Why use Couplers?
Reinforcing bar couplers have many advantages over lapped joints because
they:
- Allow coupled bars to perform as an integral unit
- Minimize steel congestion, particularly when using large diameter bar
- Reduce the tonnage of bar, which reduces the overall weight of the structure
- Permit continuity of construction
- improve speed of construction
- are suitable for remedial / repair applications
Materials
The source of material is Parallel thread coupler, which to be get tested on particular frequency basis.
- Raw materials of coupler: – Should be complied with ASTM-E-415 & BS-970.
- Pull out test: – Should be complied with ACI-318
Cutting
- The end of rebar is cut to make it flat
Forging
Threading
- Parallel threads are cut into the enlarged end of the rebar by rotating chasers.
Splicing
- The rebars are then connected using mechanical splices
Assembly Steps
Step 1: Prepare the 1st stage Bar
- The thread protection caps are correctly fitted.
Step 2: Position the continuation bars
- Remove the thread protections from the first stage bars and bring the continuation bars in butt‐to‐butt contact .
- The couplers are fully engaged on the continuation bars.
Step 3: Joint The Bars
- Hand screw the coupler out of the continuation bar and onto the first stage bar. (A wrench may be used if it makes the operation easier).
- Full engagement of the thread is sufficient to develop the full tensile strength of the splice.
Step 4: Lock the splices
- Use a stilson or pipe wrench on the continuation bar. No specific torque amount is required
- Locking the splice ensures that its permanent elongation meets the code requirement.
