Experimental Study on Improving Compressive Strength of Hexagonal Boron Nitride Reinforced Cement Composite

2020 ◽  
Vol 27 (6) ◽  
pp. 503-508
Author(s):  
Yomin Choi ◽  
Hyun‐Gyoo Shin
Keyword(s):  
Experimental Study ◽  
Compressive Strength ◽  
Boron Nitride ◽  
Hexagonal Boron Nitride ◽  
Cement Composite ◽  
Reinforced Cement

Effect of Boron Nitride on the Mechanical and Electrochemical Properties of Cement Composite

2015 ◽  
Author(s):  
Qinyue He ◽  
Xun Yu
Keyword(s):  
Corrosion Resistance ◽  
Boron Nitride ◽  
Electrochemical Properties ◽  
Hexagonal Boron Nitride ◽  
Water Solution ◽  
Cement Composite ◽  
Sodium Cholate ◽  
Ionic Surfactant ◽  
Cement Composites ◽  
Cement Concrete

Hexagonal boron nitride (h-BN) is well known for its unique properties, such as high thermal conductivity, excellent mechanical strength, high electrical insulating, and high chemical stability. This paper studies the effect of h-BN to the mechanical and electrochemical properties of cement concrete. Sodium cholate is used as an ionic surfactant to exfoliate h-BN and subsequently stabilize them in water solution. Different cement concrete samples with different doping levels of h-BN and different sizes of h-BN were prepared for comparisons. Also, steel fiber reinforced h-BN/cement concrete samples were also prepared. The results show that the addition of h-BN can improve the strength of cement composites, and the degree of reinforcement are influenced by the doping levels and feature size of h-BN. The corrosion resistance of h-BN/cement composites were also tested. Experiments results show that h-BN can enhance the corrosion resistance of cement composites.

scholarly journals Inhibition of Cracks on the Surface of Cement Mortar Using Estabragh Fibers

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Tahereh Soleimani ◽  
Ali Akbar Merati ◽  
Masoud Latifi ◽  
Ali Akbar Ramezanianpor
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Bending Strength ◽  
Cement Mortar ◽  
Physical And Mechanical Properties ◽  
Cement Composite ◽  
Cement Composites ◽  
Surface Cracks ◽  
Reinforced Cement ◽  
Mortar Matrix

The influence of adding Estabragh fibers into the cement composites of mortar on surface cracks and mechanical properties of mortar has been studied at various fiber proportions of 0.25%, 0.5%, and 0.75%. The mortar shrinkage was evaluated by counting the number of cracks and measuring the width of cracks on the surface of mortar specimens. Although the Estabragh fibers loss their strength in an alkali environment of cement composites, the ability of Estabragh fibers to bridge on the microcracks in the mortar matrix causes a decrease in the number of cracks and in their width on the surface of the mortar samples in comparison with the plain mortar. However, considering the mechanical properties of specimens such as bending strength and compressive strength, among all fiber proportions, only the specimens with 0.25% of Estabragh fiber performed better in all respects compared to the physical and mechanical properties of reinforced cement composite of mortar. Consequently, by adding 0.25% of Estabragh fibers to the cement mortar, a remarkable inhibition in crack generation on fiber-containing cement composite of mortar is achieved.

Study on the Properties of Oil Palm Trunk Fiber (OPTF) in Cement Composite

2013 ◽  
Vol 421 ◽  
pp. 395-400 ◽  
Author(s):  
Alida Abdullah ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
Hussin Kamarudin ◽  
Che Mohd Ruzaidi Ghazali ◽  
Mohd Arif Anuar Mohd Salleh ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Moisture Content ◽  
Water Absorption ◽  
Oil Palm ◽  
Cement Composite ◽  
Fiber Content ◽  
Percentage Increase ◽  
Fiber Reinforced ◽  
Oil Palm Trunk ◽  
Reinforced Cement

Properties of oil palm trunk fiber reinforced cement composite were investigated in this study. Oil palm trunk fiber was used to improve the properties of cement composite. It was found that increasing in oil palm trunk fiber content up to certain percentage increase the compressive strength and decrease the density of cement composite. Besides, the study also found that additional of excessive of oil palm trunk fiber in cement composite decrease the compressive strength and continues to increase the water absorption and moisture content hence decrease the density. From this study, it was found that 2 wt. % of fiber content was the optimum fiber content to give the highest compressive strength of 38.61 MPa.

Marcus-Hush Theory Revealed by Electron Tunneling Through Hexagonal Boron Nitride

2019 ◽  
Author(s):  
Matěj Velický ◽  
Sheng Hu ◽  
Colin R. Woods ◽  
Peter S. Toth ◽  
Viktor Zólyomi ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Boron Nitride ◽  
Electron Tunneling ◽  
Hexagonal Boron Nitride ◽  
Large Body ◽  
Liquid Solution ◽  
Limiting Current ◽  
Electron Transfer Rate Constant ◽  
Electrochemical Parameters ◽  
Voltammetric Measurements

Marcus-Hush theory of electron transfer is one of the pillars of modern electrochemistry with a large body of supporting experimental evidence presented to date. However, some predictions, such as the electrochemical behavior at microdisk electrodes, remain unverified. Herein, we present a study of electron tunneling across a hexagonal boron nitride barrier between a graphite electrode and redox levels in a liquid solution. This was achieved by the fabrication of microdisk electrodes with a typical diameter of 5 µm. Analysis of voltammetric measurements, using two common redox mediators, yielded several electrochemical parameters, including the electron transfer rate constant, limiting current, and transfer coefficient. They show a significant departure from the Butler-Volmer behavior in a clear manifestation of the Marcus-Hush theory of electron transfer. In addition, our system provides a novel experimental platform, which could be applied to address a number of scientific problems such as identification of reaction mechanisms, surface modification, or long-range electron transfer.

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