BBR VT CONA CMM Single internal post-tensioning system

The European approved CONA® CMM Single system is an advanced generation of monostrand unbonded or bonded post-tensioning and is the only one of its type on the international market today. The system has been optimized to feature lighter anchorages and offer designers the smallest available tendon center spacing and concrete edge distance for stressing at the very low concrete strength of 18/22MPa. It also includes features which accelerate installation and thus reduce material and labor costs.

Greased & sheathed monostrand or cement grouted plastic duct

It is mainly used for post-tensioning thin slabs, where small post-tensioning units are required - such as in suspended flat slabs of car parks, apartment buildings, commercial office developments and shopping centers, as well as in slab-on-grade applications in distribution warehouses. Further applications of CONA CMM Single are hospitals, hotels, sporting venues and bridge decks. BBR Network Members offer design of slab PT structures and have sound engineering knowledge in order to maximize the benefits for all stakeholders.

Anchorage configuration

The main components in the anchor zone of the CONA CMM Single system are the wedge, monolithic anchorage and an individual threaded transition tube. The anchoring of the strand and load transfer to the concrete is done with one and the same unit, allowing for a high economy, small tendon center spacing and concrete edge distance at the anchorage, as well as application of the full post-tensioning load at very low concrete strengths.

Intermediate anchorage and monolithic couplers

If a structure is to be concreted and post-tensioned in sections the CONA CMM Single tendons can be installed with compact intermediate anchorages at construction joints allowing the use of continuous strand. At the construction joints, the tendons are stressed after the first section of the concrete structure has been cast while the remaining length of the tendon is kept neatly coiled, ready to be installed in the adjacent section of the structure.

For situations where use of the intermediate anchorage is not practical, a monolithic Type T coupling anchorage – with an integrated, preinstalled wedge – is available. This can be easily coupled to a normal anchor head using a coupling thread. CONA CMM Single tendons can also be coupled using a proprietary Type H sleeve coupler.

Intermediate Anchorage
Coupler T
Coupler H
BBR VT Plastic Duct (round)

Corrosion protection

For CONA CMM Single unbonded applications, the monostrands are greased/waxed and individually sheathed in a factory with a continuously extruded HDPE sheathing. In bonded applications, the individual strand is enclosed in a corrugated round BBR VT Plastic Duct or steel duct and is filled with a high performance BBR grout.

CONA CMM approvals

European Technical Approvals

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CONA CMM CAD drawings

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The Ultimate Design Guide Volume 2: System Specifications
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