Title:
Use of Silica-Fume Concrete to Repair Abrasion-Erosion Damage in the Kinzua Dam Stilling Basin
Author(s):
Terence C. Holland, Anton Krysa,
Mark D. Luther, and Tony C. Liu
Publication:
Symposium Paper
Volume:
91
Issue:
Appears on pages(s):
841-864
Keywords:
abrasion resistance; admixtures; damage; dams; erosion;
high-strength concretes; repairs; silica: stilling basins.
DOI:
10.14359/10100
Date:
2/1/1986
Abstract:
The stilling basin of Kinzua Dam on the Allegheny River in western Pennsylvania has experienced severe abrasion-erosion damage since the structure was put into operation in 1967. The basin was repaired in 1973-74 using a steel fiber-reinforced concrete overlay. Deterioration continued to the extent that repairs were again necessary in 1983. A laboratory program was undertaken to evaluate the abrasion-erosion resistance of several concrete mixtures proposed for the 1983 repairs. This program showed that high-strength concrete made with silica fume and limestone aggregates available near the project site would provide suitable abrasion-erosion resistance at a reasonable price. The Corps of Engineers, owner of the structure, required potential suppliers of silica fume to conduct full-sized placements to demonstrate that this concrete could be made and placed outside the laboratory. Based upon these demonstrations and the laboratory program, the repair concrete was specified with a compressive strength of 86 MPa (12,500 psi) at 28 days as a means of obtaining the required abrasion-erosion resistance. Approximately 1500 m* (2000 yd3) of 250-mm (9 3/4-in.) slump concrete were placed using silica fume delivered as a slurry that included water-reducing admixtures. The average 28-day compressive strength was over 90 MPa (13,000 psi). Diver inspection of the concrete after one year in service, including a period with a very large volume of debris in the stilling basin, has indicated that the silica-fume concrete is performing as intended.