Field Application of Hydro-Demolition and Dry-Mix Shotcrete for Repairing the Understructure of Bridge Deck

Abstract

Since it is impossible to reconstruct the top level that has collapsed, a formwork is constructed to squeegee mortar or spray mortar, and repair kits are being used in Korea to chip away the damaged concrete of the bridge deck structure. In Korea, a technique called hydro-demolition replaces water blasting and water jetting by using high-pressure water to remove not only asphalt but also old and broken concrete. Additionally, dry materials including cement, aggregate, and additives are carried via the inside of a hose to the field using compressed air, where they meet water and are ejected at a high rate of speed. This technique is known as dry mix shotcrete. Using the devised automatic hydraulic dismantling technology and high-performance dry-mix shotcrete, field application results are discussed in this study.

Keywords

• hydro-demolition
• shotcrete
• overhead shooting
• repair
• field application