Microstructure, crack propagation, and mechanical properties of cement pastes containing high volumes of fly ashes

Journal Article · Tue Aug 01 04:00:00 EDT 1995 · Cement and Concrete Research

DOI:https://doi.org/10.1016/0008-8846(95)00109-P· OSTI ID:94391

Zhang, M H ^[1]

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1. CANMET, Ottawa, Ontario (Canada). Natural Resources Canada

This paper presents information on the effect of fly ashes on the microstructure of high volume fly ash (HVFA) pastes and how this affect the crack pattern and the stress-strain relationship. The HVFA pastes were prepared incorporating 58% of fly ashes. Fly ash particles appear to act as microaggregates in the pastes. Crack propagation generally deviates around the fly ash particles. Compared with that for the Portland cement paste of similar strength, the stress-strain curves for the HVFA pastes are less linear and begin to deviate at about 60--70% of the ultimate strength at 28 days. Based on these information, it was proposed that the HVFA paste may be considered as a composite material microscopically with fly ash particles as reactive microaggregates embedded in a matrix of hydration and reaction products. The effect of high volumes of fly ash on various properties of the concrete such as the modulus of elasticity, shrinkage and creep, as well as permeability were also discussed.

• OSTI ID: 94391
• Journal Information: Cement and Concrete Research, Journal Name: Cement and Concrete Research Journal Issue: 6 Vol. 25; ISSN 0008-8846; ISSN CCNRAI
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
36 MATERIALS SCIENCE
CEMENTS
CRACK PROPAGATION
FLY ASH
MECHANICAL PROPERTIES
MICROSTRUCTURE
STRAINS
STRESSES
WASTE PRODUCT UTILIZATION