Influence of bar chairs, spacers and blocks on concrete structures

Much of the time, concrete durability problems are a result of the lack of protective concrete cover to reinforcement with the subsequent corrosion causing the concrete to crack, break down and decay. This lack of cover can often be attributed to the improper placement of the reinforcement, which can be overcome by the proper selection and use of bar chairs, spacers and mortar blocks. Though such items seem small and inconsequential, they are in fact vital when endeavouring to make durable reinforced concrete and correctly place reinforcement to design requirements. Maintenance of correct cover to reinforcement for durability purposes will reduce future costs of repairs and maintenance. Improper placement of the reinforcement in the concrete reduces the design intent and consequently the life and the capacity of the structure. This is often the result of the incorrect selection, installation and use of bar chairs and spacers. The aim of this project was to review and assess the use of concrete reinforcing spacers and supports in construction. A literature search was carried out on publications, covering bar chairs, spacers and blocks, followed by a subsequent review of the material located. Some direct contact was made with interested parties, such as other state road authorities and private enterprise. The report concludes that: (1) there are no standards or codes covering the manufacture, testing and use of bar chairs and spacers in Australia; (2) the industry may produce and use whatever items they choose, such that the buyer must beware; (3) introducing national guidelines will optimise durability, and consequently the life of many concrete structures will be extended.

• Corporate Authors:

  South Australia. Road Transport Agency. Materials Technology Research and Development Program

  Adelaide, South Australia   
• Authors:
  • Mackey, G
  • Januszke, R
• Publication Date: 1995-10

Language

• English

Media Info

• Pagination: 21p
• Serial:
  • Issue Number: 100-1

Subject/Index Terms

• TRT Terms: Concrete; Construction management; Durability; Materials tests; Reinforced concrete; Structural design; Test procedures
• Uncontrolled Terms: Code of practice
• ATRI Terms: Code of practice; Concrete; Construction method; Durability; Material testing; Reinforced concrete; Structural design; Test method
• Subject Areas: Construction;

Filing Info

• Accession Number: 01435186
• Record Type: Publication
• Source Agency: ARRB
• Files: ATRI
• Created Date: Aug 24 2012 6:51PM