What is the Columns reinforcement splice length according to ACI, BS, SBC?

It depends types of loading(tension, compression) strenght of concrete, steel, methods of splicing i.e. mechanical splice, welded splice, end bearing etc.

A comprehensive detail is included in ACI, BS & BSC

ACI = Amercan Concrete Institude

BS = British specification ( British Standards)

SBC = Saudi Building Code

In normal method, conservative formula is used for splices which is applicable for all codes.i.e.

Splice Length = 50 * dia of steel bar.

e.g. for 20mm dia bar

Splice length =50*20 =1000mm=1m

for further detail, please refer to

BS 81101997

ACI 12.17.2 — Lap splices in columns

50 times dia of bar

dia of bar : maximum dia used in the column