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Splices per ACI 318-19 with ideCAD

How does ideCAD define lap splice lengths according to ACI 318-19?


  • Minimum clear spacing between the contact lap splice and adjacent splices or bars is controlled automatically according to 25.2.1.

  • Tension lap splice length lst for deformed bars and deformed wires in tension is controlled with Table 25.5.2.1.

  • Compression lap splice length lsc is controlled automatically according to 25.5.5.


Symbols

As = area of nonprestressed longitudinal tension reinforcement, in.2
ld = development length in tension of deformed bar, deformed wire, plain and deformed welded wire reinforcement, or pretensioned strand, in.
ldc = development length in compression of deformed bars and deformed wire, in.
lsc = compression lap splice length, in.
lst = tension lap splice length, in.
Ktr = transverse reinforcement index, in.
db = nominal diameter of bar, wire, or prestressing strand, in
f'c = specified comprehensive strength of concrete, psi
fy = specified yield strength of nonprestressed reinforcement, psi


General

Lap splices couldn’t be done for rebars larger than No. 11, according to 25.5.1.1. Minimum clear spacing between the contact lap splice and adjacent splices or bars is controlled according to 25.2.1.Minimum Spacing of Reinforcement per ACI 318-19 with ideCAD

The transverse center-to-center spacing of spliced bars does not exceed the lesser of 1/5 the required lap splice length and 6 in. for noncontact splices, according to 25.5.1.3.

Transverse reinforcement is provided such that Ktr is not smaller than 0.5db, for bars with fy≥80000 psi, according to 25.5.1.5.

Lap splice lengths of deformed bars and deformed wires in tension

Tension lap splice length lst for deformed bars and deformed wires in tension is controlled with Table 25.5.2.1.

As,provided/As,required over length of splice

Maximum percent of As spliced within required lap length

Splice type

lst


≥ 2.0

50

Class A

Greater of:

1.0ld and 12 in.

100

Class B


Greater of:


1.3ld and 12 in.

< 2.0

All cases

Class B

Lap splice lengths of deformed bars in compression

Compression lap splice length lsc of No. 11 or smaller deformed bars in compression is calculated according to the rules below:

(a) For fy≤60000 psi : lsc is the longer of 0.0005fydb and 12 in.
(b) For 60000 psi < fy ≤ 80000 psi: lsc is the longer of (0.0009fy – 24)db and 12 in.
(c) For fy > 80000 psi, lsc is the longer of (0.0009fy – 24)db and lst calculated in accordance with 25.5.2.1.
For f'c < 3000 psi, the length of the lap is automatically increased by one-third.

Compression lap splices are not used for bars larger than No. 11.

Compression lap splices of No. 14 or No. 18 bars to No. 11 or smaller bars are permitted. Where bars of different sizes are lap spliced in compression, lsc is the longer ldc of the larger bar calculated in accordance with 25.4.9.1, and lsc of the smaller bar is calculated in accordance with 25.5.5.1 as appropriate.


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