Concrete-to-concrete bond strength. Influence of the roughness of the substrate...

• Author(s): Júlio, Eduardo N. B. S. ; Branco, Fernando A. B. ; Silva, Vítor D.
• Date: 2004
• Persistent ID: http://hdl.handle.net/10316/3982
• Origin: Estudo Geral - Universidade de Coimbra
• Subject(s): Concrete; Roughness; Strength
• Document Type: Article
• Language: English

Description

An experimental study was performed to evaluate the bond strength between two concrete layers, for different techniques for increasing the roughness of the substrate surface. In a total of 25 slant shear specimens and 25 pull-off specimens the substrate surface was prepared by wire-brushing; sand-blasting; chipping with a light jackhammer; or were left as-cast against steel formwork. Three months later, the new concrete was added. Pull-off tests were performed to evaluate the bond strength in tension. Slant shear tests were conducted to quantify the bond strength in shear. Analysis of results indicated that: the highest value of bond strength was achieved with sand-blasting; pull-off tests are adequate to estimate the bond strength in situ; and pre-wetting the substrate surface does not seem to influence the bond strength. http://www.sciencedirect.com/science/article/B6V2G-4CMYMDN-3/1/b64e1833c354a3d441d24c410cb979d3