Title:
Influence of fly ash from co-combustion of coal and biomass on scaling resistance of concrete
Author(s):
M. Kosior-Kazberuk, D. Józwiak-Niedzwiedzka
Publication:
KILW
Volume:
56
Issue:
3
Appears on pages(s):
239-254
Keywords:
concrete, durability, fly ash from co-combustion of coal and biomass, scaling resistance,microstructure
DOI:
Date:
7/1/2010
Abstract:
Industrial utilization of fly ash from various kinds of fuel plays an important role in the environmentally
clean and cost effective power production. The primary market for fly ash utilization
is as a pozzolanic addition in concrete production. The paper concerns the concretes containing
fly ash called Fly Ash from Biomass (FAB) from co-combustion of hard coal and wood biomass
(wood chips). Characterization of the fly ash was carried on by means of X-ray diffractometry
and E-SEM/EDS analysis. The results of laboratory studies undertaken to evaluate the influence of
FAB on concrete resistance to surface scaling due to cyclic freezing and thawing in the presence
of NaCl solution were presented. The tests were carried out for concretes containing up to 25% of
fly ash related to cement mass. Additionally, the microstructure of air-voids was described.
It was concluded that the FAB has significant effect on concrete freeze/thaw durability. The replacement
of cement by fly ash from co-combustion progressively transformed the concrete microstructure
into less resistant against freeze/thaw cycles and excessive dosage (over 15%) may
dangerously increase the scaling.