scholarly journals Effect of Crack Initiation and Life Prediction of Polyacrylonitrile-Reinforced Gussasphalt Surfacing over Steel Bridge Deck under Fiber Content Variation

Crystals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 155
Author(s):  
Xun Qian Xu ◽  
Wei Yang ◽  
Hong Liang Xiang ◽  
Jian Bo Wang ◽  
Xiao Yang

The crack initiation and life prediction of fiber-reinforced asphalt concrete (FRAC) surfacing for steel bridge decks under a cyclic vehicle load are analyzed from the perspective of damage mechanics. The damage field and the stress and strain field evolution rule of a composite beam in fatigue test are studied, and a fatigue failure criterion is proposed for steel deck FRAC surfacing. Bending fatigue tests are performed on composite beams composed of a steel deck and polyacrylonitrile (PAN)-fiber-reinforced Gussasphalt (GA), i.e., GA-PAN, concrete surfacing under different fiber content and temperature conditions. The damage evolution characteristics of GA-PAN concrete surfacing over the steel deck with different fiber lengths and volume ratios are predicted by analyzing the fatigue life equations. The results show that the steel bridge deck FRAC surfacing model can reflect the comprehensive influence of the fiber content and length on the fatigue performance of steel bridge AC. Specifically, a lower temperature results in the fiber more synergistically affecting the fatigue resistance of AC. Theoretically, the service performance of asphalt concrete increases with the increase of fiber length and content. The optimum fiber length and volume ratio of GA-PAN are found to be 9 mm and 0.46–0.48%, respectively, considering the construction workability.

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4018
Author(s):  
Shuming Zhang ◽  
Yuanming Xu ◽  
Hao Fu ◽  
Yaowei Wen ◽  
Yibing Wang ◽  
...  

From the perspective of damage mechanics, the damage parameters were introduced as the characterizing quantity of the decrease in the mechanical properties of powder superalloy material FGH96 under fatigue loading. By deriving a damage evolution equation, a fatigue life prediction model of powder superalloy containing inclusions was constructed based on damage mechanics. The specimens containing elliptical subsurface inclusions and semielliptical surface inclusions were considered. The CONTA172 and TARGE169 elements of finite element software (ANSYS) were used to simulate the interfacial debonding between the inclusions and matrix, and the interface crack initiation life was calculated. Through finite element modeling, the stress field evolution during the interface debonding was traced by simulation. Finally, the effect of the position and shape size of inclusions on interface debonding was explored.


2019 ◽  
Vol 15 (5) ◽  
pp. 947-957 ◽  
Author(s):  
Giridharan R. ◽  
Raatan V.S. ◽  
Jenarthanan M.P.

Purpose The purpose of this paper is to study the effects of fiber length and content on properties of E-glass and bamboo fiber reinforced epoxy resin matrices. Experiments are carried out as per ASTM standards to find the mechanical properties. Further, fractured surface of the specimen is subjected to morphological study. Design/methodology/approach Composite samples were prepared according to ASTM standards and were subjected to tensile and flexural loads. The fractured surfaces of the specimens were examined directly under scanning electron microscope. Findings From the experiment, it was found that the main factors that influence the properties of composite are fiber length and content. The optimum fiber length and weight ratio are 15 mm and 16 percent, respectively, for bamboo fiber/epoxy composite. Hence, the prediction of optimum fiber length and content becomes important, so that composite can be prepared with best mechanical properties. The investigation revealed the suitability of bamboo fiber as an effective reinforcement in epoxy matrix. Practical implications As bamboo fibers are biodegradable, recyclable, light weight and so on, their applications are numerous. They are widely used in automotive components, aerospace parts, sporting goods and building industry. With this scenario, the obtained result of bamboo fiber reinforced composites is not ignorable and could be of potential use, since it leads to harnessing of available natural fibers and their composites rather than synthetic fibers. Originality/value This work enlists the effect of fiber length and fiber content on tensile and flexural properties of bamboo fiber/epoxy composite, which has not been attempted so far.


Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1556 ◽  
Author(s):  
Fucheng Guo ◽  
Rui Li ◽  
Shuhua Lu ◽  
Yanqiu Bi ◽  
Haiqi He

Fiber-reinforced asphalt mixture has been widely used in pavement engineering to not only prevent asphalt binder leakage but also improve engineering properties of asphalt mixture. However, the research on three key parameters, namely fiber type, fiber length, and fiber content, which significantly affect the performance of fiber-reinforced asphalt mixture, have seldom been conducted systematically. To determine these three key parameters in the support of the application of fibers in mixture scientifically, three commonly used fibers were selected, basalt fiber, polyester fiber, and lignin fiber, and the testing on fibers, fiber-reinforced asphalt binders, and fiber-reinforced asphalt mixtures was conducted afterwards. The results showed: the favorable fiber type was basalt fiber; the favorable basalt fiber length was 6mm; the engineering properties including high temperature stability, low temperature crack resistance, and water susceptibility were clearly improved by the added basalt fiber, and the optimum basalt fiber content was 0.4 wt.%. The obtained results may be valuable from a practical point of view to engineers and practitioners.


2008 ◽  
Vol 41-42 ◽  
pp. 313-316 ◽  
Author(s):  
Li Ping He ◽  
Yong Tian ◽  
Lu Lin Wang

Natural fiber reinforced polypropylene composites (NF/PP) have attracted a lot of attention because of their light weight, good mechanical properties, recyclable and environmental friendly features. This work has successfully fabricated ramie fiber reinforced polypropylene composites (RF/PP) with a hybrid method of melt-blending and injection molding. Different RF/PP eco-materials have been fabricated by varying the fiber length, fiber content and way of fiber pre-treatment. This paper studied the mechanical properties of the fabricated RF/PP composites in depth by investigating the mechanical behaviors of RF/PP and microstructures of the ruptured surfaces. The results show that the increases of fiber length and fiber content can improve the tensile strength, flexural strength and compression strength apparently, but result in negative influences on the impact strength and elongation behaviors of RF/PP composites. The optimal addition amount of ramie fiber is around 20 wt%. The pre-treatment of ramie fiber in 10%~15% NaOH is good to the mechanical properties of RF/PP. The fiber length can be varied in the range of 3-8 mm. It is expected that the fabricated RF/PP composites can be applied to automobile industry as environmental friendly eco-materials.


2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Hui Zhang ◽  
Chengqi Zhou ◽  
Kuan Li ◽  
Peiwei Gao ◽  
Youqiang Pan ◽  
...  

Fatigue cracks are main damages to steel bridge deck pavement with thermosetting epoxy asphalt. By combining a high-toughness resin material with fiber woven fabrics, this study formed an ultrathin overlay of fiber-reinforced high-toughness resin to improve cracking resistance of pavement. Through theoretical measurement and bending test, this research studied change laws of bending and tensile properties of epoxy asphalt concrete after fiber reinforcement and analyzed bending strength and the maximum failure strain of beams at different temperatures. Moreover, the reinforcing effects of different fibers were discussed. It is found that bending strength, maximum failure strain, and stiffness modulus of the beams with epoxy asphalt are improved after fiber reinforcement. With the decrease of temperature, after fiber reinforcement, the mode of bending failure of the epoxy asphalt mixture (EAM) changes from brittle fracture into shear failure, accompanied with significant yield phenomenon. Furthermore, organic carbon fiber is sensitive to influences of temperature, while glass fiber is least sensitive to temperature.


2020 ◽  
Vol 10 (24) ◽  
pp. 9043
Author(s):  
Yingying Zhao ◽  
Xianzhang Ling ◽  
Weigong Gong ◽  
Peng Li ◽  
Guoyu Li ◽  
...  

To study the mechanical properties of Y-shaped polypropylene fiber-reinforced subgrade fill, the strength characteristics of fiber-reinforced soil with different fiber contents, fiber lengths, and confining pressures were investigated through triaxial compression tests. The test results showed that fiber reinforcement significantly improved the strength and cohesion of the subgrade fill but had a limited impact on the internal friction angle. The fiber-reinforced soil specimens exhibited a failure pattern of bulging deformation, showing plastic failure characteristics. As the fiber content and length increased, the strength of the fiber-reinforced soil increased and then decreased. The optimal fiber content was 0.2%, and the optimal fiber length was between 12 and 18 mm in all test conditions. The strength of the fiber-reinforced soil increased with increasing confining pressure. An empirical model for predicting the failure strength of fiber-reinforced soil was established by analyzing the relationships between the failure strength of the fiber-reinforced soil and the fiber content, fiber length, and confining pressure. The stress-strain relationship of the fiber-reinforced soil exhibited strain-hardening characteristics and could be approximated by a hyperbolic curve. The Duncan-Chang model could be used to describe the stress-strain relationship of this fiber-reinforced soil. A calculation method to determine the model parameters (initial tangent modulus and ultimate deviator stress) was proposed.


2013 ◽  
Vol 13 (21) ◽  
pp. 4666-4670 ◽  
Author(s):  
Xiu Liu ◽  
Zhaojie Sun ◽  
Decheng Feng ◽  
Yixiang Cao

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