DEXTRA REBAR COUPLER SYSTEMS

Reinforced concrete design and construction practice has historically focuses on the use of lap splicing as a method of transferring load between reinforcement bars.

This relies on the load being transferred from one rebar, through the surrounding concrete and into the adjacent lapped rebar. However, the lapping of reinforcement is not always the most appropriate splicing method and there are many situations where the use of mechanical rebar couplers is more desirable from a design perspective, more convenient from a construction perspective, or both.

Rebar coupler systems, sometimes also known as mechanical splices, are used as an alternative to traditional lap splices in concrete. They transmit the rebar load directly from one rebar to another without relying on concrete bond, concrete strength, or the condition of the concrete surrounding the rebar and coupler.

Advantages

There are many well-documented advantages to using rebar coupler systems. These include:

2.1 Rebar Continuity

Reinforced concrete design codes of practice, including IS 456 , assume that the detailing, quality of materials and workmanship is such that the transmission of forces in a lap splice from one rebar to the other is assured. However, if the bond between the concrete and the rebar is lost, possibly because of concrete cracking, deterioration, poor on site workmanship, rebar corrosion and subsequent spalling etc. then the rebar lap splice may fail. Rebar couplers do not rely on concrete bond and therefore they create more reliable rebar continuity.

2.2 Avoidance of Transverse Splitting Forces

Many structural concrete codes of practice recommend the use of rebar couplers as an alternative to lapping, particularly for large rebar diameters where splitting and dowel action forces can be significant. IS 456 states “lap splices shall not be used for bars larger than 36mm” and goes on to say that if there is no alternative, then lapping of large diameter bars should be accompanied by additional spirals along the lap length to act as confinement reinforcement.

2.3 Reduction of Rebar Congestion