Title:
Effect of Crack Control in Mortars Containing Polypropylene Fibers on the Corrosion of Steel in a Cementitious Matrix
Author(s):
M. A. Sanjuan, C. Andrade, and A. Bentur
Publication:
Materials Journal
Volume:
94
Issue:
2
Appears on pages(s):
134-141
Keywords:
corrosion; cracking (fracturing); mortars (material);
polypropylene fibers; reinforcing steels;
DOI:
10.14359/294
Date:
3/1/1997
Abstract:
Low-volume polypropylene fiber reinforcement is known to be effective in reducing plastic shrinkage cracking. In the present work this advantage of fiber reinforcement is evaluated in terms of its influence on the corrosion of steel in concrete, which is sensitive to the presence of cracks in the matrix. Mortar specimens with reinforcing bars were exposed to restrained shrinkage conditions by drying immediately after casting. Some of the matrixes were reinforced with low-volume polypropylene fibers. After the initial curing the specimens were held in corrosive conditions in contact with chloride solutions and the corrosion rate of the bars was monitored by electrochemical means and visual observations of crack development. No clear-cut correlation could be established between cracking induced at early age and the corrosion rate when analyzing each bar individually within each specimen. However, when addressing the general trends between the various specimens tested it could be concluded that for systems of the same matrix composition the ones with fibers seemed to crack less initially, and later had somewhat lower corrosion rates as measured by the linear polarization method. In addition, the fiber reinforced specimens demonstrated an ability for self-healing of cracks under the corrosive environment, whereas the plain mortar specimens under the same conditions showed a tendency for increase in the width of the cracks formed at early age.