Title: Effect of Low Addition Rates of Polypropylene Fibers on Plastic Shrinkage Cracking and Mechanical Properties of Concrete

Author(s): N. S. Berke and M. P. Dallaire

Publication: Symposium Paper

Volume: 142

Issue:

Appears on pages(s): 19-42

Keywords: compressive strength; cracking (fracturing); flexural strength; fiber reinforced concretes; freeze-thaw durability; impact strength; mechanical properties; modulus of elasticity; polypropylene fibers; shrinkage; Materials Research

DOI: 10.14359/1179

Date: 1/1/1994

Abstract:
Discusses the results of a study of the effects of low addition rates of polypropylene fibers on plastic shrinkage cracking and mechanical properties of concrete. Addition rates of 0.75, 1.5, and 3.0 lb/yd 3 (0.05 to 0.2 volume percent) were used, with fiber lengths that varied between 0.5 and 2.0 in. Relatively low addition rates were shown to significantly reduce plastic shrinkage cracking. Freezing and thawing durability was not affected by the addition of fibers. Modulus of elasticity, flexural strength, and compressive strength were not changed by the addition rates of polypropylene fibers studied. At the addition rates of polypropylene fibers studied, ASTM Method C 1116 Level II I 5 toughness index values were satisfied. The drop weight hammer test, as described in ACI Committee 544, was utilized for determining the impact resistance of fiber reinforced concrete. Drop weight hammer impact results for fiber reinforced concrete at the fiber addition rate of 3.0 lb/yd 3 demonstrated a significant improvement.