scholarly journals Fatigue Resistance Characterization of Warm Asphalt Rubber by Multiple Approaches

2018 ◽  
Vol 8 (9) ◽  
pp. 1495 ◽  
Author(s):  
Jiangmiao Yu ◽  
Xianshu Yu ◽  
Zheming Gao ◽  
Feng Guo ◽  
Duanyi Wang ◽  
...  
Keyword(s):  
Fatigue Test ◽  
Fatigue Resistance ◽  
Crumb Rubber ◽  
Waste Recycling ◽  
Fatigue Performance ◽  
Four Point Bending ◽  
Asphalt Rubber ◽  
Shear Fatigue ◽  
Tensile Fatigue ◽  
Indirect Tensile

Warm asphalt rubber (WAR) mixture is a sustainable paving material with advantages including waste recycling and noise reducing. A comprehensive understanding of the fatigue performance of WAR specimens is helpful to its wide application. However, research on evaluating the fatigue performance of WAR binder and mixtures is very limited. This paper applies five fatigue analysis approaches to evaluate the fatigue life of WAR samples with three different warm mix asphalt (WMA) additives. The conventional G*sinδ, linear amplitude sweep (LAS), indirect tensile fatigue test (ITFT), and four-point bending beam (4PB) test were conducted based on available standards. In addition, a novel shear fatigue test was performed on WAR mortars. Test results indicated that the incorporation of crumb rubber has a significantly positive effect on fatigue resistance. WAR with chemical and foaming additives exhibited a poorer performance than asphalt rubber (AR), but their fatigue performance was still greatly superior to the non-rubberized samples. Finally, LAS as well as mortar shear fatigue and 4PB tests provided the same prediction of fatigue resistance, while the results of G*sinδ and the ITFT were inconsistent. It is recommended to use LAS, the mortar shear fatigue test, and the 4PB test for the fatigue resistance evaluation of rubberized specimens. The validation of the findings with more materials and field performances is recommended.

Evaluation and Validation of Fatigue Testing Methods for Rubberized Bituminous Specimens

2019 ◽  
Vol 2673 (8) ◽  
pp. 603-610 ◽  
Author(s):  
Huayang Yu ◽  
Zihan Zhu ◽  
Duanyi Wang
Keyword(s):  
Fatigue Test ◽  
Fatigue Testing ◽  
Fatigue Behavior ◽  
Crumb Rubber ◽  
Fatigue Performance ◽  
Organic Chemical ◽  
Poor Correlation ◽  
Test Results ◽  
Asphalt Rubber ◽  
Shear Fatigue

Several fatigue evaluation methods are available to evaluate the durability of bituminous materials. In some cases, the test results may provide poor correlation with the true fatigue performance, especially when additives with complicated components are incorporated. This study aims to characterize the fatigue behavior of different warm asphalt rubber (WAR) specimens modified by both crumb rubber and warm mix asphalt (WMA) additives, and to validate the feasibility of binder and mortar fatigue tests on WAR. Three WARs with organic, chemical, and foaming additives were prepared. G*sin δ and liner amplitude sweep (LAS) tests (on both binders and liquid phases), and the shear fatigue test (on mortars) were performed. The four-point bending beam (4PB) test was used as reference to validate results of binder, liquid phase, and mortar tests. Test results indicated that the fatigue performance of virgin bitumen is obviously improved by crumb rubber. The selected organic additive contributes to superior fatigue resistance, whereas WARs with foaming and chemical WMA modifiers performed more poorly than asphalt rubber in relation to fatigue, but still much better that the non-rubberized samples. Finally, it is noted that for the rubberized bituminous specimens, LAS evaluation for asphalt binder and the shear fatigue test for asphalt mortar provide same prediction as the 4PB test, whereas other tests give inconsistent results. Therefore, it is suggested to use the 4PB test on mixture, the LAS test on binder, and the shear fatigue test on mortar for fatigue performance characterization of bituminous specimens containing crumb rubber particles. Further validation of the above findings on field specimens is suggested.

scholarly journals Evaluation of Fatigue Life of CRM-Reinforced SMA and Its Relationship to Dynamic Stiffness

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Nuha Salim Mashaan ◽  
Mohamed Rehan Karim ◽  
Mahrez Abdel Aziz ◽  
Mohd Rasdan Ibrahim ◽  
Herda Yati Katman ◽  
...  
Keyword(s):  
Fatigue Life ◽  
Fatigue Test ◽  
Resilient Modulus ◽  
Dynamic Stiffness ◽  
Asphalt Mixture ◽  
Fatigue Cracking ◽  
Crumb Rubber ◽  
Fatigue Properties ◽  
Tensile Fatigue ◽  
Indirect Tensile

Fatigue cracking is an essential problem of asphalt concrete that contributes to pavement damage. Although stone matrix asphalt (SMA) has significantly provided resistance to rutting failure, its resistance to fatigue failure is yet to be fully addressed. The aim of this study is to evaluate the effect of crumb rubber modifier (CRM) on stiffness and fatigue properties of SMA mixtures at optimum binder content, using four different modification levels, namely, 6%, 8%, 10%, and 12% CRM by weight of the bitumen. The testing undertaken on the asphalt mix comprises the dynamic stiffness (indirect tensile test), dynamic creep (repeated load creep), and fatigue test (indirect tensile fatigue test) at temperature of 25°C. The indirect tensile fatigue test was conducted at three different stress levels (200, 300, and 400 kPa). Experimental results indicate that CRM-reinforced SMA mixtures exhibit significantly higher fatigue life compared to the mixtures without CRM. Further, higher correlation coefficient was obtained between the fatigue life and resilient modulus as compared to permanent strain; thus resilient modulus might be a more reliable indicator in evaluating the fatigue life of asphalt mixture.

scholarly journals Influence of F-T Synthetic Wax on Asphalt Concrete Permanent Deformation

2013 ◽  
Vol 59 (3) ◽  
pp. 295-312
Author(s):  
M. Iwański ◽  
G. Mazurek
Keyword(s):  
Fatigue Life ◽  
Fatigue Test ◽  
Asphalt Concrete ◽  
Permanent Deformation ◽  
Positive Influence ◽  
Test Results ◽  
Fischer Tropsch ◽  
Stiffness Modulus ◽  
Tensile Fatigue ◽  
Indirect Tensile

Abstract The paper presents the results of the study of the effect of a Fischer-Tropsch (F-T) synthetic wax on the resistance to permanent deformation of the AC 11S asphalt concrete. The synthetic wax was dosed at 1.5%, 2.5% and 3.5% by weight of bitumen 35/50. The compaction temperatures were 115°C, 130°C and 145°C. The criteria adopted for measuring the resistance to permanent deformation included the following parameters: stiffness modulus at 2, 10 and 20°C, permanent deformation (RTS), fatigue life determined using the indirect tensile fatigue test (ITFT) and resistance to rutting (WTSAIR, PRDAIR). The test results confirmed the positive influence of F-T synthetic wax on enhancing the permanent deformation resistance of asphalt concrete placed at lower compaction temperatures compared to that of standard asphalt concrete compacted at 140°C.

scholarly journals Laboratory Study on the Fatigue Resistance of Asphaltic Concrete Containing Titanium Dioxide

2018 ◽  
Vol 34 ◽  
pp. 01021
Author(s):  
Rosnawati Buhari ◽  
Mohd Ezree Abdullah ◽  
Mohd Khairul Ahmad ◽  
Saiful Azhar Tajudin ◽  
Siti Khatijah Abu Bakar
Keyword(s):  
Titanium Dioxide ◽  
Asphalt Mixture ◽  
Performance Testing ◽  
Fatigue Performance ◽  
Fatigue Properties ◽  
Modified Asphalt ◽  
Tensile Fatigue ◽  
Asphalt Mix ◽  
Rotational Viscosity ◽  
Indirect Tensile

This study aims to evaluate the fatigue performance of modified asphalt mixture using Indirect Tensile Fatigue Test. Titanium Dioxide (TiO2) powder in a form of rutile was used for producing asphalt concrete with lower mixing and compaction temperature compared to conventional hot mix asphalt without reducing its physical and mechanical also resistance to fatigue. The characteristic of the asphalt and modified asphalt was evaluated using penetration test, softening test and rotational viscosity test. Titanium dioxide of 2%, 4%, 6%, 8% and 10% by weight of asphalt has been incorporated into unaged 80/100 asphalt mix in order to improvise its performance and to fulfill the objectives of this experimental study. As a result, TiO2 as an additive is potential to decrease the penetration and increasing the softening point of the asphalt. In terms of fatigue performance testing, addition TiO2 additive does help in improving the fatigue properties as it shows greater result than the control asphalt. In conclusion, TiO2 is great in improving fatigue properties.

scholarly journals Discrete Element Analysis of Indirect Tensile Fatigue Test of Asphalt Mixture

2019 ◽  
Vol 9 (2) ◽  
pp. 327 ◽  
Author(s):  
Xuelian Li ◽  
Xinchao Lv ◽  
Xueying Liu ◽  
Junhong Ye
Keyword(s):  
Fatigue Test ◽  
Asphalt Mixture ◽  
Discrete Element ◽  
Particle Flow Code ◽  
Displacement Curve ◽  
Distribution Characteristics ◽  
Load Curve ◽  
Element Analysis ◽  
Tensile Fatigue ◽  
Indirect Tensile

In order to investigate the damage to microstructure and some other micromechanical responses during a fatigue test on asphalt mixture, Particle Flow Code (PFC) was used to reconstruct a two-dimensional discrete element model of asphalt mixture, based on computed tomography (CT) images and image-processing techniques. The indirect tensile fatigue test of asphalt mixture was simulated with this image-based microstructural model, and verified in the laboratory. It was found that there were four stages during the fatigue failure: no crack, crack initiation, crack developing, and interconnected crack. Cracks mainly developed between the aggregate and asphalt mortar, near the loading axis. The corresponding stages of failure, the developing trend and the distribution characteristics of the cracks matched well with those in the laboratory test. Furthermore, the trends of both the time-load curve and time-displacement curve from the simulation test were also consistent with those from the experimental test. In short, the distribution characteristics of cracks and internal forces of asphalt mixture show that it is feasible to simulate the fatigue performance of the asphalt mixture by a discrete element method (DEM).

scholarly journals Preliminary Studies to Use Textile Fibers Obtained from Recycled Tires to Reinforce Asphalt Mixtures

2018 ◽  
Vol 7 (2) ◽  
pp. 14-30
Author(s):  
Jorge C. Pais ◽  
António Ferreira ◽  
Caio Santos ◽  
Paulo Pereira ◽  
Davide Lo Presti
Keyword(s):  
Asphalt Mixture ◽  
Tensile Tests ◽  
Crumb Rubber ◽  
Asphalt Mixtures ◽  
Asphalt Pavements ◽  
Valuable Resource ◽  
Scrap Tires ◽  
Textile Fibers ◽  
Asphalt Rubber ◽  
Indirect Tensile

Abstract The use of crumb rubber in the modification of asphalt has occurred because of the problems related to disposal of scrap tires. However, the use of scrap tires in asphalt pavements, known as asphalt rubber pavements, can minimize environmental impacts and maximize conservation of natural resources. The textile fibers from recycled tires are typically disposed of in landfills or used in energetic valorization, but similar to other fibers, they can be used as a valuable resource in the reinforcement of engineering materials such as asphalt mixtures. Thus, this work aims at studying the use of textile fibers recycled from ground tires in the reinforcement of conventional asphalt mixtures. The application of textile fibers from ground tires was evaluated through laboratory tests on specimens extracted from slabs produced in the laboratory. Indirect tensile tests were performed on a series of nine asphalt mixtures with different fiber and asphalt contents and compared with a conventional mixture. The results obtained from a 50/70 pen asphalt were used to define three asphalt mixture configurations to be used with 35/50 pen asphalt. The results indicate that the textile fibers recycled from used tires can be a valuable resource in the reinforcement of asphalt mixtures.

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