Abstract
In order to study the mechanical properties of basalt fiber reinforced ultra-fine fly ash concrete (BFUFARC), the effects of ultra-fine fly ash (UFA) content, basalt fiber content, basalt fiber length and water reducing agent content on the compressive strength, splitting tensile strength and flexural strength of the composite material were studied through experimental and theoretical analysis. Also, a scanning electron microscope (SEM) was employed to analyze the mesoscopic structure in the fracture surface of composite material specimens at magnifications of 500 and 3500. Besides, the energy release rate (Gc) and surface free energy (γs) of crack tip cracking on BFUFARC in different basalt fiber content were studied from the perspective of fracture mechanics. Further, the cracking resistance, reinforcement, and toughening mechanisms of basalt fibers on concrete substrate were revealed by surface free energy of BFUFARC. The experimental results indicated that basalt fiber content is the main influence factor on the splitting tensile strength of BFUFARC. In case that fiber content increased from 0 to 0.3%, the concrete surface free energy at the tip of single-sided crack showed a trend of increased at first and then decreased. The surface free energy reached at maximum, about 3.59 × 10-5 MN/m. During the process of increasing fiber content from 0 to 0.1%, Gc-2γs showed a gradually decreasing trend. As a result, an appropriate amount of basalt fiber can play a preventing cracking role by increasing the concrete surface free energy, further effectively improve the concrete splitting tensile performance.
Key Words
BFUFARC; crack tip cracking; energy release rate; mesoscopic structure; surface free energy; theoretical analysis
Address
(1) Yu H. Yang, Sheng J. Jin, Chang C. Shi, Wen P. Ma:
School of Materials Science and Engineering, School of Architecture and Civil Engineering, Shenyang University of Technology, No.111, Shenliao West Street, Shenyang Economic and Technological Development Zone, Shenyang 110870, Liaoning Province, the People's Republic of China;
(2) Chang C. Shi:
Department of Civil Engineering, Hebei University of Water Resources and Electric Engineering, No.1 Chongqing Road, Nanhuan Middle Road Street, Yunhe District, Cangzhou 061001, Hebei Province, the People's Republic of China;
(3) Jia K. Zhao:
School of Civil Engineering, Inner Mongolia University of Science and Technology, No.7 Alding Street, Baotou City, Inner Mongolia Autonomous Region, Baotou 014010, Liaoning Province, the People's Republic of China;
(4) Jia K. Zhao:
School of Civil Engineering, Shenyang Jianzhu University, No. 9, Hunnan East Road, Hunnan New Area, Shenyang 110168, Liaoning Province, the People's Republic of China.
Abstract
As the first part of the body that strikes the ground during running, sports shoes are especially important for improving performance and reducing injuries. The use of new nanotechnology materials in the shoe's sole that can affect the movement angle of the foot and the ground reaction forces during running has not been reported yet. It is important to consider the material of the sole of the shoe since it determines the long-term performance of sports shoes, including their comfort while walking, running, and jumping. Running performance can be improved by polymer foam that provides good support with low energy dissipation (low energy dissipation). Running shoes have a midsole made of ethylene propylene copolymer (EPP) foam. The mechanical properties of EPP foam are, however, low. To improve the mechanical performance of EPP, conventional mineral fillers are commonly used, but these fillers sacrifice energy return. In this study, to improve the magnificence of physical education training with nanotechnology, carbon nanotubes (CNTs) derived from recycled plastics were prepared by catalytic chemical vapor deposition and used as nucleating and reinforcing agents. As a result of the results, the physical, mechanical, and dynamic response properties of EPP foam combined with CNT and zinc oxide nanoparticles were significantly improved. When CNT was added to the nanocomposites with a weight percentage of less than 0.5 wt%, the wear resistance, physical properties, dynamic stiffness, compressive strength, and rebound properties of EPP foams were significantly improved.
Address
(1) Jinyan Ge, Yunbin Li:
Physical Education Department, Xi'an Jiaotong University, Xi'an 710049, Shaanxi, P.R. China;
(2) Yuxin Hong:
Schools of Materials Science and Engineering, Xi'an Jiaotong University, Xi'an 710049, Shaanxi, P.R. China;
(3) Rongtian Zeng:
School of Nuclear Science and Technology, Xi'an Jiaotong University, Xi'an 710049, Shaanxi, P.R. China;
(4) Mostafa Habibi:
Faculty of Architecture and Urbanism, UTE University, Calle Rumipamba S/N and Bourgeois, Quito, Ecuador;
(5) Mostafa Habibi:
Department of Biomaterials, Saveetha Dental College and Hospital, Saveetha Institute of Medical and Technical Sciences, Chennai 600 077, India;
(6) Mostafa Habibi:
Institute of Research and Development, Duy Tan University, Da Nang 550000, Viet Nam;
(7) Mostafa Habibi:
Faculty of Electrical-Electronic Engineering, Duy Tan University, Da Nang 550000, Viet Nam;
(8) Mostafa Habibi:
Center of Excellence in Design, Robotics, and Automation, Department of Mechanical Engineering, Sharif University of Technology, Azadi Avenue, P.O. Box 11365-9567, Tehran, Iran.
Abstract
Using industrial wastes and construction and demolition (C&D) wastes is potentially advantageous for concrete production in terms of sustainability improvement. In this paper, a sustainable Self-Compacting Concrete (SCC) made with industrial wastes and C&D wastes was proposed by considerably replacing natural counterparts with recycled coarse aggregates (RCAs) and supplementary cementitious materials (SCMs) (i.e., Fly ash (FA), ground granulated blast furnace slag (GGBS) and silica fume (SF)). A total of 12 SCC mixes with various RCAs and different combination SCMs were prepared, which comprise binary, ternary and quaternary mixes. The mechanical properties in terms of compressive strength and static elasticity modulus of recycled aggregates (RA-SCC) mixes were determined and analyzed. Microstructural study was implemented to analyze the reason of improvement on mechanical properties. By means of life cycle assessment (LCA) method, the environmental impacts of RA-SCC with various RCAs and SCMs were quantified, analyzed and compared in the system boundary of "cradle-to-gate". In addition, the comparison of LCA results with respect to mechanical properties was conducted. The results demonstrate that the addition of proposed combination SCMs leads to significant improvement in mechanical properties of quaternary RA-SCC mixes with FA, GGBS and SF. Furthermore, quaternary RA-SCC mixes emit lowest environmental burdens without compromising mechanical properties. Thus, using the combination of FA, GGBS and SF as cement substitution to manufacture RA-SCC significantly improves the sustainability of SCC by minimizing the depletion of cement and non-renewable natural resources.
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