Title: Application of Fibrillated Polypropylene Fibers for Restraint of Plastic Shrinkage Cracking in Silica Fume Concrete

Author(s): Ziad Bayasi and Marc McIntyre

Publication: Materials Journal

Volume: 99

Issue: 4

Appears on pages(s): 337-344

Keywords: bleeding; crack; finishing; plastic shrinkage; silica fume

DOI: 10.14359/12215

Date: 7/1/2002

Abstract:
A review of the literature and an experimental research investigation are reported herein. The mechanism of plastic shrinkage cracking, as well as the effects of fibrillated polypropylene fibers and silica fume, are discussed. Fibers restrain cracks by promoting water retention, setting acceleration, increasing tensile strain capacity, and controlling crack growth of fresh concrete. By increasing the number of menisci capillaries and water demand, silica fume increases the plastic shrinkage cracking of fresh concrete. The use of 0.1% volume fraction of fibrillated polypropylene fibers was found to be effective in shrinkage crack reduction of concretes with a silica fume content of 0 or 5%. The use of a 0.3% volume of fibrillated polypropylene fibers was found to be successful in combatting plastic shrinkage cracking in concrete with a 10% silica fume content.