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.