TITLE:
Development of Eco-Friendly Deconstruction Technologies for Recycling Construction Waste
AUTHORS:
Myungkwan Lim, Heesup Choi, Hyeonggil Choi, Ryoma Kitagaki, Takahumi Noguchi
KEYWORDS:
Recycling, Deconstruction, Heat Induction, Ease to Scrap, Weakening
JOURNAL NAME:
Journal of Environmental Protection,
Vol.5 No.7,
May
30,
2014
ABSTRACT: Recently,
the intended use and required performance of buildings are rapidly changing
with advances in scientific technology and globalization. Furthermore, given the
population growth in semi-developed and developing countries, economic growth, increasing
waste, and increasing amounts of energy consumption, the industry requires the
development of efficient methods to deconstruct old buildings by reducing waste
and saving as much energy as possible during periods of urban redevelopment and
maintenance. In general, either an ordinary breaker or a hydraulic breaker is
used to deconstruct reinforced concrete buildings. This deconstruction method
has the ability to shorten the construction period compared to the other
methods, but it is difficult to separate the debris that gets mixed when the
deconstruction is completed, as it is a rough construction method that uses
large equipment. This study develops a technology that can be used to selectively
heat, separate, and deconstruct the steel reinforcement inside reinforced
concrete, treating the reinforcement as a conductive resistor and applying
high-frequency induction heating to the reinforced concrete structure.
Specifically, this study verifies the temperature characteristics of deformed
bars inside reinforced concrete, the occurrence of cracks due to thermal
fracture of the deformed bars, and chemical and physical weakening of concrete
by thermal conduction on the surface of steel reinforcement using the
high-frequency induction heating technology. Furthermore, this study considers
the extent of concrete weakening in the heating range of appropriate energy and
carries out a technical review of the stages that would be actually applied.
This technology involves low noise and low pollution levels, and it increases
the collection rate of steel reinforcement inside separated reinforced concrete
members and the recycling rate of construction wastes; thus, its use is
expected to reduce the energy consumption by minimizing secondary processing.