scholarly journals Evaluating the Effects of High RAP Content and Rejuvenating Agents on Fatigue Performance of Fine Aggregate Matrix through DMA Flexural Bending Test

Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1508 ◽  
Author(s):  
Chenchen Zhang ◽  
Qi Ren ◽  
Zhendong Qian ◽  
Xudong Wang
Keyword(s):  
Fatigue Life ◽  
Phase Angle ◽  
Fatigue Resistance ◽  
Prediction Models ◽  
Asphalt Mixtures ◽  
Traffic Load ◽  
Bending Test ◽  
Fine Aggregate ◽  
Test Results ◽  
Fine Aggregate Matrix

High percentage reclaimed asphalt pavement (RAP) is prevailing in pavement engineering for its advantages in sustainability and environmental friendliness, however, its fatigue resistance remains a major concern. Fine aggregate matrix (FAM) is a crucial part in the fatigue resistance of asphalt mixtures with high RAP content. Hence, the linear amplitude sweep (LAS) test of FAM has been developed to study the fatigue resistance of asphalt mixtures. However, the torsional loading mode of the LAS test with a dynamic shear rheometer (DSR) is a limitation to simulate traffic load. In this paper, an alternative LAS test for FAM with high RAP content was proposed. Beam FAM specimens were tested using a dual-cantilever flexural loading fixture in a dynamic mechanical analyzer (DMA). To investigate the influence of RAP content and the rejuvenating agent (RA), four kinds of FAM mixes were tested with this method to study their fatigue resistance. The test results suggested that the repeatability of this alternative approach was reliable. A fatigue failure criterion based on maximum C × N was defined. Then, fatigue life prediction models based on viscoelastic continuum damage (VECD) analysis were established according to the LAS test results and validated by a strain-controlled time sweep (TS) test. It turned out that as RAP content increased, the modulus of FAM would be significantly raised, accompanied with a drop in the phase angle. The fatigue life of FAM would be greatly shortened when the RAP binder replacement rate reached 50%. Adding RA could considerably improve the dynamic properties of FAM mixes with high RAP content, resulting in a decrease in modulus, increase in phase angle and elongating fatigue life, but could not recover to the level of virgin binder.

scholarly journals Preparation and Mechanical-Fatigue Properties of Elastic Polyurethane Concrete Composites

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3839
Author(s):  
Zhen Jia ◽  
Dongzhe Jia ◽  
Quansheng Sun ◽  
Yanqi Wang ◽  
Hongjian Ding
Keyword(s):  
Fatigue Life ◽  
Fatigue Resistance ◽  
Building Materials ◽  
Prediction Models ◽  
Engineering Application ◽  
Tensile Tests ◽  
Fatigue Properties ◽  
Dissipated Energy ◽  
Fine Aggregate ◽  
Rubber Particles

In order to solve issues related to bridge girders, expansion devices and road surfaces, as well as other structures that are prone to fatigue failure, a kind of fatigue-resistant elastic polyurethane concrete (EPUC) was obtained by adding waste rubber particles (40 mesh with 10% fine aggregate volume replacement rate) to conventional engineering polyurethane concrete (PUC). Based on the preparation and properties of EPUC, its constitutive relation was proposed through compression and tensile tests; then, a scanning electron microscope (SEM), an atomic force microscope (AFM) and a 3D non-contact surface profilometer were used to study the failure morphology and micromechanisms of EPUC. On this basis, four-point bending fatigue tests of EPUC were carried out at different temperature levels (−20 °C, 0 °C, 20 °C) and different strain levels (400 με~1200 με). These were used to analyze the stiffness modulus, hysteresis angle and dissipated energy of EPUC, and our results outline the fatigue life prediction models of EPUC at different temperatures. The results show that the addition of rubber particles fills the interior of EPUC with tiny elastic structures and effectively optimizes the interface bonding between aggregate and polyurethane. In addition, EPUC has good mechanical properties and excellent fatigue resistance; the fatigue life of EPUC at a room temperature of 600 με can grow by more than two million times, and it also has a longer service life and reduced disease frequency, as well as fewer maintenance requirements. This paper will provide a theoretical and design basis for the fatigue resistance design and engineering application of building materials. Meanwhile, the new EPUC material has broad application potential in terms of roads, bridges and green buildings.

scholarly journals Fatigue Life Prediction of Rolling Bearings Based on Modified SWT Mean Stress Correction

2020 ◽  
Author(s):  
Aodi Yu ◽  
Hong-Zhong Huang ◽  
Yan-Feng Li ◽  
He Li ◽  
Ying Zeng
Keyword(s):  
Fatigue Life ◽  
Life Prediction ◽  
Stress Ratio ◽  
Prediction Models ◽  
Great Influence ◽  
Sensitivity Coefficient ◽  
Model Verification ◽  
Mean Stress ◽  
Test Results ◽  
Rolling Bearings

Abstract Mean stress has a great influence on fatigue life, commonly used stress-based life prediction models can only fit the test results of fatigue life under specific stress ratio or mean stress but cannot describe the effect of stress ratio or mean stress on fatigue life. Smith, Watson and Topper (SWT) proposed a simple mean stress correction criterion. However, the SWT model regards the sensitivity coefficient of all materials to mean stress as 0.5, which will lead to inaccurate predictions for materials with a sensitivity coefficient not equal to 0.5. In this paper, considering the sensitivity of different materials to mean stresses, compensation factor is introduced to modify the SWT model, and several sets of experimental data are used for model verification. Then, the proposed model is applied to fatigue life predictions of rolling bearings, and the results of proposed method are compared with test results to verify its accuracy.

scholarly journals Deformation Parameters and Fatigue of the Recycled Asphalt Mixtures

2015 ◽  
Vol 11 (2) ◽  
pp. 115-120
Author(s):  
Juraj Šrámek
Keyword(s):  
Complex Modulus ◽  
Permanent Deformation ◽  
Asphalt Mixtures ◽  
Test Method ◽  
Traffic Load ◽  
Bending Test ◽  
Recycled Asphalt ◽  
The Road ◽  
Dynamic Methods ◽  
Deformation Complex

Abstract The deformational properties of asphalt mixtures measured by dynamic methods and fatigue allow a design the road to suit the expected traffic load. Quality of mixtures is also expressed by the resistance to permanent deformation. Complex modulus of stiffness and fatigue can reliably characterize the proposed mixture of asphalt pavement. The complex modulus (E*) measurement of asphalt mixtures are carried out in laboratory of Department of Construction Management at University of Žilina by two-point bending test method on trapezoid-shaped samples. Today, the fatigue is verified on trapezoid-shaped samples and is assessed by proportional strain at 1 million cycles (ε6). The test equipment and software is used to evaluate fatigue and deformation characteristics.

Laboratory Investigate of the Effect of Fine Aggregates on Asphalt Mixture Materials

2011 ◽  
Vol 225-226 ◽  
pp. 577-580
Author(s):  
Yong Ye ◽  
Yi Zhou Cai
Keyword(s):  
Compressive Strength ◽  
Asphalt Mixture ◽  
Aggregate Size ◽  
Asphalt Mixtures ◽  
Fine Aggregate ◽  
Test Results ◽  
Creep Tests ◽  
Aggregate Gradation ◽  
Static Creep ◽  
Fine Aggregates

The objective of this study is to investigate and evaluate the effect of fine aggregates (aggregate size smaller than or equal to 2.36 mm) on the compressive strength and creep behavior of asphalt mixtures. The variables that are considered in the study include the sizes and gradations of fine aggregate. A kind of standant aggregate gradation and four kinds of reduced aggregate gradation mixture specimens are used. Uniaxial compression and static creep tests were realized at different loading conditions. The test results showed that the different fine aggregate sizes do not result in significant differences in compressive strength and creep values using the same percentage of fine aggregates (38.4%). Only the different gradations showed a little differences for mixtures made with different gradations but same aggregate size (between 2.36 and 1.18 mm).

Comparative evaluation of fatigue resistance of warm fine aggregate asphalt mixtures

2016 ◽  
Vol 109 ◽  
pp. 8-16 ◽  
Author(s):  
Mohammed Sadeq ◽  
Hussain Al-Khalid ◽  
Eyad Masad ◽  
Okan Sirin
Keyword(s):  
Fatigue Resistance ◽  
Comparative Evaluation ◽  
Asphalt Mixtures ◽  
Fine Aggregate

Performance of Asphalt Rejuvenators in Hot-Mix Asphalt Containing Recycled Asphalt Shingles

2017 ◽  
Vol 2633 (1) ◽  
pp. 108-116 ◽  
Author(s):  
Max A. Aguirre ◽  
Marwa M. Hassan ◽  
Sharareh Shirzad ◽  
Louay N. Mohammad ◽  
Samuel B. Cooper
Keyword(s):  
Hot Mix Asphalt ◽  
Permanent Deformation ◽  
Fatigue Cracking ◽  
Strain Energy Release ◽  
Asphalt Mixtures ◽  
Bending Test ◽  
Test Results ◽  
Recycled Asphalt ◽  
Recycled Asphalt Shingles ◽  
Asphalt Shingles

The use of recycled asphalt shingles (RAS) in asphalt paving construction represents a sustainable approach to reduce virgin material consumption and negative environmental effects, as well as the cost of asphalt pavement. However, many challenges are yet to be addressed about the use of RAS in paving applications. This study evaluated the effect of the incorporation of postconsumer waste shingles and rejuvenators on the performance of hot-mix asphalt. Four asphalt rejuvenators—one bio-oil and three synthetic oils—were evaluated. A set of laboratory tests was conducted to characterize the performance of asphalt mixtures against permanent deformation and fatigue cracking. The addition of 5% RAS showed an improvement in permanent deformation when compared with a conventional mixture with no RAS. Yet the addition of asphalt rejuvenator products slightly decreased the performance against permanent deformation. On the basis of Hamburg wheel-tracking device test results, the addition of RAS did not adversely affect moisture resistance. Yet semicircular bending test results showed that the asphalt mixtures that contained asphalt rejuvenators had a lower critical strain energy release rate than the minimum threshold value (0.5 kJ/m2), which indicated a greater susceptibility to intermediate-temperature cracking.

scholarly journals Stiffness and Fatigue of Asphalt Mixtures for Pavement Construction

2018 ◽  
Vol 26 (2) ◽  
pp. 24-29 ◽  
Author(s):  
Juraj Šrámek
Keyword(s):  
Fatigue Life ◽  
Asphalt Mixture ◽  
Construction Materials ◽  
Test Methods ◽  
Asphalt Mixtures ◽  
Bending Test ◽  
Deformation Properties ◽  
Pavement Construction ◽  
And Control

AbstractThe quality of a road is affected by its correct design, the appropriate use of materials, the effects of the climate, and the technological discipline. The deformation properties and fatigue of asphalt layers are important for the design and assessment of semi-rigid and flexible pavements. The assessment of deformation properties is performed by means of a dynamic impact test and the fatigue life of a particular asphalt mixture. An evaluation of the fatigue life is based on decreases in resistance or increases in deformations in different binders and mixtures. The test methods for the design and control of pavement construction materials determine the basic conditions valid for flexible matter. The Two-Point Bending Test was used for determining the deformation characteristics and the fatigue of asphalt mixtures at the Department of Construction Management in Zilina.

Study on Dynamic Modulus of Waste Plastic Modified Asphalt Mixture Using Waste Plastic Bag Chips

2011 ◽  
Vol 261-263 ◽  
pp. 824-828 ◽  
Author(s):  
Qian Zhang ◽  
Shu Wei Goh ◽  
Zhan Ping You
Keyword(s):  
Phase Angle ◽  
Dynamic Modulus ◽  
Asphalt Mixture ◽  
Control Sample ◽  
Asphalt Mixtures ◽  
Test Results ◽  
Waste Plastic ◽  
Modified Asphalt ◽  
Plastic Bag ◽  
Dynamic Modulus Test

The objective of this study is to investigate the possibility of using waste plastic as an additive to modify asphalt mixtures thereby reducing the waste plastic stream in our environment. High density polyethylene plastic bags obtained from the retail store were shredded into chips and added into asphalt mixtures at the rate of 0% (control sample), 2, 5 and 8% based on binder weight. Three different temperatures of 4, 21.3 and 39.2°C and frequencies ranging from 0.1 to 25 Hz were used in the dynamic modulus test. It was found that most of the asphalt mixtures modified with waste plastic have higher dynamic modulus when compared with the control samples. However, no significant trend on phase angle was found among all the samples tested based on the test results. In this study, it was found that the modified asphalt mixture with 2% waste plastic had the highest dynamic modulus and phase angle. Based on the test results, it was found that plastic modified asphalt mixture will have a better performance under intermediate and high temperature conditions.

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