scholarly journals Acceleration mechanism of nonisothermal microwave heating on strength development of mortar

2021 ◽  
pp. 114765
Author(s):  
Shuangxin Li ◽  
Xiaojian Gao
2014 ◽  
Vol 17 (5) ◽  
pp. 365-372 ◽  
Author(s):  
Tae Hoon Koh ◽  
Seon Keun Hwang ◽  
Do Young Moon ◽  
Jung Hoon Yoo ◽  
Jin Woo Song ◽  
...  

Materials ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1113 ◽  
Author(s):  
Hyeonggil Choi ◽  
Taehoon Koh ◽  
Heesup Choi ◽  
Yukio Hama

The purpose of this study is to evaluate the temperature distribution, strength development, porosity, scanning electron microscopy observation, shrinkage, and surface properties of concrete in order to apply microwave heat curing to the precast method and to analyze the CO2 emissions and economic feasibility of microwave heat curing. The heating of a steel form by microwave heating enabled concrete to be efficiently cured at a temperature within a range of ±5 °C. After the curing, demolding strength could be cleared through the densification of the concrete by decreasing the porosity of the concrete. Microwave heat curing exhibited excellent performance compared to conventional steam curing in terms of efficient temperature control, occurrence of cracks due to shrinkage, surface condition of concrete after curing, economic efficiency, and CO2 emissions. However, verification and supplementation based on actual data are necessary so that environments applicable to the various sizes and shapes of forms can be prepared.


2008 ◽  
Author(s):  
Sarah A. Schnitker ◽  
Justin L. Barrett ◽  
Robert A. Emmons

Long-term experience of application of a method of electric heating by heating wires of the monolithic concrete and reinforced concrete structures erected in winter conditions is analyzed. This method, developed by the author of the article, took a dominant position on the construction sites due to the simplicity and efficiency in comparison with the mass applied in those years, the method of electric heating of concrete with steel round and strip electrodes. The data on labor intensity, material and energy costs in comparison with the method of rod electric heating are presented. Step-by-step technological operations on preparatory works and electric heating of monolithic structures with the use of extensive hands-on material, which formed the basis for the development of technological regulations, supplemented by a number of new proposals to improve the technology of works, are concretized. In order to work out the optimal mode of heat treatment, the studies of the concrete thermal conductivity factor in the process of its heating and strength development were carried out. The method for calculation of the basic parameters of concrete electric heating is presented. For simplification of calculations, for a wide contingent of masters, superintendents and technical personnel, the nomogram , making it possible with sufficient accuracy under the construction conditions to calculate the necessary heating parameters, was developed. The necessity of grounding the heating wire remaining in the concrete to reduce the harmful effect of magnetic radiation from various appliances and household appliances on the human body is noted.


2012 ◽  
Vol 2 (3) ◽  
pp. 102-104 ◽  
Author(s):  
Suthar Sunil B ◽  
◽  
Dr. (Smt.) B. K. Shah Dr. (Smt.) B. K. Shah

2002 ◽  
Author(s):  
Kazuo Aoki ◽  
Phadungsak Ratanadecho ◽  
Takashi Mikawa ◽  
Masatoshi Akahori

2002 ◽  
Author(s):  
Arnaud Jacotin ◽  
Elodie Bachelier ◽  
Francois Liousse ◽  
Pierre Millan

2001 ◽  
Vol 50 (8) ◽  
pp. 807-811
Author(s):  
Harutake IMOTO ◽  
Etsuo SAKAI ◽  
Akinori NAKAMURA ◽  
Masaki DAIMON

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