REINFORCEMENT SPLICING – AS PER IS 456 -2000

 

REINFORCEMENT SPLICING – AS PER IS 456 -2000

It Is recommended that splices (Lap) in flexural member should not be at sections where the bending moment is more than 50 percent of the moment of resistance; and not more than half the bars shall be spliced at a section.

Where more than one-half of the bars are spliced at a section or where splices are made at point of maximum stress, special precaution shall be taken, such as increasing the length of lap and/or using spirals or closely-spaced stirrups around the length of the splice.

Notes:-

1.     Lap splices shall not be used for bars larger than 36 mm; for larger diameters, bars may be welded; in cases where welding is not practicable, lapping of bars larger than 36 mm may be permitted, in which case additional spirals should be provided around the lapped bars.

2.     Lap splices shall be considered as staggered if the centre to centre distance of the splices is not less than 1.3 times the lap length.

3.     Lap length including anchorage value of hooks for bars in flexural tension shall be Ld. Or  30d  whichever is greater and for direct tension shall be 2Ld  Or  30d  whichever is greater.

4.   The straight length of the lap shall not be Jess than 15d , or 200 mm.

5.     The lap length in compression shall be equal to the development length in compression, but not less than 24d.

6.     When bars of two different diameters are to be spliced, the lap length shall be calculated on the basis of diameter of the smaller bar.

7.    Splices in tension members shall be enclosed in spirals made of bars not less than 6 mm diameter with pitch not more than 100mm.




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