Preventing plastic shrinkage cracks: micro fibres in practice
The first hours after pouring are critical. Why plastic shrinkage cracks occur, and how 0.6–1.0 kg/m³ of micro fibres prevents them.
Plastic shrinkage cracks occur in the first hours after pouring, when the concrete surface dries out faster than the bleed water can replenish it. The result: fine cracks that affect the durability and appearance of the floor — and that can be prevented with a minimal investment.
How micro fibres work
Synthetic micro fibres such as Promicro and Profib disperse homogeneously through the mix at a dosage of just 0.6–1.0 kg/m³. During the plastic phase, they absorb the tensile stresses that would otherwise lead to cracking. An additional benefit is a denser, higher-quality surface.
Anyone wanting to take sustainability a step further can choose basalt: Basalt Chopped and Basalt Roving are made from natural volcanic rock, chemically inert and fully recyclable.
Dosage and processing
Micro fibres are added directly to the mixer or truck mixer — Promicro even comes in dissolvable 1 kg bags. No adjustment to the mix design, no extra equipment. Not sure about the right dosage for your application? Our specialists are happy to give you personal advice.