the asphalt mixtures by means of laboratory traffic simulation. The rutting characterization indicated higher permanent deformation resistance for the modified binders for the asphalt binder and the asphalt mixture testing. The main conclusions were that the use of modified binder reduced in approximately 50% the Jnr values and the rut depth; also, the asphalt binders’ characteristics were able to predict the asphalt mixtures rutting resistance.


Author(s):  
Ramadan Salim ◽  
Akshay Gundla ◽  
Ali Zalghout ◽  
B. Shane Underwood ◽  
Kamil E. Kaloush

The selection and specification of asphalt binder is one of the factors that ultimately affect the long-term performance of asphalt pavements. Many agencies currently follow AASHTO M320 for their binder specifications, where the ratio of dynamic modulus to the sine of the phase angle, | G*|/sin δ, is the binder rutting parameter. However, an alternative now exists, AASHTO M332, which uses the non-recovered creep compliance, J nr , for this purpose. In this paper, the relative merits of these two parameters are compared using experimental results from 21 different asphalt mixtures from Arizona. The rutting parameters according to AASHTO M332 and M320 were determined for each of the binders in these mixtures and, for each mixture, two rutting performance tests were conducted: Hamburg wheel tracking test and repeated load permanent deformation test. The two binder rutting parameters demonstrated very high correlation to one another for non-polymer modified asphalts, but inconsistent correlation for polymer modified asphalts. Both Hamburg wheel tracking tests and repeated load permanent deformation tests showed positive correlations to both | G*|/sin δ and Jnr. It was concluded that, while both parameters showed good correlation, the Jnr of the binder relates better to mixture rutting than does | G*|/sin δ. Considering the results in this study, it is believed that Jnr is a slightly better rutting parameter for binder specifications.


1988 ◽  
Vol 61 (5) ◽  
pp. 812-827 ◽  
Author(s):  
Ramesh R. Rahalkar ◽  
Henry Tang

Abstract Based upon the Doi-Edwards theory, a simple expression has been obtained for zero-shear viscosity in terms of the plateau modulus and the crossover frequency. There are no adjustable parameters in the expression. The model is in very good agreement with the zero-shear viscosity values for linear polybutadienes, the typical discrepancy being ∼5–10%. If the model can be validated for other linear amorphous polymers, it may become possible to estimate the zero-shear viscosity by measuring a single Theological parameter (the crossover frequency).


Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2116
Author(s):  
Yue Xiao ◽  
Limin Tang ◽  
Jiawei Xie

There are great uncertainties in road design parameters, and the traditional point numerical calculation results cannot reflect the complexity of the actual project well. Additionally, the calculation method of road design theory based on interval analysis is more difficult in the use of uncertain design parameters. In order to simplify the calculation process of the interval parameters in the road design theory, the asphalt pavement design is taken as the analysis object, and the permanent deformation of the asphalt mixture is simplified by combining the interval analysis theory. Considering the uncertainty of the design parameters, the data with boundaries but uncertain size are expressed in intervals, and then the interval calculation formula for the permanent deformation of the asphalt mixture is derived, and the interval results are obtained. In order to avoid the dependence of interval calculation on the computer code, according to the interval calculation rule, the interval calculation method with the upper and lower end point values as point operations is proposed. In order to overcome the contradiction between interval expansion results and engineering applications, by splitting the multi-interval variable formulas, the interval variable weights are reasonably given, and the synthesis of each single interval result realizes a simplified calculation based on interval variable weight assignment. The analysis results show that the interval calculation method based on the point operation rule is accurate and reliable, and the simplified method based on the interval variable weight assignment is effective and feasible. The simplified interval calculation method proposed in this paper provides a reference for the interval application of road design theory.


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