scholarly journals Experimental Evaluation of the Influence of Aggregate Strength on the Flexural Cracking Behavior of Epoxy Asphalt Mixtures

Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1876
Author(s):  
Wei Xu ◽  
Xiaoshu Wei ◽  
Jintao Wei ◽  
Zhengxiong Chen

The flexural cracking resistance of an asphalt concrete mixture used in a steel bridge deck pavement needs to be higher than that of one used in ordinary pavement. In this study, mechanical experimental tests were used to evaluate the influence of the aggregate strength on the flexural cracking behavior of epoxy asphalt concrete (EAC). The aggregate fracture area of beam cross sections was quantitatively analyzed by digital image processing, and crack propagation in the mixture was analyzed using fracture mechanics theory. The bending test results showed that the EAC containing high-strength aggregates exhibited the highest flexural cracking resistance among all of the aggregate mixtures under the same conditions. The use of high-strength aggregates led to a reduction in the aggregate fracture area, thereby improving the flexural cracking resistance of the mixture. The aggregate strength had a significant influence on the flexural cracking propagation behavior of the mixture. Fatigue test results at strain-controlled levels of 600–1200 με and 15 °C showed that the aggregate strength had no evident influence on the fatigue properties of the EAC. It is recommended that high-strength aggregates are used to increase the fracture resistance of aggregates and the flexural crack resistance of EACs.

2011 ◽  
Vol 268-270 ◽  
pp. 659-663
Author(s):  
Hua Chen ◽  
Kan Kang ◽  
Lang Ni Deng

The method of applying prestress to CFRP plates can make full use of the characteristics of high-strength, enhance the force properties, prevent peeling damage and reduce the strain lag. Construction technology of prestressed CFRP plates strengthening reinforcement concrete beams was introduce in this paper, and bending test of 6 reinforcement concrete beams strengthened with prestressed CFRP plates were carried out based on the self-developed prestressed CFRP plates supporting anchorages. The test results indicate that the flexural capacity and crack resistance capacity can be increased compared with non-prestressed CFRP plates, and the construction technology can be adopted in practical projects.


2016 ◽  
Vol 10 (3) ◽  
pp. 189-194 ◽  
Author(s):  
Emil Evin ◽  
Miroslav Tomáš ◽  
Marek Výrostek

Abstract Materials other than standard and advanced high strength steels are remarkable for the thin-walled structures of the car-body in recent years in order to safety enhancement, weight and emission reduction, corrosion resistance improvement. Thus, there are presented in the paper the deformation properties of laser welded austenitic AISI 304 and ferritic AISI 430 stainless steels compared to these one measured for the high strength low alloyed steel H220PD. The properties were researched by tensile test and 3-point bending test with fixed ends on specimens made of basic material and laser welded one. The specimens were welded by solid state fiber laser YLS-5000 in longitudinal direction (the load direction). The deformation properties such as strength, stiffness and deformation work were evaluated and compared. The strength and stiffness were calculated from tensile test results and the deformation work was calculated from both, tensile test and 3-point bending test results. There has been found only minor effect of laser welding to the deformation properties for high strength low alloyed steel H220PD and austenitic stainless steel AISI 304. Otherwise, the laser welding strongly influenced the deformation work of the ferritic stainless steel AISI 430 as well as the elongation at tensile test.


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.


2010 ◽  
Vol 150-151 ◽  
pp. 470-474 ◽  
Author(s):  
Wen Qiang Wang ◽  
Hua Yan He

As a fair deck pavement material of its kind used in steel bridge, the epoxy asphalt concrete is considered much more superior to ordinary asphalt concrete in terms of road performance, while still greatly subject to the level of design and construction. Starting from a practical case of the epoxy asphalt concrete that has been applied in the deck pavement of Pingsheng Steel Bridge, this paper centers on a comprehensive study and discussion of the epoxy asphalt mixture, specifically in aspects of physical and mechanical performance test of stability under high temperature, performance under low temperature, tortuosity, immersion stability, linear contraction performance, fatigue performance and oil-erosion resistance performance. This will provide positive instruction for future deck pavements on steel bridges.


2012 ◽  
Vol 598 ◽  
pp. 504-510 ◽  
Author(s):  
Huan Yun Zhou ◽  
Yang Liu

Epoxy asphalt concrete has been widely used in China as an excellent paving material on long-span steel bridges. Analysis of its low-temperature thermal stress can be a more accurate grasp of pavement low temperature stress condition. The bending creep test of epoxy asphalt mixture was carried out at low temperatures to obtain the creep compliances and determine the relaxation module. Then the principal curves of the relaxation module were regressed in a form of Prony progression expression by Matlab. The relaxation module was further converted to the parameters needed in the viscous-elastic module in ANSYS software. Finally, a three-dimensional full-scale Finite Element model for steel box girder and asphalt overlay was constructed to analyze the stress scenario under low temperatures for the duration of 48 hours. The maximum temperature stress was only 2.45 MPa at a temperature of -20.4°C and thus no shrinkage cracks will occur.


2013 ◽  
Vol 330 ◽  
pp. 905-910 ◽  
Author(s):  
Cheng Zhu

The TAF epoxy asphalt concrete (EAC) is a new steel bridge deck pavement materials , the application of the TAF EAC is increasing in China. But the research for some of it's performance and construction technology is not throughly, which results in the useful life of the bridge deck paving materials greatly reducing. This paper focuses on the design and construction methods of the Japanese TAF epoxy asphalt concrete, and take the Humen bridge steel bridge deck pavement repair project in December 2011 for example.


Author(s):  
Xinling Wang ◽  
Guanghua Yang ◽  
Wenwen Qian ◽  
Ke Li ◽  
Juntao Zhu

AbstractEngineered cementitious composites (ECC) show the distinguished characteristics of high post-cracking resistance and ductility. High-strength stainless steel wire rope (HSSSWR) has been successfully used for restoring or strengthening of existing structures. By combining the advantages of these two materials, a new composite system formed by embedding HSSSWR into ECC was proposed and expected to be a promising engineering material for repair or strengthening of structures. To investigate the tensile failure mechanism and mechanical properties of HSSSWR-reinforced ECC, an experimental study on 27 HSSSWR-reinforced ECC plates was conducted considering the effects of the reinforcement ratio of longitudinal HSSSWRs, formula of ECC and width of the plate. Test results revealed that HSSSWR-reinforced ECC exhibit superior post-cracking resistance, deformation capacity and crack-width control capacity. Increasing the reinforcement ratio of longitudinal HSSSWRs can effectively enhance the tensile strength, crack-width control capacity, deformation capacity and tensile toughness of HSSSWR-reinforced ECC. Adding thickener in ECC can significantly improve the crack-width control capacity and deformation capacity of HSSSWR-reinforced ECC due to enhancing uniform distribution of polyvinyl alcohol fibers, but would slightly reduce the cracking stress and maximum tensile stress by bringing small bubbles in the matrix. The tensile properties of HSSSWR-reinforced ECC plates are almost not affected by varying the plate width. Besides, a tensile constitutive model was developed for charactering the stress–strain relationship of HSSSWR-reinforced ECC in tension. Based on mechanical theories and failure characteristics of HSSSWR-reinforced ECC, the model parameters were determined, and calculation equations of cracking stress and tensile strength were proposed. The accuracy of the developed model and calculation equations was verified by test results.


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