Title:
Ruskin Dam Spillway Shotcrete Assessed
Author(s):
Lihe Zhang, Mazin Ezzet, Natalya Shanahan, Dudley R. Morgan, and A.P. Sukumar
Publication:
Concrete International
Volume:
33
Issue:
2
Appears on pages(s):
37-43
Keywords:
shotcrete, overlay, impact echo, condition assessment
DOI:
Date:
2/1/2011
Abstract:
The Ruskin Dam is an 80-year-old hydro-electric mass concrete structure located on the Stave River in British Columbia, Canada. Dry-mix shotcrete patch repairs were carried out some 56 years ago, and 37 years ago the entire face of the concrete spillway and stepped abutment were surfaced with dry-mix shotcrete. Results of a systematic investigation conducted to evaluate the shotcrete faced spillway are summarized. The condition assessment included visual mapping of defects such as cracks, spalls and erosion damage, augmented by hammer- and chain drag sounding. This was complemented by impact echo testing, with calibration by extraction of cores by diamond core drilling. Extracted shotcrete/concrete cores were tested for compressive strength, density, boiled absorption, and volume of permeable voids. In addition, petrographic analysis was conducted on selected cores to characterize quality and durability of the shotcrete and concrete.