Fatigue Life Analysis of Asphalt Mixture Coupling with Loading Intermittent Time

2012 ◽  
Vol 204-208 ◽  
pp. 3852-3858 ◽  
Author(s):  
Li Qiang Luan ◽  
Xiao Ge Tian
Keyword(s):  
Asphalt Concrete ◽  
Fatigue Testing ◽  
Testing Machine ◽  
Asphalt Mixture ◽  
Time Factor ◽  
Repeated Loading ◽  
Self Healing ◽  
Effect Factor ◽  
Higher Temperature ◽  
Fatigue Life Analysis

Repeated loading will produce cumulative damage to asphalt concrete, because of the visco-elastic property of asphalt concrete, a certain degree of self-healing may occurred in case the loads being taken away.( the healing effect is more obvious under higher temperature or pressure),this process can be indicated through adding the intermittent time factor to fatigue test of asphalt concrete .This study adds intermittent time factor to asphalt concrete fatigue testing through universal testing machine,, deeply analyzing the effect of intermittent time, confirming that 0.5 second intermittent time is a key time point to fatigue process ,fatigue rate under 15 °C is slower than that under 20 °C,and introducing the effect factor to the fatigue equation.

Evaluation of Pyrolized Carbon Black from Scrap Tires as Additive in Hot Mix Asphalt

1996 ◽  
Vol 1530 (1) ◽  
pp. 43-50 ◽  
Author(s):  
Taesoon Park ◽  
Brian J. Coree ◽  
C. W. Lovell
Keyword(s):  
Carbon Black ◽  
Asphalt Concrete ◽  
Resilient Modulus ◽  
Testing Machine ◽  
Asphalt Mixture ◽  
Asphalt Mixtures ◽  
Test Results ◽  
Reinforcing Agent ◽  
Dynamic Creep ◽  
Temperature Susceptibility

The viability of using pyrolized carbon black (CBp) derived from waste tires as a reinforcing agent in asphalt mixtures was evaluated. Commercial carbon black (CB) has been previously shown to reduce the rutting resistance, temperature susceptibility, and cracking propagation potential of asphalt concrete. It was believed that CBp could produce similar benefits; this belief has been confirmed by this study. Different ratios of CBp and CB (5, 10, 15, and 20 percent by weight of asphalt) were blended with two grades of asphalt (AC-10 and AC-20). The Marshall method, the gyratory testing machine, the dynamic creep testing (confined), the indirect tensile testing, and the resilient modulus test were performed. The test results of CBp mixtures were compared with results of CB and conventional mixtures. The analyses of test results show that the typical performance of CBp-modified asphalt mixtures is improved with respect to commercial CB and conventional mixtures. The rutting potential and the temperature susceptibility can be reduced by the inclusion of CBp in the asphalt mixture. A CBp content of 10 to 15 percent by weight of asphalt is recommended for improvement of asphalt concrete.

scholarly journals The Effect of UV Irradiation on the Chemical Structure, Mechanical and Self-Healing Properties of Asphalt Mixture

Materials ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2424 ◽  
Author(s):  
Shaopeng Wu ◽  
Yong Ye ◽  
Yuanyuan Li ◽  
Chuangmin Li ◽  
Wei Song ◽  
...  
Keyword(s):  
Uv Radiation ◽  
Fatigue Resistance ◽  
Uv Irradiation ◽  
Asphalt Concrete ◽  
Bending Strength ◽  
Irradiation Time ◽  
Asphalt Binder ◽  
Asphalt Mixture ◽  
Aging Effect ◽  
Self Healing

Although huge numbers of investigations have been conducted for the ultraviolet (UV) aging of asphalt binder, research rarely focuses on the asphalt mixture. In order to evaluate the aging effect of UV radiation on the asphalt mixture, a dense grade of asphalt mixture was designated and aged by UV radiation for 7, 14 and 28 days respectively. After that, the chemical functional groups of asphalt binder were tested by Fourier transform infrared spectrometer (FTIR). The semi-circular bending strength and fatigue resistance of asphalt concrete were tested to characterize the mechanical properties of the asphalt concrete. To evaluate the self-healing effect of the macro-structure continuity of asphalt concrete intuitively, the computed tomography (CT) scanning machine was used to characterize the crack size of asphalt concrete samples both before and after self-healing. The results show that, with the increase of UV irradiation time, the relative ratios of the C=O and S=O bands’ areas of recovered asphalt binder increase significantly. UV radiation can significantly weaken the mechanical and self-healing properties of asphalt mixture, making the asphalt mixture to have worse macro-structure continuity, lower failure strength and worse fatigue resistance. Moreover, the longer the UV irradiation time is, the degradation effect of UV radiation on asphalt mixture becomes more obvious.

Investigation of Creep Mechanics Properties of Layered Nano-Montmorillonite Modified Asphalt Mixtures

2011 ◽  
Vol 467-469 ◽  
pp. 1541-1545 ◽  
Author(s):  
Tian Gui Liu ◽  
Shao Peng Wu ◽  
Jun Han
Keyword(s):  
Elastic Property ◽  
Asphalt Concrete ◽  
Permanent Deformation ◽  
Asphalt Binder ◽  
Testing Machine ◽  
Asphalt Mixture ◽  
Layered Silicate ◽  
Asphalt Mixtures ◽  
Modified Bitumen ◽  
Modified Asphalt

Montmorillonite（MMT）is a typical layered silicate. It has been widely used to modify polymers. It improves the thermal, mechanical and aging properties of polymers. The prominent features of MMT modified asphalt concrete are significant for prolonging the service life of asphalt pavement. The profound researches on the service performance and mechanical characteristics of MMT modified asphalt binder and mixtures are important for the application of MMT modified asphalt concrete in practice projects. The effect of MMT on the creep properties of asphalt mixture has been investigated in the research. The result showed that the physical capabilities of MMT modified bitumen was improved evidently. UTM 25 electro-hydraulic servo-universal testing machine was used to do Creep Text, and proper rheological models are employed to describe such characteristics. Results indicated that the visco-elastic properties of the mixtures can be changed by the use of MMT. The revised Burgers model is suitable for the visco-elastic property research of MMT modified asphalt mixtures. The model demonstrated that the retardant visco-elastic property and viscous property of asphalt mixtures containing MMT can be improved, which result in the enhancement of resistance to permanent deformation for MMT modified asphalt mixtures.

Research on the Fatigue Character of ERW Pipe Welded Seam and Fatigue Life Assessment Method

2010 ◽  
Author(s):  
Guangli Zhang ◽  
Jinheng Luo ◽  
Xinwei Zhao ◽  
Hua Zhang ◽  
Liang Zhang ◽  
...  
Keyword(s):  
Fatigue Life ◽  
Stress Ratio ◽  
Fatigue Testing ◽  
Testing Machine ◽  
Assessment Method ◽  
Life Assessment ◽  
Repeated Loading ◽  
Fatigue Crack Propagation Rate ◽  
Line Pipe ◽  
Fatigue Life Assessment

The fatigue character of electric resistance weld (ERW) seams in API X65 grade line pipe steel at the stress ratio of 0.1 and 0.6 have been investigated. Repeated loading was applied to compact tension specimen, and the fatigue crack propagation rate and threshold of X65 ERW pipe seam are tested using high-frequency fatigue testing machine. Radiographic inspection has shown that the crack caused by the cold welding is the main weld defect in the ERW pipe. Based on the failure assessment diagram (FAD) recommended in the API 579-2007 and the Miner’s linear cumulative damage model, considering the influence of stress ratio to the fatigue life, the fatigue life assessment method for the ERW pipe containing seam defects is established.

scholarly journals Influence of Microcrack Healing Techniques on Tensile Strength of Asphalt

2020 ◽  
Vol 1 (3) ◽  
pp. 27-32
Author(s):  
Saad Issa Sarsam
Keyword(s):  
Tensile Strength ◽  
Asphalt Concrete ◽  
Early Stage ◽  
Healing Process ◽  
Asphalt Mixture ◽  
Indirect Tensile Strength ◽  
Repeated Loading ◽  
Before And After ◽  
Indirect Tensile ◽  
Asphalt Concrete Pavement

Asphalt concrete pavement practices repeated loading and environmental impacts and suffers distresses. Microcracks usually occurs at early stage of pavement life while the pavement can heal itself under controlled conditions. Microcrack healing process can be controlled and accelerated using various techniques. In this investigation, iron filling was implemented as partial substitute of sand to support the healing process while both induction and external heating techniques were adopted to control the healing using microwave and oven. Asphalt concrete specimens have been prepared with different percentages of iron filling and the corresponding required asphalt content. Specimens were subjected to repeated indirect tensile stresses for 600 and 1200 load repetitions. Specimens were allowed to heal using microwave and oven heating techniques. Specimens were subjected to another cycle of stress repetitions and the variation in the indirect tensile strength was detected before and after healing. The healing performance of the asphalt mixture specimens at different healing conditions was investigated by observing and testing the recovery of indirect tensile strength after healing. It was concluded that implementation of iron filling and induction heating by microwave can improve the healing and tensile properties of asphalt concrete as compared to the oven heating technique.

On a New Rotating Bending Fatigue Testing Machine

1966 ◽  
Vol 15 (148) ◽  
pp. 49-54
Author(s):  
Minoru KAWAMOTO ◽  
Katsumi SUMIHIRO ◽  
Koji KIDA
Keyword(s):  
Fatigue Testing ◽  
Testing Machine ◽  
Bending Fatigue ◽  
Rotating Bending Fatigue ◽  
Rotating Bending

Low Cycle Tension-Tension Fatigue Properties of 316L Stainless Steel Thin Sheets

2011 ◽  
Vol 138-139 ◽  
pp. 832-835
Author(s):  
Yong Jie Liu ◽  
Qing Yuan Wang ◽  
Ren Hui Tian ◽  
Xiao Zhao
Keyword(s):  
Stainless Steel ◽  
Room Temperature ◽  
316L Stainless Steel ◽  
Fatigue Testing ◽  
Fatigue Properties ◽  
Loading Frequency ◽  
Thin Sheets ◽  
Effect Factor ◽  
Mechanical Fatigue ◽  
Tensile Fatigue

In this paper, tensile fatigue properties of 316L stainless steel thin sheets with a thickness of 0.1 mm are studied. The tests are implemented by using micro mechanical fatigue testing sysytem (MMT-250N) at room temperature under tension-tension cyclic loading. The S-N curve of the thin sheets descends continuously at low cycle region. Cyclic σ-N curve and ε-N curve are obtained according to the classical macroscopical fatigue theory. The results agree well with the experimental fatigue data, showing that the traditional fatigue research methods are also suitable for description of MEMS fatigue in a certain extent. The effect factor of frequency was considered in this study and the results show that the fatiuge life and the fatigue strength are increased as loading frequency increasing.

Mitigation of permanent deformation in base layer containing recycled asphalt aggregates

2013 ◽  
Vol 40 (2) ◽  
pp. 181-187 ◽  
Author(s):  
Jean-Pascal Bilodeau ◽  
Guy Doré ◽  
Jonas Depatie
Keyword(s):  
Asphalt Concrete ◽  
Deformation Behaviour ◽  
Permanent Deformation ◽  
Design Procedure ◽  
Base Layer ◽  
Repeated Loading ◽  
Recycled Asphalt ◽  
Thickness Increase ◽  
Permanent Strain ◽  
Pavement Base

The use of recycled asphalt pavement (RAP) aggregates as replacement for new materials in the pavement base weakens the layer in regards to the resistance to permanent deformation under repeated loading. A mechanistic based design procedure is proposed to ensure that base layers containing RAP particles have a similar rutting behaviour to base layers made of virgin aggregates. The design procedure allows calculating an asphalt concrete thickness increase that is based on permanent deformation behaviour of base materials. The calculation approach is based on multistage triaxial permanent deformation tests performed on granular material samples with varied RAP content. The tests allowed proposing an equation that relates permanent strain rate, RAP content, and deviatoric stress, which is the basis of the design procedure. Design charts are proposed to select adequate thickness increase for the asphalt concrete layer according to the expected RAP content in the base layer and asphalt concrete modulus.

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