Title: High Content of Fly Ash (Class F) in Extruded Cementitious Composites

Author(s): Alva Peled, Michele F. Cyr, and Surendra P. Shah

Publication: Materials Journal

Volume: 97

Issue: 5

Appears on pages(s): 509-517

Keywords: durability; fly ash; rheology

DOI: 10.14359/9283

Date: 9/1/2000

Abstract:
This paper presents mechanical properties and durability of extruded fiber-reinforced cement composites that contain a high percentage of Class F fly ash. The fly ash was examined as a replacement for cement in a plain cement matrix and composites containing polyvinyl alcohol (PVA), glass, acrylic (PAN), polypropylene (PP), or cellulose fibers. Accelerated aging was used to study the effect of fly ash on the durability of the different systems. It is shown that fly ash improves the flexural performance of the extruded composite. The extent of this improvement varies with fiber type. PAN, glass, and cellulose fibers were most affected by the use of fly ash. The greatest improvement in both flexural strength and ductility was obtained for 28-day moist-cured com-posites containing PAN fibers when as much as 70%, by volume, of the cement was replaced with fly ash. In this case, a five-fold increase in toughness and an approximately 20% improvement in strength were observed for steam-cured composites.