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.

scholarly journals Hybrid-Fiber-Reinforced Concrete Used in Frozen Shaft Lining Structure in Coal Mines

Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 3988 ◽  
Author(s):  
Zhishu Yao ◽  
Xiang Li ◽  
Taoli Wu ◽  
Long Yang ◽  
Xiaohu Liu
Keyword(s):  
Reinforced Concrete ◽  
Crack Resistance ◽  
High Strength Concrete ◽  
Coal Mines ◽  
High Strength ◽  
Fiber Reinforced Concrete ◽  
Hybrid Fiber ◽  
Strength Concrete ◽  
Lining Structure ◽  
Shaft Lining

To address the cracking and leaking of concrete in frozen shaft linings in deep and thick topsoil layers in coal mines, hybrid-fiber-reinforced concrete (HFRC) was developed. First, the composition of the reference concrete was obtained by investigating high-strength concrete commonly used in shaft linings, and two dosages of polyvinyl alcohol fiber (PVAF) and polypropylene plastic steel fiber (PPSF) were obtained by the mixing test. Then, tests of early cracks of concrete were conducted; results showed that HFRC could almost avoid early cracks, exhibiting an advantage in early crack resistance. Thus, HFRC can play a significant role in improving the durability of frozen shaft linings in complex underground environments. Furthermore, a series of mechanical property tests were carried out. The results showed that the compressive strength of HFRC was similar to that of the reference concrete, but the tensile and flexural strength of HFRC was 42.7% and 35.1% higher than that of the reference concrete, respectively. Finally, an analog simulation model test of shaft linings was conducted. The new type of shaft lining structure containing hybrid fibers (HFs) exhibited plastic deformation characteristics under load, and the maximum hoop strain was −3562 με. It addressed the problem of high brittleness of frozen shaft lining structures of ordinary high-strength concrete and improved the toughness and crack resistance. HFRC is an ideal material for frozen shaft lining structures in deep and thick topsoil.

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 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 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

Experimental Study of Bending Toughness on Hybrid Fiber Reinforced Concrete

2013 ◽  
Vol 327 ◽  
pp. 201-204
Author(s):  
Jin Song Shi ◽  
Bo Yuan ◽  
Da Zhang Wang ◽  
Zhe An Lu
Keyword(s):  
Experimental Study ◽  
Reinforced Concrete ◽  
Fiber Reinforced Concrete ◽  
Bending Test ◽  
Fiber Reinforced ◽  
Hybrid Fiber ◽  
Toughness Index ◽  
The Difference ◽  
Loading Methods ◽  
Index Value

In order to investigate the difference of current toughness index standards for fiber reinforced concrete, two main groups of specimens were made to take bending toughness test with the requirements of corresponded standards, loading methods and loading speeds, which are ASTM C1018 in America, ACI 544 and JSCE G552 in Japan. United with software Origin, the load-deflection curves gathered from bending test was calculated with relative standards. The results show that the calculated toughness index value with ASTM C1018-98 in America is more accurate with three grades but the requested deflection of testing is much longer than others while ACI 544 and JSCE G552 in Japan are quite the contrary.

Sign in / Sign up

Export Citation Format

Share Document