Thursday, February 09, 2017

IS:5525- Detailing of reinforcement in reinforced concrete works

This standard deals with the general requirements of detailing of reinforcement in reinforced concrete structures.

  • According to it, all reinforcement bars used in structures shall be suitably designated & numbered both in drawing & in schedule.
  • The use of the same type of line for the same purpose considerably enhances the clarity & usefulness of the drawing. 
  • Different structural members of a structure shall be marked using symbols, abbreviations & notations.
  • A key framing plan shall be prepared to a convenient scale & the two axes marked, one side with alphabets A, B, C etc & other with numbers. The same key framing plan may be used for all floors if the arrangement of beams is same at different floors.
  • Columns & Foundations shall be specified by grid arrangement giving reference to the floor.
  • Beams, Slabs & Lintels, Tie Beams shall be numbered from left hand top corner.
  • Scales shall be so chosen to bring out the details clearly. No general recommendations can be given in this respect, although commonly used scales are given below as examples:
  • Structural drawing prepared by the designer shall show detail of reinforcement & all other information needed for detailing the reinforcement. A separate structural drawing supplemented by bar bending schedule should preferably be made for each unit. For small structures, entire requirements may be handled as one unit.
  • Schedules:
Mark & location of member
Drawing reference
No of Member
Bar Type
Bar No.
Bar Size
Detailed (Dimensioned sketch)
Cutting Bar Length
No. of Bars per Member
Total no. of Bars
Total weight of bars
  • Congestion of steel should be avoided at points where members intersect.  
  • When a member has a break in its direction so that the reinforcement in tension tends to separate from the body of the concrete, special anchorage shall be provided and shown in detail.
  • Splices:  Where beams and girders require bars longer than carried in stock, the splices in the bars shall be made where the stress in the bar is minimum, that is, at the point of inflection.
  • Where the tops of column bars are less than 1.8 above the top of footings or pedestals, the bars shall extend into footing or pedestal, and dowels shall not be used unless specifically indicated by the designer.
      a) Plan      - 1:100, 1:5
      b) Elevation - 1:5, 1:30

The reinforcement of slabs, beams and many other parts of structure may be effectively shown on working drawings or in tabular form, known as a schedule. The schedule should also include special notes on bending and any special information, such as requirement of laps, two layers of steel. For many structures detailed on a single sheet, the schedule may be placed in the upper left corner of the drawing. For larger structures, requiring more than one drawing the complete schedule may appear on the last sheet of the details.