Aggregate liberation from concrete by flow cavitation

✍ Scribed by A.W. Momber

• Publisher: Elsevier Science
• Year: 2004
• Tongue: English
• Weight: 912 KB
• Volume: 74
• Category: Article
• ISSN: 0301-7516
• DOI: 10.1016/j.minpro.2003.10.004

✦ Synopsis

Short-time cavitation erosion was utilized to selectively liberate aggregate particles from concrete substrates. Five different concrete mixtures with compressive strengths between 23 and 80 MPa were subjected to erosion in a flow cavitation chamber. Cavitation erosion with an exposure time as low as 10 s generated measurable material removal. Erosion rate depended mainly on material texture (density), and showed only a weak dependence on fracture toughness and compressive strength. The erosion mode was intergranular in most cases, thus matrix and aggregate could be separated with separation efficiencies between 46% and 90%. A fracture mechanics model was developed to explain the selectivity effects in cavitation erosion.