MANUFACTURING ACCURACY IN CONNECTION WITH BENDING OF REINFORCEMENT

A source material, which can form a basis for tolerance in connection with bending of reinforcement, has previously been lacking. Such a material, which derives from reinforcement shops, building sites and precast concrete element factories, is presented in this report. The analyses of the material are mainly based on the mean value and standard deviation for measurement series of dimensional and angular deviations. These analyses have shown that the factors bar diameter, shape and size have a significant influence on the standard deviation as regards dimensional deviations. This is not the case for the mean value. On the other hand, factors such as motivation and knowledge as well as inspection and information, which can be regarded as dependent on and affecting the operator, mainly affect the mean value and to a lesser extent the standard deviation. The main conclusions and recommendations of the report are the following: (1) the tolerance limits which are said to apply to ready cut and bent reinforcement are frequently exceeded. There are indications that the tolerance limits with regard to the concrete cover specified in the concrete regulations often are exceeded; (2) inspection and information are important aids in the work devoted to satisfactory manufacturing accuracy; (3) bending of reinforcement is to a considerable extent an operator controlled work. Development work should be devoted to making bending less operator dependent; (4) flexible tolerance setting should be introduced. Tolerance ranges for dimensional deviations should be dependent on bar diameter, shape and size. As regards angular deviations and deviations for cutting, the tolerance range should be independent of these factors. (Author/TRRL)

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/03466906
• Corporate Authors:

  Cement and Concrete Research Institute

  Drottning Kristinas Vaeg 26
  Stockholm 70,   Sweden 
• Authors:
  • Hjort, B
• Publication Date: 1984

Media Info

• Features: Figures; Photos; References; Tables;
• Pagination: 288 p.
• Serial:
  • CBI FORSK/RES
  • Publisher: Cement and Concrete Research Institute
  • ISSN: 0346-6906

Subject/Index Terms

• TRT Terms: Accuracy; Angularity; Bending; Concrete; Engineering tolerance; Manufactures; Manufacturing; Material reinforcement; Mathematical analysis; Measurement; Metal bars; Precast concrete; Quality control; Reinforcing materials; Size; Statistical deviation; Statistical trends; Surveillance; Theses
• Uncontrolled Terms: Quality
• Old TRIS Terms: Angles (Geometry); Deviation; Tolerance (Stat); Tolerances
• ITRD Terms: 6471: Analysis (math); 3461: Bar; 4755: Concrete; 5586: Deflection; 9014: Dimension; 6440: Error; 3647: Manufacture; 6136: Measurement; 9063: Quality; 3471: Reinforcement (in mater); 6532: Significance (stat); 9101: Surveillance; 8597: Thesis
• Subject Areas: Geotechnology; Highways; Materials; I34: Steels and Metals;

Filing Info

• Accession Number: 00396255
• Record Type: Publication
• Source Agency: Swedish National Road and Transport Research Institute (VTI)
• Report/Paper Numbers: FO5.84 Monograph
• Files: ITRD, TRIS
• Created Date: Jan 31 1986 12:00AM