Properties of concrete containing wood/coal fly ash mixtures

Conference · Thu Jul 01 04:00:00 EDT 1999

OSTI ID:20082241

Boylan, D M; Larrimore, C L; Fouad, F

Utilities are increasingly interested in co-firing wood with coal in existing pulverized coal units. The co-firing technology is a means of developing a relatively low-cost renewable energy resource, as well as of supporting customers and community by making energy with biomass that might otherwise have been land-filled. However, recent changes in the ASTM C618 standard for fly ash as cement replacement restrict the definition of fly ash that includes non-coal sources. As a result, wood co-firing could affect the market for the fly ash, reducing ash sales revenue, increasing ash disposal costs, and overall substantially increasing the cost of the co-firing technology. In order to address concerns about the effect of wood ash/coal ash mixtures on concrete properties, a study was conducted by University of Alabama at Birmingham, Southern Company, EPRI, and the State of Alabama. This study compared the effects on properties of concrete made with fly ash from coal and made with fly ash from co-firing up to 30% wood with coal. Fly ashes from three plants were used, with two of the ashes from actual co-firing experience and the third an artificial blend of wood and coal ash. Concrete test cylinders were made of several cement/fly ash mixes, and enough were made to allow testing periodically over a one year time period. Test measurements included workability, setting time, air content, compressive and flexural strength, rapid chloride permeability and freeze thaw. It was concluded on the basis of these tests that the wood ash content had no detrimental effect on the plastic and hardened properties of the concrete.

• Research Organization: Southern Co. (US)
• OSTI ID: 20082241
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
09 BIOMASS FUELS
20 FOSSIL-FUELED POWER PLANTS
36 MATERIALS SCIENCE
COAL
COCOMBUSTION
CONCRETES
FLY ASH
MECHANICAL PROPERTIES
PHYSICAL PROPERTIES
WASTE PRODUCT UTILIZATION
WOOD FUELS