scholarly journals Study on Mechanical Properties of Basalt Fiber-Reinforced Concrete with High Content of Stone Powder at High Temperatures

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Lina Xu ◽  
Daohan Song ◽  
Ning Liu ◽  
Wei Tian

Concrete materials are an important part of global structure, and their fire resistance directly affects the safety of buildings and tunnels. In this study, basalt fiber was used to reinforce concrete with high content of stone powder in order to enhance its high-temperature performance. The mechanical properties and ultrasonic characteristics at different temperatures were studied using the cube compressive strength test and nonlinear ultrasonic test. The results indicated that the addition of basalt fiber in specimens improved their compressive strength; however, this strength did not continuously increase with increases in the fiber length and fiber content, and the optimal values for fiber length and fiber content were determined to be 12 mm and 1 kg/m3 at 600°C, respectively. With increases in temperature, the unconfined compressive strength increased first and then decreased. When the temperature was 400°C, the unconfined compressive strength of the specimens reached their highest values and then decreased. When the temperature was 400°C and 600°C, the strength of the stone powder concrete with fiber was higher than that without fiber, which shows that fiber can improve the mechanical properties of concrete at high temperatures. Based on the Box-Behnken design (BBD) method, the unconfined compressive strength response regression model of basalt fiber-reinforced concrete with high content of stone powder, which follows parameters including fiber content, fiber length, and temperature at high-temperature environments, was established, and it was found that the interaction of fiber content, fiber length, and the temperature was significant based on multifactor interaction analysis. The analysis of ultrasonic signals based on the S transform showed that, with increases in temperature, the amplitudes of the acoustic response signals, the corresponding frequency spectrum, and the time-frequency spectrum were clearly reduced. At the same temperature, the amplitudes of the acoustic response signals of different concrete testing blocks did not change much and remained at the same level.

2019 ◽  
Vol 2019 ◽  
pp. 1-17 ◽  
Author(s):  
Xinzhong Wang ◽  
Jun He ◽  
Ayman S. Mosallam ◽  
Chuanxi Li ◽  
Haohui Xin

Basalt fiber reinforced concrete (BFRC) has been widely utilized in various constructions such as buildings, large industrial floors, and highways, due to its excellent physical and mechanical properties, as well as low production cost. In order to address the influence of basic parameters such as fiber volume fraction (0.05∼0.40%), fiber length (12∼36 mm) of BF, and compressive strength (30, 40, and 50 MPa) of concrete on both physical and mechanical properties of BFRC including compressive strength, tensile and flexural strength, workability, and anti-dry-shrinkage cracking properties, a series of standard material tests were conducted. Experimental results indicated that clumping of fibers may occur at relatively higher fiber volume fraction resulting in mixing and casting problems. Based on experimental values of mechanical properties and anti-dry-shrinkage cracking resistance of BFRC, the reasonable basalt fiber length and fiber volume fractions are identified. The addition of a small amount of short basalt fibers can result in a considerable increase in both compressive strength and modulus of rupture (MoR) of BFRC and that the proposed fiber length and content are 12.0 mm and 0.10%∼0.15%, respectively. As the length of basalt fibers increases, the development of early shrinkage cracks decreases initially and then increases slowly and the optimal fiber length is 18.0 mm. Results of the study also indicated that early shrinkage cracks decrease with the increase of fiber volume fraction, and when the volume fraction of 0.20% is used, no cracks were observed. All the findings of the present study may provide reference for the material proportion design of BFRC.


2021 ◽  
Vol 16 (4) ◽  
pp. 169-176
Author(s):  
Xiaohu Luo

In order to improve the application effect of steel fiber reinforced concrete (SFRC) in road bridge construction, the mechanical properties of SFRC with different fiber content were analyzed. The SFRC specimens with 0%, 0.5%, 1%, 1.5% and 2% fiber content were designed, and the mechanical properties were tested. The results showed that the compressive strength first increased and then decreased with the increase of fiber content, and the maximum compressive strength of SFRC1.5 reached 40.86 MPa, increasing by 7.19%; the increase amplitude of tensile strength of SFRC1.5 was 73.04%, which was the most obvious; the flexural strength of SFRC increased with the increase of fiber content, and the flexural strength of SFRC2 was 9.78 MPa, increasing by 94.43%. It is concluded from the experimental results of a case study that SFRC1.5 presents the optimal overall mechanical properties and is more suitable for road bridge construction.


2019 ◽  
Vol 2019 ◽  
pp. 1-20 ◽  
Author(s):  
Ziming Cao ◽  
Qinyong Ma ◽  
Hongwei Wang

The purpose of this article is to evaluate the influence of basalt fiber content on the static-dynamic mechanical properties and microstructure of cement-fly ash-stabilized soil. The optimum mixed contents of cement and fly ash were obtained from the results of a series of physical and mechanical experiments. Based on the optimum mixed contents of cement and fly ash, the static-dynamic mechanical performances and microstructure of cement-fly ash-stabilized soil reinforced with basalt fiber were studied by means of the unconfined compression test, dynamic compression test (namely, SHPB test), and SEM test. The results demonstrated that the addition of basalt fiber in cement-fly ash-stabilized soil significantly enhanced the static-dynamic mechanical properties of stabilized soil. With basalt fiber content varying from 0% to 1.2%, the unconfined compressive strength, dynamic compressive strength, dynamic increase factor, and specific energy absorption of stabilized soil showed an upward trend first and a downward trend subsequently. The unconfined compressive strength, dynamic compressive strength, and energy absorption ability have a maximum improvement under the optimum basalt fiber content of 0.6%. In addition, the inclusion of basalt fiber can change the failure pattern of cement-fly ash-stabilized soil. The fractal dimension of broken fragments decreased gradually with the increasing basalt fiber content and increased correspondingly with the increasing impact loading pressure. With the basalt fiber content of 0.6%, a stable internal space structure produced inside stabilized soil. However, there are many fiber-fiber weak interfaces that appeared inside stabilized soil under the basalt fiber content of 1.2%. The microstructural observations can be considered as the good interpretations to verify the macroscopic mechanical characteristics.


2020 ◽  
Vol 14 (2) ◽  
pp. 6734-6742
Author(s):  
A. Syamsir ◽  
S. M. Mubin ◽  
N. M. Nor ◽  
V. Anggraini ◽  
S. Nagappan ◽  
...  

This study investigated the combine effect of 0.2 % drink cans and steel fibers with volume fractions of 0%, 0.5%, 1%, 1.5%, 2%, 2.5% and 3% to the mechanical properties and impact resistance of concrete. Hooked-end steel fiber with 30 mm and 0.75 mm length and diameter, respectively was selected for this study.  The drinks cans fiber were twisted manually in order to increase friction between fiber and concrete. The results of the experiment showed that the combination of steel fibers and drink cans fibers improved the strength performance of concrete, especially the compressive strength, flexural strength and indirect tensile strength. The results of the experiment showed that the combination of steel fibers and drink cans fibers improved the compressive strength, flexural strength and indirect tensile strength by 2.3, 7, and 2 times as compare to batch 1, respectively. Moreover, the impact resistance of fiber reinforced concrete has increase by 7 times as compared to non-fiber concretes. Moreover, the impact resistance of fiber reinforced concrete consistently gave better results as compared to non-fiber concretes. The fiber reinforced concrete turned more ductile as the dosage of fibers was increased and ductility started to decrease slightly after optimum fiber dosage was reached. It was found that concrete with combination of 2% steel and 0.2% drink cans fibers showed the highest compressive, split tensile, flexural as well as impact strength.    


2019 ◽  
Vol 9 (10) ◽  
pp. 2031 ◽  
Author(s):  
Hanbing Liu ◽  
Shiqi Liu ◽  
Shurong Wang ◽  
Xin Gao ◽  
Yafeng Gong

Basalt fibers are widely used in the modification of concrete materials due to its excellent mechanical properties and corrosion resistance. In this study, the basalt fibers were used to modify reactive powder concrete (RPC). The effect of four mix proportion parameters on the working and mechanical properties of basalt fiber reactive powder concrete (BFRPC) was evaluated by the response surface methodology (RSM). The fluidity, flexural and compressive strength were tested and evaluated. A statistically experimental model indicated that D (the silica fume to cement ratio) was the key of interactions between factors, affecting other factors and controlling properties of BFRPC. The increase in basalt fiber content had a remarkable effect on increasing the flexural and compressive strength when D = 0.2. The addition of basalt fiber obviously improved the mechanical properties of RPC. While when D = 0.4, the decrease of fiber content and the increase of quartz sand content could increase the compressive strength.


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