MARO® extension cones for bleed-free tensioning points. The hallmark of MARO cones is the double sealing ring in red.

If the tensioning point system is leaking, water and fine particles of concrete escape. This effect leads to bleeding at the tensioning point. The consequences range from circular discolouration around the tensioning point to fraying of the tensioning point’s edge and an exposed aggregate structure.

This is where the special features of the MARO® extension cones come into play: At the points where water can escape from the fresh concrete, the MARO® extension cone is sealed by a special sealing ring. The sealing ring is made of high-quality, closed-cell PE foam.

When the tensioning point is tightened, the sealing rings between the formwork and the cone are fully compressed into the cone.