Exploring the recovery of fatigue damage in bituminous mixtures at macro-crack level: the influence of temperature, time, and external loads

2017 ◽  
Vol 18 (sup2) ◽  
pp. 293-303 ◽  
Author(s):  
Fernando Moreno-Navarro ◽  
Pooyan Ayar ◽  
Miguel Sol-Sánchez ◽  
M. Carmen Rubio-Gámez
Keyword(s):  
Fatigue Damage ◽  
Influence Of Temperature ◽  
Bituminous Mixtures ◽  
External Loads ◽  
Temperature Time

scholarly journals Strain energy-based rubber fatigue life prediction under the influence of temperature

2018 ◽  
Vol 5 (10) ◽  
pp. 180951 ◽  
Author(s):  
Jingnan Zhang ◽  
Fengxian Xue ◽  
Yue Wang ◽  
Xin Zhang ◽  
Shanling Han
Keyword(s):  
Fatigue Life ◽  
Prediction Model ◽  
Fatigue Damage ◽  
Strain Energy ◽  
Life Prediction ◽  
Least Square ◽  
Fatigue Life Prediction ◽  
Uniaxial Tensile ◽  
Influence Of Temperature ◽  
Different Temperatures

Aiming at the problem of the fatigue life prediction of rubber under the influence of temperature, the effects of thermal ageing and fatigue damage on the fatigue life of rubber under the influence of temperature are analysed and a fatigue life prediction model is established by selecting strain energy as a fatigue damage parameter based on the uniaxial tensile data of dumbbell rubber specimens at different temperatures. Firstly, the strain energy of rubber specimens at different temperatures is obtained by the Yeoh model, and the relationship between it and rubber fatigue life at different temperatures is fitted by the least-square method. Secondly, the function formula of temperature and model parameters is obtained by the least-square polynomial fitting. Finally, another group of rubber specimens is tested at different temperatures and the fatigue characteristics are predicted by using the proposed prediction model under the influence of temperature, and the results are compared with the measured results. The results show that the predicted value of the model is consistent with the measured value and the average relative error is less than 22.26%, which indicates that the model can predict the fatigue life of this kind of rubber specimen at different temperatures. What's more, the model proposed in this study has a high practical value in engineering practice of rubber fatigue life prediction at different temperatures.

Influence of Temperature-Time Mode of Crystallization on Electrophysical Characteristics of the Polypropylene/Magnetite Nanocomposite

2019 ◽  
Vol 201 (1) ◽  
pp. 218-223
Author(s):  
M. A. Ramazanov ◽  
H. A. Shirinova ◽  
F. V. Hajiyeva ◽  
A. Kh. Karimova
Keyword(s):  
Magnetic Field ◽  
Dielectric Permittivity ◽  
Cooling Rate ◽  
Polymer Nanocomposites ◽  
Hot Pressing ◽  
Nanocomposite Materials ◽  
Negative Magnetoresistance ◽  
Electrophysical Properties ◽  
Influence Of Temperature ◽  
Temperature Time

In the present study, the influence of the temperature–time mode of crystallization (TTC) on the electrophysical properties of polymer-based PP + Fe3O4 nanocomposite materials was investigated. Also, the effect of the temperature-time mode of crystallization of nanocomposites on the negative magnetoresistance (NMR) effect that observed in this material was investigated. It was found that dielectric permittivity of polymer nanocomposites rises with increasing of cooling rate. The cooling rate of nanocomposites after hot-pressing also affects the NMR effect of these materials. The conductivity of the material under the influence of magnetic field improves with increasing of its cooling rate, which leads to increasing of NMR effect.

scholarly journals Preparation of SBS Modified Emulsified Asphalt in High Cold Region

2019 ◽  
Vol 275 ◽  
pp. 04004
Author(s):  
HOU Yanming
Keyword(s):  
Development Time ◽  
Cold Region ◽  
Influence Of Temperature ◽  
Modified Asphalt ◽  
Cold Area ◽  
Asphalt Modification ◽  
Road Performance ◽  
Emulsified Asphalt ◽  
Sbs Modified Asphalt ◽  
Temperature Time

A kind of SBS modified emulsified asphalt for highly cold area was studied by experiments. The research includes two aspects: the first is preparation of SBS modified asphalt. The influence of temperature, time, shear rate and development time on asphalt modification are determined, so as to determine the process of SBS modified asphalt. On this basis, the blending ratio of SBS modified emulsified asphalt was determined by experiments. The results show that the emulsified asphalt produced by the equipment is of good quality and good ductility.4%SBS latex content can make emulsified asphalt meet the standard requirements, but only 6%SBS latex content can obtain better road performance. Although the softening point of SBS modified emulsified asphalt prepared by this method is still low, it can meet the requirements of high cold area.

scholarly journals Precipitation of Germanium from Sulphate Solutions Containing Tin and Indium Using Tannic Acid

2019 ◽  
Vol 9 (5) ◽  
pp. 966 ◽  
Author(s):  
Michał Drzazga ◽  
Andrzej Chmielarz ◽  
Grzegorz Benke ◽  
Katarzyna Leszczyńska-Sejda ◽  
Magdalena Knapik ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Tannic Acid ◽  
Process Conditions ◽  
Influence Of Temperature ◽  
Temperature Time

The precipitation of tannin complex of germanium from sulfuric solutions obtained after dross leaching was investigated. The tested solutions contained mainly zinc, germanium, indium, and tin. The influence of temperature, time, amount of added tannic acid and its purity was determined. The application of pure tannic acid allowed the precipitation of >99% of germanium and decreased its concentration in a solution <0.015 g/dm3. It required ca. 11–13 g of pure tannic acid per each 1 g of dissolved germanium. The preferred process conditions for Ge precipitation using powder tannic acid were 90 °C, 90 min, whereas for 20% aq. solution—5 min. It was found that 40% to 50% of tin coprecipitated at these conditions. Therefore, a detinning operation using hydrogen peroxide was proposed. It allowed the removal of >99% Sn and reduced its concentration in the solution below 0.025 g/dm3.

Influence of Temperature and Increasing Traffic Flow on the Fatigue Damage of Welded Bridge Decks

2007 ◽  
Vol 348-349 ◽  
pp. 341-344 ◽  
Author(s):  
Tong Guo ◽  
Ai Qun Li ◽  
Zhao Xia Li
Keyword(s):  
Traffic Flow ◽  
Fatigue Damage ◽  
Suspension Bridge ◽  
Life Assessment ◽  
Element Analysis ◽  
Influence Of Temperature ◽  
Linear Effect ◽  
Long Span ◽  
Traffic Growth ◽  
Using Data

Fatigue life assessment of critical bridge members using online monitoring data has been investigated in recent years. To make a quick and efficient evaluation, a representative block of strain cycles is usually defined. However, such block sometimes fails to cover the change in fatigue damage by temperature fluctuation and traffic growth, which is important to the life prediction of the welds in a long-span suspension bridge. To find the influence of temperature and traffic volume on the fatigue damage, an equivalent vehicle load method is dedicated through finite element analysis, and the statistical disposition of traffic flow has been conducted, using data from the Runyang Bridge. The influence of traffic growth can be estimated and eliminated from the total damage so that the temperature effect on the fatigue damage is finally obtained. It is found that temperature has a linear effect on the fatigue damage. According to the fitted relationship between fatigue damage, temperature and the traffic flow, a more objective fatigue assessment is undertaken, based on the rain-flow counting method and the Palgren-Miner rule.

Preparation of WPU Wet-Rubbing Fastness Improver

2015 ◽  
Vol 1094 ◽  
pp. 109-112 ◽  
Author(s):  
Shu Ling Cui
Keyword(s):  
Polyethylene Glycol ◽  
Propionic Acid ◽  
Waterborne Polyurethane ◽  
Diphenylmethane Diisocyanate ◽  
Optimal Process ◽  
Influence Of Temperature ◽  
Temperature Time ◽  
Dimethylol Propionic Acid

A wet-rubbing fastness improver was prepared by two steps: (1) synthesis of waterborne polyurethane (WPU) through the reaction of diphenylmethane diisocyanate (MDI), polyethylene glycol (PEG), dimethylol propionic acid (DMPA), and diethylenetriamine; (2) modification of WPU by reaction with epichlorohydrin. Influence of temperature, time, concentration and ratio of monomers on the preparation was studied. The optimal process for WPU synthesis is as follows: temperature 100°C, time 3h, diethylenetriamine 1.5 % and DMPA7% (on weight of monomers). The modification reaction can be proceeded at temperature 100°C for 2h with epichlorohydrin 2.7 %.

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