Title:
Influence of Material Ductility on Performance of Concrete Repair
Author(s):
Mo Li and Victor C. Li
Publication:
Materials Journal
Volume:
106
Issue:
5
Appears on pages(s):
419-428
Keywords:
cracking; ductility; durability; interface delamination; repair; shrinkage; simulation.
DOI:
10.14359/51663142
Date:
9/1/2009
Abstract:
The lack of durability in concrete repairs induces premature repair deterioration. Drying shrinkage of "new" repair material restrained by "old" concrete substrate results in repair layer cracking, and interface delamination between the repair and the concrete substrate. This paper investigates a material solution to these common repair failures. A high-early-strength engineered cementitious composite (HES-ECC) developed for concrete repair is employed for this study. The HES-ECC possesses high early-age strength (over 47 MPa [6885 psi] in 7 days) and high tensile strain capacity several hundred times that of normal concrete or fiberreinforced concrete (FRC). Experimental and numerical studies on a layered repair system were conducted to verify that the high ductility of HES-ECC can relieve shrinkage-induced stresses in the repair layer and at the repair/old concrete interface, thereby simultaneously suppressing large repair surface cracks and interface delamination. Detailed results of these studies are reported in this paper.