Reinforcement Couplers

What are Reinforcement Coupler's

Reinforcement Coupler's are used to join Reinforcement bar's that are used in Reinforced concrete structures, as a replacement for conventional lapping method of joining Reinforcement bar's.

Mechanical Splice / Coupler's are mechanical connections between two pieces of reinforcing steel that enable the bars to behave in a manner similar to continuous lengths of reinforcing steel bars. Mechanical splice join rebar end-to-end, provides many advantages of a continuous piece of rebar.

Mechanical Splice system is used in connecting Reinforcement Bar of respective/ different diameter using the respective Coupler's as per applications and standards/criteria.

All Coupler Standards 

IS 16172 : 2014                 Click here..

ACI 318 / ACI 133              Click here..

BS 8110                            Click here..

ISO 15835 & NF 350-20      Click here..

CALTRANS                         Click here..

TEXAS DOT                       Click here..

Click Here!

Rebar Coupler Standards & Addressing the major Concern and Performance Parameters

Threads are been manufactured on Rebar's using set of installed machine 

(Discussed in Section : Machine)

Threading on Reinforcement bar's

Types of Thread

• Tapered Thread
• Parallel Thread

Tapered Thread - Taper Threads are those which have a slight taper. When mated together and tightened, the threads compress and get tightened at extreme ends. The mating Coupler thread should even have the same characteristic.

Parallel Thread - Parallel thread are Straight Thread which is have Parallel profile, and consistent diameter and thread profile is been maintained across the whole section of Coupler and Threaded rebar.

Parallel thread Mechanical Splice system are been designed and been manufactured for the connection of concrete reinforcement bars from 12 to 45mm and above diameter depending on the thread manufacturing machine on site.

The Process of Manufacturing thread on site involves 3 stages 

Cutting

Upsetting

Thread Manufacturing

Different Form and Process that are involved in thread manufacturing on rebars:

Process Type 1

• Cutting the Rebar
• Upsetting the Rebar  (Cold Forging directly on Rebar)
• Threading On Rebar  - using Thread Cutting Chaser

OR

Process Type 2

• Cutting the Rebar
• Peeling of Ribs on Rebars
• Upsetting the Rebar  (Cold Forging directly on Rebar)
• Threading On Rebar  - using Thread Cutting Chaser 

OR

Process Type 3

• Cutting the Rebar
• Peeling of Ribs on Rebars
• Roll Thread Manufacturing  - using Roll Thread Machine

Detailing on Process & Machine used for Manufacturing

Cutting of Rebar

Cutting of Rebar's as per the specified length as per the tolerance specified 

Machine used for Cutting Rebars

• Rebar Cutting Machine (Motorized stroke)
• Bandsaw Machine  

Upsetting of Rebar :

Upsetting means increasing the volume at the end part of Rebar by Cold forging the rebar, the diameter is increased up to specific length   

Machine Used for Upsetting

1. Cold forging machine for Rebars

Threading on Rebars :

Thread is been manufactured on a Rebar by special machine for manufacturing of threads on rebar using different chasers.

 

Advantages of using Couplers against  Conventional Lapping Method:

• Using Rebar Couplers eliminates Rebar Steel congestion.

• Minimizing Rebar wastage/scrap lead to the financial gain on projects.

• Easy to install & shortens construction cycle time

• No staggering of spliced rebars required

• No reduction of rebar cross section due to cold upsetting process

• Standard coupler used as position coupler.

• Type 2 Coupler suitable for seismic zones.

• Effective and economical alternative to conventional reinforcement lapping

• More reliable and more structural integrity than lapping splices because they no longer rely on the concrete for load transfer