TMS

1 Development Background

Reinforcing bar joints used in the construction of containment structure of nuclear power plant have mainly two types; sleeve joints having a filler metal of iron joints (hereinafter called "Cadweld") and cold rolled parallel screw joints (hereinafter called "parallel thread joints") for prevailing use. Cadweld needs to trim the material in foreign countries requiring specialized equipment and skilled workers which results in the poor economy and workability.
In case of parallel thread joints the workability compared to Cadweld has been improved the parallel threaded joints improved but the parallel thread joints cannot be free from the defects of initial slip due to the gap between the male thread of rebar and the female thread of screw occurring at the time of performance test since the parallel structure of the screw tightening joints are fastened tightly in one direction by the repulsive force of the tightening direction.
As this is not appropriate for seismic design and construction of containment structure of nuclear power plant given that safety is a top priority, we have developed the harbinger tapered & threaded screw rebar joints showing the excellent clamping force and seismic performance

2 Types Of TMS

3 Features Of TMS

Features No.1

Thread machining using cold roll formed method

Screws are machined using cold roll formed method for tight structuring of rebar screw threads and excellent mechanical properties.

Features No.2

Sleeve's clamping force and earthquake-proof performance are reinforced

As technology using threaded screws, it boasts of excellent coupling performance between female and male threaded rods and the floor.
The threaded rod friction area is wide that it boasts of excellent and powerful clamping force against loosening from vibration.

Features No.3

Screw's bordering parts has excellent strength

The rebar screw's bordering parts is in the tapered form, and there is no sharp change of the threaded section. When the sleeves are clamped, the stress is dispersed. Therefore, the screw bordering parts are very strong and the incomplete screw parts of rebar can be covered with sleeves without external exposure of screw threads.

Features No.4

It has excellent constructability and working safety using TMS method

The rebar screws and sleeves are threaded for easy finding of the center. As a result, the constructability and working safety are excellent. The standard sleeves are structured in all-in-one that one can save on production cost.
Double-lined screws can be applied for efficient and speedy construction.

Features No.5

Verified earthquake-proof performance of TMS

Through the static / dynamic experimental study on reinforced concrete structures to which TMS is applied, compared the load carrying capacity and earthquake-proof performance of rebar concrete structures, wherein rebar without splices and TMS have been applied, and confirmed that there is no performance difference in either the rebar continuity or behavioral characteristics

4 Configuration Of TMS

Standard Type

Standard-Transition Type

Position Type

(※ Position type: a sleeve used when a rebar cannot be rotated)

Position-Transition Type

(※ Position-transition type: a sleeve used when a rebar cannot be rotated and when splicing rebars with different standards)