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 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 Mechanical properties of Hybrid steel/PVA fibers reinforced high strength concrete

2018 ◽  
Vol 199 ◽  
pp. 11005 ◽  
Author(s):  
Wasim Abbass ◽  
M. Iqbal Khan
Keyword(s):  
Mechanical Properties ◽  
High Strength Concrete ◽  
Steel Fiber ◽  
Research Work ◽  
High Strength ◽  
Fiber Reinforced Concrete ◽  
Hybrid Fiber ◽  
Strength Concrete ◽  
Flexural Performance ◽  
Micro Level

The high strength concrete exhibits improved compressive strength with drawback of brittle failure due to lack of tensile strength which can be catered by the addition of fibers. The efficient use of fibers with hybridization at macro and micro level can improve mechanical properties of high strength concrete. The effect of hybridization of hooked end steel macro fibers (60 mm) and PVA micro fibers (12 mm) with different dosages was investigated in this research work. The different percentage of steel and PVA were hybridized to find out the best combination of hybridized fibers in high strength concrete. The compressive and flexural properties of high strength concrete along with complete load vs deflection behaviour of hybrid fiber reinforced concrete were investigated. The results revealed that hybridization of macro and micro fibers provided better improvement in flexural performance. It was observed from the results that the hybrid combination of fibers of 1% macro steel fiber and 0.15% micro PVA fibers proved to be the best for enhancement in flexural performance of high strength concrete.

Test Research on Strength of Concrete Shaft Lining under Salt Disaster Corrosion

2014 ◽  
Vol 926-930 ◽  
pp. 645-648 ◽  
Author(s):  
Xu Rong Li ◽  
Hong Guang Ji ◽  
Jun Wang ◽  
Cheng Lin Song
Keyword(s):  
Compressive Strength ◽  
Flexural Strength ◽  
High Strength Concrete ◽  
High Strength ◽  
Solution Concentration ◽  
Test Results ◽  
Strength Concrete ◽  
Strength Change ◽  
Lining Structure ◽  
Shaft Lining

In order to study the strength change of high strength concrete shaft lining structure in underground complex environment resisting composite salt damage erosion, C70 high strength concrete test specimens were made and composite salt disaster solutions of different concentrations were compounded. The test results show that the coefficient of compressive strength and flexural strength of high strength concrete increase in early corrosion and then decline. The strength of specimen declines more quickly in higher corrosion solution concentration in latter time. The change law of the flexural strength is more complex than the compressive strength. Composite salt disaster solutions have little effect for no damage high strength concrete.

Development and some Prospects of the Shaft Lining Structure

2012 ◽  
Vol 166-169 ◽  
pp. 636-639
Author(s):  
Lin Lin Wu ◽  
Yong Guang Lian ◽  
Yong Xiang Kong ◽  
Yong Jun Ma ◽  
Bin Jiang ◽  
...  
Keyword(s):  
High Strength Concrete ◽  
Steel Plate ◽  
High Strength ◽  
Damage Mechanism ◽  
Strength Concrete ◽  
Advantages And Disadvantages ◽  
Composite Shaft ◽  
Lining Structure ◽  
Shaft Lining

The damage mechanism and causes of the shaft lining structures are introduced, and the advantages and disadvantages of some current shaft lining structures are analyzed. The prospects of steel plate-high strength concrete composite shaft lining structure are proposed in this paper.

scholarly journals Effect of size and shape of specimen on compressive strength of glass fiber reinforced concrete (GFRC)

2011 ◽  
Vol 9 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Rao Krishna ◽  
Rathish Kumar ◽  
B. Srinivas
Keyword(s):  
Compressive Strength ◽  
Reinforced Concrete ◽  
Glass Fiber ◽  
High Strength Concrete ◽  
High Strength ◽  
Fiber Reinforced Concrete ◽  
Strength Concrete ◽  
Size And Shape ◽  
Glass Fiber Reinforced ◽  
Compressive Strength Of Concrete

Concrete is a versatile material with tremendous applications in civil engineering construction. Structural concrete elements are generally made with concrete having a compressive strength of 20 to 35 MPa. Lately, there is an increase in use of high strength concrete (HSC) in major construction projects such as high-rise buildings, and bridges involving members of different sizes and shapes. The compressive strength of concrete is used as the most basic and important material property in the design of reinforced concrete structures. It has become a problem to use this value as the control specimen sizes and shapes are different from country to country. In India, the characteristic compressive strength is usually measured based on 150 mm cubes [1]. But, the ACI code of practice specifies the design compressive strength based on the standard 150x300 mm cylinders [2]. The use of 100x200 mm cylinders gained more acceptance as the need to test high strength concrete increases [3]. In this context the size and shape of concrete becomes an important parameter for the compressive strength. In view of the significance of compressive strength of concrete and due to the fact that the structural elements of different sizes and shapes are used, it is proposed to investigate the effect of size and shape of the specimen on the compressive strength of concrete. In this work, specimens of plain as well as Glass Fiber Reinforced Concrete (GFRC) specimens are cast in order to carry out a comparative study.

Repaired Reinforced Concrete Beams with Normal and High Strength Concrete

2013 ◽  
Vol 6 (2) ◽  
pp. 21-37
Author(s):  
Emad Yassin Khudhair
Keyword(s):  
Reinforced Concrete ◽  
High Strength Concrete ◽  
High Strength ◽  
Fiber Reinforced Concrete ◽  
Reinforced Concrete Beams ◽  
Wire Mesh ◽  
Strength Concrete ◽  
Strength And Deformation ◽  
Normal Strength ◽  
Concrete Elements

In resent years several attempts were undertaken to repair damaged reinforced concrete structures. Studies on the effectiveness of repaired and strengthened reinforced concrete elements which fail primarily due to formation of major flexural cracks are same what limited for normal strength concrete (NSC) and very limited for high strength concrete (HSC). The overall objective of the present work is to investigate the strength and deformation characteristics in flexure of reinforced HSC and NSC beams repaired with either with concrete alone or with fiber reinforced concrete or with Welded Wire Mesh (W.W.M). From the results obtained, it was found that the beams were adequately repaired and the general mode of failure was flexural. The repaired beams had higher strength than the original beams. All repaired beams exhibited significant decrease in deflection than the original beams.

Study on the Dynamic Performance of Steel Fiber Reinforced Concrete in SHPB Experiment

2013 ◽  
Vol 700 ◽  
pp. 140-143 ◽  
Author(s):  
Li Li Huang ◽  
Wei Shi
Keyword(s):  
Reinforced Concrete ◽  
High Strength Concrete ◽  
Steel Fiber ◽  
Dynamic Performance ◽  
High Strength ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Steel Fiber Reinforced Concrete ◽  
Strength Concrete ◽  
Shpb Test

It is important to enhance the ductility of high strength concrete (HSC), and one possible direction is to use steel fibers reinforced, named steel fiber reinforced high strength concrete (SFRHSC).In this paper, The crack characteristics of steel fiber reinforced concrete is investigated in the SHPB test. The incident wave and transmission wave varying with the time have been obtained by SHPB experiment. The relationship curve for stress and strain of material concrete has also been obtained.

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