scholarly journals Mechanical Properties of Carbon-Fiber RPC and Design Method of Carbon-Fiber Content under Different Curing Systems

Materials ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 3759 ◽  
Author(s):  
Xuejian Zhang ◽  
Lincai Ge ◽  
Yunlong Zhang ◽  
Jing Wang
Keyword(s):  
Carbon Fiber ◽  
Design Method ◽  
Fiber Content ◽  
Practical Application ◽  
X Ray Diffraction ◽  
Curing Conditions ◽  
Influencing Mechanism ◽  
Reactive Powder ◽  
Curing Compound ◽  
Curing Systems

Natural, standard, and compound curing are adopted to study the effect of different curing systems on the reinforcement of carbon fiber in reactive powder concrete (RPC). This work systematically studies the changes in RPC compressive and tensile strengths under different curing systems. Taking age, fiber content, and curing system as parameters, Scanning electron microscope (SEM) and X-ray diffraction (XRD) microscopic methods are used to study the influencing mechanism of carbon-fiber content and curing systems on RPC. The calculation methods of the RPC strength of different carbon-fiber contents are studied. Results show that the optimum carbon-fiber content of carbon-fiber RPC is 0.75% under the natural, standard, and compound curing conditions. In comparison with standard curing, compound curing can improve the early strength of carbon-fiber RPC and slightly affect the improvement of late strength. The strength is slightly lower in natural curing than in standard curing, but the former basically meets the requirements of the project and is beneficial for the practical application of this project. The calculation formula of 28-day compressive and splitting tensile strengths of carbon-fiber content from 0% to 0.75% is proposed to select the carbon-fiber content flexibly to satisfy different engineering requirements.

scholarly journals Study on Mix Proportion Optimization of Manufactured Sand RPC and Design Method of Steel Fiber Content under Different Curing Methods

Materials ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 1845 ◽  
Author(s):  
Chunling Zhong ◽  
Mo Liu ◽  
Yunlong Zhang ◽  
Jing Wang
Keyword(s):  
Steel Fiber ◽  
Design Method ◽  
Fiber Content ◽  
Orthogonal Experimental Design ◽  
Curing Conditions ◽  
Practical Applications ◽  
Manufactured Sand ◽  
Binder Ratio ◽  
Curing Methods ◽  
Reactive Powder

This study investigated four factors (water/binder ratio, silica fume, fly ash, and sand/binder ratio) using the orthogonal experimental design method to prepare the mix proportions of a manufactured sand reactive powder concrete (RPC) matrix to determine the optimal matrix mix proportions. On this basis, we assessed the compressive and splitting tensile strengths of different steel fiber contents under natural, standard, and compound curing conditions to develop an economical and reasonable RPC for various engineering requirements. A calculation method for the RPC strength of the steel fiber contents was evaluated. The results showed that the optimum steel fiber content for manufactured sand RPC is 4% under natural, standard, and compound curing conditions. Compared with standard curing, compound curing can improve the early strength of manufactured sand RPC but only has a small effect on the enhancement of late strength. Although the strength of natural curing is slightly lower than that of standard curing, it basically meets project requirements and is beneficial for practical applications. The calculation formula of 28-day compressive and splitting tensile strengths of manufactured sand RPC steel fiber at 0%–4% is proposed to meet the different engineering requirements and the flexible selection of steel fiber content.

Effects of Curing Systems on the Strength and Microstructure of Reactive Powder Concrete with Iron Tailing Sands

2014 ◽  
Vol 548-549 ◽  
pp. 247-253
Author(s):  
Zhi Gang Zhu ◽  
Bei Xing Li ◽  
Jin Cheng Liu ◽  
Xing Dong Lv
Keyword(s):  
Point Of View ◽  
Hot Water ◽  
Curing Temperature ◽  
Reactive Powder Concrete ◽  
Curing Time ◽  
Submicroscopic Structure ◽  
Curing Conditions ◽  
The Difference ◽  
Reactive Powder ◽  
Curing Systems

To produce 130MPa reactive powder concrete with iron tailing sands as aggregation in an economic hot curing system, the effects of curing temperature, curing time and curing conditions on the reactive powder concrete was studied, the reasons of the strength of reactive powder concrete in different curing systems has the difference from the submicroscopic structure point of view was analyzed. The results show that use 90°C hot water to cure reactive powder concrete for 48h can lead it’s 28 day compressive strength reaches 140MPa, the flexural strength reaches 28MPa.

scholarly journals Reactive Powder Concrete Mix Ratio and Steel Fiber Content Optimization under Different Curing Conditions

Materials ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 3615 ◽  
Author(s):  
Yunlong Zhang ◽  
Bin Wu ◽  
Jing Wang ◽  
Mo Liu ◽  
Xu Zhang
Keyword(s):  
Tensile Strength ◽  
Steel Fiber ◽  
Orthogonal Experiment ◽  
Fiber Content ◽  
Reactive Powder Concrete ◽  
Mixture Ratio ◽  
Curing Conditions ◽  
Compressive Performance ◽  
Binder Ratio ◽  
Reactive Powder

In this paper, a practical reactive powder concrete mixture ratio is created on the basis of an orthogonal experiment. Previous studies have combined the compressive and splitting tensile strengths of four categories of reactive powder concrete (RPC) for major materials. These categories include water/binder ratio, silica fume volume content, sand/binder ratio, and dosage of fly ash volume. The optimal mixing proportion of each factor was determined by analyzing the compressive strength of the RPC matrix. For this purpose, steel fiber was used as a reinforcing agent. The compressive and splitting tensile strength test results of steel fiber RPC were analyzed by comparing compound, standard, and natural curing. This was conducted to explore the improvement effect of different steel fiber contents on compressive performance, especially tensile strength of the RPC matrix. According to the results, the optimal steel fiber content was found to be 4% under the three curing conditions. The effect of compound curing on early strength was found to be greater in RPC than by natural or standard curing. However, the effect of late improvement is not obvious. Although standard curing is slightly stronger than natural curing, the performance under the latter can still meet engineering requirements.

scholarly journals Effect of Hybrid Steel-Basalt Fiber on Behaviors of Manufactured Sand RPC and Fiber Content Optimization Using Center Composite Design

2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Yunlong Zhang ◽  
Jiahui Liu ◽  
Jing Wang ◽  
Bin Wu
Keyword(s):  
Compressive Strength ◽  
Flexural Strength ◽  
Response Surface ◽  
Basalt Fiber ◽  
Fiber Content ◽  
Surface Model ◽  
Basalt Fibers ◽  
Curing Conditions ◽  
Manufactured Sand ◽  
Reactive Powder

The mechanical properties and workability of manufactured sand reactive powder concrete (RPC) mixed with steel and basalt fibers were studied using the response surface method. The central composite design was used to explore the 7-day and 28-day compressive strength, flexural strength, and workability of different amounts of mixed fiber-manufactured sand RPC. Results showed that when the steel fiber content was less than 2.5%, mixing basalt fibers can significantly improve the flexural strength and flexural-compressive ratio of RPC. The relationship equations of the two fibers with the 28-day compressive strength, flexural strength, and flexural-compressive ratio of the manufactured sand RPC were obtained through the response surface model. The model proved to be reliable according to the analysis of variance. The content of the two fibers was optimized by multiobjective optimization technology, and the optimal content of the mixed fiber-manufactured sand RPC under standard curing conditions was verified.

scholarly journals Improving flexural and dielectric properties of carbon fiber epoxy composite laminates reinforced with carbon nanotubes interlayer using electrospray deposition

2020 ◽  
Vol 9 (1) ◽  
pp. 1170-1182
Author(s):  
Muhammad Razlan Zakaria ◽  
Hazizan Md Akil ◽  
Mohd Firdaus Omar ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
Aslina Anjang Ab Rahman ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Dielectric Properties ◽  
Carbon Fiber ◽  
Composite Laminates ◽  
Epoxy Composite ◽  
Flexural Modulus ◽  
X Ray Diffraction ◽  
Electrospray Deposition ◽  
Ft Ir ◽  
Carbon Fiber Epoxy

AbstractThe electrospray deposition method was used to deposit carbon nanotubes (CNT) onto the surfaces of woven carbon fiber (CF) to produce woven hybrid carbon fiber–carbon nanotubes (CF–CNT). Extreme high-resolution field emission scanning electron microscopy (XHR-FESEM), X-ray diffraction (XRD), Raman spectroscopy and Fourier transform infrared spectroscopy (FT-IR) were used to analyze the woven hybrid CF–CNT. The results demonstrated that CNT was successfully and homogenously distributed on the woven CF surface. Woven hybrid CF–CNT epoxy composite laminates were then prepared and compared with woven CF epoxy composite laminates in terms of their flexural and dielectric properties. The results indicated that the flexural strength, flexural modulus and dielectric constant of the woven hybrid CF–CNT epoxy composite laminates were improved up to 19, 27 and 25%, respectively, compared with the woven CF epoxy composite laminates.

scholarly journals Absorption and Strength Properties of Short Carbon Fiber Reinforced Mortar Composite

Buildings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 300
Author(s):  
Md. Safiuddin ◽  
George Abdel-Sayed ◽  
Nataliya Hearn
Keyword(s):  
Tensile Strength ◽  
Carbon Fiber ◽  
Water Absorption ◽  
Carbon Fibers ◽  
Strength Properties ◽  
Fiber Content ◽  
Test Results ◽  
Air Content ◽  
Entrapped Air ◽  
Short Carbon

This paper presents the water absorption and strength properties of short carbon fiber reinforced mortar (CFRM) composite. Four CFRM composites with 1%, 2%, 3%, and 4% short pitch-based carbon fibers were produced in this study. Normal Portland cement mortar (NCPM) was also prepared for use as the control mortar. The freshly mixed mortar composites were tested for workability, wet density, and entrapped air content. In addition, the hardened mortar composites were examined for compressive strength, splitting tensile strength, flexural strength, and water absorption at the ages of 7 and 28 days. The effects of different carbon fiber contents on the tested properties were observed. Test results showed that the incorporation of carbon fibers decreased the workability and wet density, but increased the entrapped air content in mortar composite. Most interestingly, the compressive strength of CFRM composite increased up to 3% carbon fiber content and then it declined significantly for 4% fiber content, depending on the workability and compaction of the mortar. In contrast, the splitting tensile strength and flexural strength of the CFRM composite increased for all fiber contents due to the greater cracking resistance and improved bond strength of the carbon fibers in the mortar. The presence of short pitch-based carbon fibers significantly strengthened the mortar by bridging the microcracks, resisting the propagation of these minute cracks, and impeding the growth of macrocracks. Furthermore, the water absorption of CFRM composite decreased up to 3% carbon fiber content and then it increased substantially for 4% fiber content, depending on the entrapped air content of the mortar. The overall test results suggest that the mortar with 3% carbon fibers is the optimum CFRM composite based on the tested properties.

Development and Application of New Design Method by High-Strength Composite Material - Fusing of Optimum Strength Evaluation and Product Design

2013 ◽  
Vol 372 ◽  
pp. 17-20 ◽  
Author(s):  
Haruhiko Iida ◽  
Hidetoshi Sakamoto ◽  
Yoshifumi Ohbuchi
Keyword(s):  
Composite Material ◽  
Carbon Fiber ◽  
Product Design ◽  
Design Method ◽  
Target Material ◽  
High Strength ◽  
Fiber Glass ◽  
Strength Evaluation ◽  
Fiber Reinforced Materials ◽  
Manufacturing Methods

The purpose of this research is the development of new design method for integrating the optimum strength evaluation and the product design which can make the best use of material's characteristics obtained by the experiment and the analysis. Further we do design using high-strength composite material with this developed concept which is different from conventional design. First, to establish this design method of high-strength materials, we examined these materials characteristics and manufacturing methods and the commercialized products. As this research target material, we focus the fiber reinforced materials such as composite with carbon fiber, glass fiber and aramid fiber. Above all, we marked the carbon fiber which has the high specific tensile strength, wear resistance, heat conductivity and conductance. Here, we introduce the fundamental design concept which makes the best use of the design with enough strength.

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