Tie requirements for rebar lap splices per ACI
Tie requirements for rebar lap splices per ACI
(OP)
Can anyone tell me which ACI document defines how rebar lap splices are required to be tied (i.e. how many ties, spacing, etc.), assuming there is a requirement?
Also, what is the difference between a regular lap splice and "development" splice where the bars are not tied?
Also, what is the difference between a regular lap splice and "development" splice where the bars are not tied?






RE: Tie requirements for rebar lap splices per ACI
Development length is the length required to embed a bar into concrete to develop it. A lap splice is the length required to overlap bars to transfer load from one bar to the other.
ACI318 has requirements.
RE: Tie requirements for rebar lap splices per ACI
Mike McCann
MMC Engineering
http://mmcengineering.tripod.com
RE: Tie requirements for rebar lap splices per ACI
As an aside: Reference ACI 318-05. The general development length equation has a parameter that represents the contribution of confining reinforcement. ACI gives two-tier approach for calculating development lengths. Section 12.2.2 is a simplified approach. Per this section stirrups or ties are not required per say, but if you want to take advantage of the presence of ties then they have to conform to the code minimum.
Section 12.2.3 represents the general development length equation. Here transverse reinforcement index is calculated based on area of ties, spacing of ties, and the number of bars being developed or spliced. The development lengths, and in turn the splice lengths, can be significantly reduced by taking advantage of the presence of the confining reinforcement. The designer has an option here.
RE: Tie requirements for rebar lap splices per ACI
RE: Tie requirements for rebar lap splices per ACI
RE: Tie requirements for rebar lap splices per ACI
In general, the bars should stay in place, or deflect under the weight of workers and construction loads (like wheelbarrows) and then rebound to the required position when the load is removed. Tying of bars, in all cases, is "temporary" and ONLY required for maintaining location during construction and in wet concrete. Wire ties have no effect on design, or on installed performance.
Caution, sales pitch: For field personnel, CRSI's "Placing Reinforcing Bars" covers most placing issues encountered by placers and inspectors.
RE: Tie requirements for rebar lap splices per ACI
So when I overlap bars to transfer tension, they don't have to be tied? For instance, can I lap bars but have a couple inches of space between them and still transfer the tension?
RE: Tie requirements for rebar lap splices per ACI
RE: Tie requirements for rebar lap splices per ACI
I think this is similar to the approach I use when developing anchor rods with high tension loads.
RE: Tie requirements for rebar lap splices per ACI
Ok, I will check that section out tomorrow when I get to the office. Thanks!
RE: Tie requirements for rebar lap splices per ACI
Exactly. I usually apply the same logic. I just wasn't sure if it was "codified."
RE: Tie requirements for rebar lap splices per ACI
Moreover noncontact lap splices are permitted only in flexural members. My understandng is that noncontact lap splices would not be applicable in (direct) tension members.