scholarly journals Experimental Study on Durability of Hybrid Fiber-Reinforced Concrete in Deep Alluvium Frozen Shaft Lining

Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 725
Author(s):  
Zhishu Yao ◽  
Yu Fang ◽  
Ping Zhang ◽  
Xianwen Huang
Keyword(s):  
Corrosion Resistance ◽  
Reinforced Concrete ◽  
Reference Group ◽  
Fiber Reinforced Concrete ◽  
Test Results ◽  
Fiber Reinforced ◽  
Hybrid Fiber ◽  
Freeze Thaw ◽  
Thaw Cycle ◽  
Shaft Lining

This article proposes hybrid fiber-reinforced concrete (HFRC) mixed with polyvinyl alcohol fiber (PVA) and polypropylene steel fiber (FST) as a wall construction material to improve the bearing capacity and durability of frozen shaft lining structures in deep alluvium. According to the stress characteristics and engineering environment of the frozen shaft lining, the strength, impermeability, freeze–thaw damage, and corrosion resistance are taken as the evaluation and control indexes. The C60 concrete commonly used in freezing shaft lining is selected as the reference group. Compared to the reference group, the test results show that the compressive strength of HFRC is similar to that of the reference concrete, but its splitting tensile strength and flexural strength are higher; according to the strength test, the optimum mixed content of 1.092 kg/m3 PVA and 5 kg/m3 FST are obtained. According to the impermeability test results, the mixing of PVA and FST can improve the impermeability resistance of concrete. For the freeze–thaw cycle test results, the mixing of PVA and FST can improve the frost resistance of concrete; based on the 120 days sulfate corrosion test, the mixing of PVA and FST will improve the corrosion resistance of concrete.

scholarly journals Experimental Study on Mechanical Properties of High Performance Hybrid Fiber Concrete for Shaft Lining

2021 ◽  
Vol 11 (17) ◽  
pp. 7926
Author(s):  
Qian Zhang ◽  
Wenqing Zhang ◽  
Yu Fang ◽  
Yongjie Xu ◽  
Xianwen Huang
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Reinforced Concrete ◽  
Reference Group ◽  
Splitting Tensile Strength ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Hybrid Fiber ◽  
Fiber Concrete ◽  
Shaft Lining

In order to solve the problem of highly brittle shaft lining under dynamic loading, a combination of hybrid fiber concrete mixed with steel and polypropylene fiber is proposed to make shaft lining. C60, the concrete commonly used in shaft lining, was selected as the reference group. The static mechanical properties, dynamic mechanical properties, and crack failure characteristics of the hybrid fiber concrete were experimentally studied. The test results showed that compared to the reference group concrete, the compressive strength of the hybrid fiber-reinforced concrete did not significantly increase, but the splitting tensile strength increased by 60.4%. The split Hopkinson compression bar results showed that the optimal group peak stress and peak strain of the hybrid fiber concrete increased by 58.2% and 79.2%, respectively, and the dynamic toughness increased by 68.1%. The strain distribution before visible cracks was analyzed by the DIC technology. The results showed that the strain dispersion phenomenon of the fiber-reinforced concrete specimen was stronger than that of the reference group concrete. By comparing the crack failure forms of the specimens, it was found that compared to the reference group concrete, the fiber-reinforced concrete specimens showed the characteristics of continuous and slow ductile failure. The above results suggest that HFRC has significantly high dynamic splitting tensile strength and compressive deformation capacity, as well as a certain anti-disturbance effect. It is an excellent construction material for deep mines under complex working conditions.

scholarly journals Numerical Analysis of a Novel Shaft Lining Structure in Coal Mines Consisting of Hybrid-Fiber-Reinforced Concrete

Crystals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 928
Author(s):  
Xuesong Wang ◽  
Hua Cheng ◽  
Taoli Wu ◽  
Zhishu Yao ◽  
Xianwen Huang
Keyword(s):  
Reinforced Concrete ◽  
Coal Mines ◽  
Fiber Reinforced Concrete ◽  
Inside Surface ◽  
Surface Load ◽  
Maximum Relative Error ◽  
Fiber Reinforced ◽  
Hybrid Fiber ◽  
Lining Structure ◽  
Shaft Lining

To address the temperature cracking of concrete in frozen shaft linings in extra-thick alluvial layers in coal mines, a novel shaft lining structure of coal mines consisting of hybrid-fiber-reinforced concrete (HFRC) was developed. Using the Finite Element Method (FEM), a numerical simulation test of the HFRC shaft lining structure with four factors and three levels was carried out, and the mechanical characteristics of the shaft lining structure were obtained. The results show that under a uniform surface load, the maximum hoop stress position of the HFRC shaft lining presents a transition trend from the inside surface to the outside surface; the hoop strain of shaft lining concrete is always a compressive strain, and the inside surface is greater than the outside surface. The empirical formula for the ultimate capacity of this new type of shaft lining structure was obtained by fitting. Compared with the model test results, the maximum relative error of the calculated value is only 6.69%, which provides a certain reference value for designing this kind of shaft lining structure.

Anlysis on Freeze-Thaw Cycling Damage of Layered Hybrid Fiber Reinforced Concrete

2012 ◽  
Vol 226-228 ◽  
pp. 1743-1746
Author(s):  
Dong Qing He ◽  
Bo Liu
Keyword(s):  
Reinforced Concrete ◽  
Damage Model ◽  
Plain Concrete ◽  
Fiber Reinforced Concrete ◽  
Steel Fibers ◽  
Fiber Reinforced ◽  
Hybrid Fiber ◽  
Damage Propagation ◽  
Freeze Thaw ◽  
Damage Process

Based on the least squares theory and a damage variable , a damage model is formed for the freeze-thaw degradation of the layered hybrid fiber reinforced concrete (LHFRC). By the model the degradation equations for the LHFRC and the plain concrete(PC) are regressed with the experimental data, which are identical in the initial phase and different in the damage propagation phase and the is used to describe the damage process of concrete subjected to freeze-thaw cycles. The of LHFRC is smaller than that of PC in the damage propagation phase. Furthermore, the frost resistance of LHFRC is stronger than that of PC due to steel fibers and polypropylene fibers having retarded the degradation of concrete.

Orthogonal Test of Flexural Toughness for Hybrid Fiber Reinforced Concretes

2011 ◽  
Vol 239-242 ◽  
pp. 2006-2010
Author(s):  
Xiao Fan Liu ◽  
Guo Dong Mei ◽  
Ji Xiang Li ◽  
Yun Xia Lun
Keyword(s):  
Reinforced Concrete ◽  
Steel Fiber ◽  
Polypropylene Fiber ◽  
Fiber Reinforced Concrete ◽  
Test Results ◽  
Fiber Reinforced ◽  
Hybrid Fiber ◽  
Hybrid Fibers ◽  
Concrete Matrix ◽  
Orthogonal Tests

Orthogonal tests are designed for hybrid fiber reinforced concrete. Bending toughness of hybrid fiber reinforced concrete, with the substrate intensity C30, the quantity of the volume for the steel fiber dosage 0~1.5% and polypropylene fiber dosage 0~0.3%, are studied. The results show that the hybrid fibers significantly improve the toughness of the concrete matrix. When the dosage reaches to a certain number, the affection of fiber toughness is decreased. Based on the test results the best dosage of hybrid fibers which is the steel fiber 1% mixed with 0.1% polypropylene fiber is recommended.

Crack Resistance and Permeability of Hybrid Fiber Reinforced Concrete Application in Understructure Work

2013 ◽  
Vol 438-439 ◽  
pp. 257-261
Author(s):  
Shu Jin Li ◽  
Hong Ping Qian
Keyword(s):  
Reinforced Concrete ◽  
Cellulose Fiber ◽  
Fiber Reinforced Concrete ◽  
Matrix Cracking ◽  
Test Results ◽  
Fiber Reinforced ◽  
Hybrid Fiber ◽  
Hybrid Fibers ◽  
Cracking Performance ◽  
Pva Fiber

An investigation of early anti-cracking performance and permeability of hybrid cellulose fiber and PVA fiber reinforced concrete is presented in this article. The test results show that, both cellulose fiber and PVA fiber effectively improve the splitting tensile strength. The early anti-cracking performance of concrete is obviously improved by PVA and cellulose hybrid fibers, and there exists the synergistic effect for restrain matrix cracking with hybrid fibers. Based on the practical application of a subway station project during two years, result shows the underground concrete wallboard containing hybrid fibers does not produce obvious cracks and leakage problem.

On axial compressive behavior of steel fiber reinforced concrete confined by FRP

2021 ◽  
pp. 136943322098165
Author(s):  
Hossein Saberi ◽  
Farzad Hatami ◽  
Alireza Rahai
Keyword(s):  
Reinforced Concrete ◽  
Experimental Test ◽  
Steel Fiber ◽  
Experimental Tests ◽  
Fiber Reinforced Concrete ◽  
Steel Fibers ◽  
Test Results ◽  
Fiber Reinforced ◽  
Steel Fiber Reinforced Concrete ◽  
Frp Confinement

In this study, the co-effects of steel fibers and FRP confinement on the concrete behavior under the axial compression load are investigated. Thus, the experimental tests were conducted on 18 steel fiber-reinforced concrete (SFRC) specimens confined by FRP. Moreover, 24 existing experimental test results of FRP-confined specimens tested under axial compression are gathered to compile a reliable database for developing a mathematical model. In the conducted experimental tests, the concrete strength was varied as 26 MPa and 32.5 MPa and the steel fiber content was varied as 0.0%, 1.5%, and 3%. The specimens were confined with one and two layers of glass fiber reinforced polymer (GFRP) sheet. The experimental test results show that simultaneously using the steel fibers and FRP confinement in concrete not only significantly increases the peak strength and ultimate strain of concrete but also solves the issue of sudden failure in the FRP-confined concrete. The simulations confirm that the results of the proposed model are in good agreement with those of experimental tests.

scholarly journals A review on hybrid fiber reinforced concrete pavements technology

2021 ◽  
Vol 1895 (1) ◽  
pp. 012053
Author(s):  
Hadeel M. Shakir ◽  
Ahmed Farhan Al-Tameemi ◽  
Adel A. Al-Azzawi
Keyword(s):  
Reinforced Concrete ◽  
Fiber Reinforced Concrete ◽  
Concrete Pavements ◽  
Fiber Reinforced ◽  
Hybrid Fiber
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