Strength Development and Drying Shrinkage of Steam-Cured Concrete Containing PFBC Coal Ash

Title: Strength Development and Drying Shrinkage of Steam-Cured Concrete Containing PFBC Coal Ash
Author(s): Tanaka
Paper category : conference
Book title: International RILEM Conference on the Use of Recycled Materials in Building and Structures
Editor(s): E. Vázquez, Ch. F. Hendriks and G.M.T. Janssen
Print-ISBN: 2-912143-52-7
e-ISBN: 2912143756
Publisher: RILEM Publications SARL
Publication year: 2004
Pages: 890 - 898
Total Pages: 9
Nb references: 5
Language: English

Abstract: A pressurized fluidized bed combustion (PFBC) thermal power plant has been constructed
in Japan in order to enhance power-generating efficiency as well as to reduce environmental
load. Coal ash produced from this type of power plant (PFBC coal ash) contains large
amounts of CaO, SO3, and small amount of SiO2.
In order to utilize PFBC coal ash to structural concrete like prefabricated concrete
products as an mineral admixture, strength development and drying shrinkage of concrete
containing PFBC coal ash (PFBC concrete) cured by steam of 60 °C are investigated
experimentally relating its microstructure and hydrated products. Water to binder (W/B) ratios
of concrete are 0.30 and 0.45, and their replacement ratios of the ash are 0.0 and 0.3,
respectively.
The compressive strength of PFBC concrete were 20% lower than that of normal concrete
independent of W/B at early ages. However, the former exceeded the latter at and after 28
days for W/B = 0.30 and reached almost the same strength as the latter at 1 year for W/B =
0.45. One of the reasons for these results might be explained by production of ettringite which
reduce pore volume in the size over 0.1 µm in diameter, especially in case of W/B = 0.30 as
pozzolanic reaction was not significantly observed.
Drying shrinkage of PFBC concrete was comparable with that of normal concrete, while
measurement in full sized hollow girder without arrangement of steel bars showed the
contribution of PFBC coal ash to reducing autogenous shrinkage.

Online publication: 2004-09-29
Publication type : full_text
Public price (Euros): 0.00
doi: 10.1617/2912143756.098