Bond of Reinforcement to Superplasticized Concrete


  • The International Concrete Abstracts Portal is an ACI led collaboration with leading technical organizations from within the international concrete industry and offers the most comprehensive collection of published concrete abstracts.

International Concrete Abstracts Portal


Title: Bond of Reinforcement to Superplasticized Concrete

Author(s): Barie B. Brettmann, David Darwin, and Rex C. Donahey

Publication: Journal Proceedings

Volume: 83

Issue: 1

Appears on pages(s): 98-107

Keywords: bond (concrete to reinforcement); concrete construction; consolidation; cover, plasticizers; pullout tests; reinforced concrete; reinforcing steels; vibration; water-reducing agents

Date: 1/1/1986

The effects of superplasticizers on concrete-steel bond strength were studied. Key variables were degree of consolidation, concrete slump, both with and without a superplasticizer, concrete temperature, and bar position. No. 8 deformed reinforcing bars were used with a 2 in. (51 mm) cover and a 10 in. (254 mm) bonded length. Concrete slumps ranged from 1 3/4 in. to 9 in. (44 to 229 mm). Three specimen depths were used. All specimens were modified cantilever beam specimens. The experimental results show that high-slump superplasticized concrete provides a lower bond strength than low-slump concrete of the same strength. Vibration of high-slump concrete increases the bond strength compared to high-slump concrete without vibration. The current ACI top bar requirements appear to be unconservative for top-cast bars with less than 12 in. (305 mm) of concrete below the bar and are possibly over-conservative for nontop-cast bars with more than 12 in. (305 mm) of concrete below the bar when low-slump concrete is used.