Screw connection
MODIX coupling system
Bolted reinforcement joints with annular gap control
The MODIX screw-type coupler from Peikko is a mechanical coupling for reinforcing bars with a metric thread and a circumferential annular gap for easy visual inspection. The coupler bar and the connecting bar are pressed together and screwed into place, creating a continuous reinforcement that can absorb tensile and compressive forces just like a single, unjoined bar. When the annular gap is completely closed, the required tightening torque has been achieved and the joint is approved – without the need for complex torque measurement.
The system comprises standard, reducing, positioning, combination and welded sleeves, as well as end anchors, and thus covers virtually all common connection and joint details in reinforced concrete construction.
Typical applications
Peikko MODIX – practical, flexible and cost-effective
Peikko MODIX is used wherever a conventional lap joint would require too much space, material or coordination of reinforcement. Typical situations include column joints in rectangular and circular columns, particularly where there is a high degree of reinforcement and limited concrete cover. MODIX is also frequently used at wall-to-slab and wall-to-beam connections, for example in slipform or climbing formwork with shear-bearing joints.
Check at a glance
MODIX on the construction site
Peikko’s MODIX screw-in couplers are installed using standard tools; no special equipment or complex measuring technology is required. The integrated ring gap control allows for a simple visual inspection: if the gap is closed, the joint is correctly tightened and the intended load-bearing capacity is ensured. This provides you with an easy-to-install, quickly verifiable solution for reinforcement joints – ideal for both construction sites and precast plants.
Get a quote now – give us a call and let us put together your custom MODIX package.
Advantages
The key benefits at a glance
- 100% load-bearing capacity, equivalent to a non-jointed reinforcing bar under static loads.
- Flexible joint positions and connection details within the component can be freely selected.
- Simple installation by screwing alone – no special tools required.
- Quick and reliable control of the annular gap.
- Short lead times and efficient processes thanks to decentralised production within the SÜLZLE Stahlpartner network
MODIX components and accessories at a glance
- MODIX SM Standard Sleeve: Connection of bars of the same diameter; one bar can be rotated.
- MODIX RM Reducing Sleeve: Connection of adjacent bars of different diameters (e.g. 20 to 16 mm).
- MODIX PM Positioning Sleeve: Joint solution where neither bar can be rotated and axial tolerances are limited.
- MODIX KM Combination Sleeve: Transition from reinforcing steel to standard metric bolts for steel connections.
- MODIX EM End Anchoring Sleeve: Plate plus functional washer as an alternative to hook or stirrup anchors.
- MODIX AM Weld-on Sleeve: Connection of reinforcing bars to steel components via a weld-on sleeve.
- Accessories: Screw plugs, round caps, nail plates and magnetic plates for thread protection and formwork fixing
Structural behaviour and design verification
- In the design state, the joint behaves like an unjoined bar, i.e. it can withstand 100% of the tensile and compressive forces under predominantly static loading.
- It may also be used under non-predominantly static and impact loading, for example in structures subject to high loading rates.
Planning and detailing
With the MODIX screw connection, joint points are no longer restricted to long lap lengths but can be positioned freely within the structural element, making it much easier to plan reinforcement routing and connection details. At the same time, a uniform system covers identical and adjacent diameters, straight or curved bars, as well as connections to steel components, so that different connection scenarios can be addressed using a consistent solution concept.
On-site installation
- Installation using standard tools, without the need for specialised machinery or a power supply.
- Quality assurance based on a single parameter: closed annular gap = connection fully tightened.
- Protective caps and accessories prevent damage and corrosion to the threads during storage, transport and the initial concrete pouring phase
Cost-effectiveness
- Eliminating long lap joints reduces the amount of steel required and relieves the joint area of the need for double reinforcement layers.
- Slimmer cross-sections and joint areas that are easier to concrete can reduce formwork, concrete and labour costs.
- Decentralised production by steel partners reduces transport costs and increases availability on the project.
Standards, approvals and quality
MODIX holds a building authority approval in Germany (DIBt Berlin) for applications in accordance with DIN EN 1992. It also holds national approvals in countries including the Netherlands, Finland, Austria, Hungary, Poland, Russia and Slovakia; details are provided centrally by Peikko. The connection is fully verifiable for the load cases specified in the system; although individual special components (e.g. combination and end anchor sleeves) are not covered by the European Technical Assessment, they are manufactured to the same quality standards.