TITLE:
Hardening Properties of Foamed Concrete with Circulating Fluidized Bed Boiler Ash, Blast Furnace Slag, and Desulfurization Gypsum as the Binder
AUTHORS:
Seunghyun Na, Woonggeol Lee, Myongshin Song
KEYWORDS:
Circulating Fluidized Bed Boiler Ash, Compressive Strength, Foamed Concrete, Heavy Metal Ions Immobilization, Field Test
JOURNAL NAME:
Open Journal of Civil Engineering,
Vol.11 No.3,
September
13,
2021
ABSTRACT: Recently,
a large amount of circulating fluidized bed boiler ash (CFBA) and desulfurization
gypsum (DSG) has been produced, and it is essential to develop technology to
utilize them. These materials have CaO and SO3, which are considered to be a stimulant for blast furnace slag (BFS). This study
presents an experimental investigation of the compressive strength and heavy
metal ions immobilization properties of cement-free materials comprising CFBA,
BFS, and DSG. The feasibility of manufacturing foamed concrete using these
materials was examined, and field test of foamed concrete was conducted.
Experimentally, the flow, compressive strength, and heavy metal ions
concentration were evaluated via inductively coupled plasma atomic emission
spectroscopy (ICP-AES) of the paste and foamed concrete. The experimental investigation
revealed the self-healing hardening ability of fluidized bed boiler ash. In
addition, the compressive strength was increased with the increasing
replacement rates of BFS and DSG in the CFBA paste, and the compressive
strength of 14.6 - 17.2 MPa was recorded over 28 days of curing. From the result obtained,
the feasibility of manufacturing foamed concrete with a foam volume of 120 L, incorporating the aforementioned materials, is confirmed. It was
also found that after 28 days of age, a 7.9-MPa compressive strength of the
foamed concrete was attained, and heavy metal ions elution in this foamed
concrete was also significantly reduced. Therefore, CFBA, BFS, and DSG could be
used as a binder for the foamed concrete.