Problem: How to stop new concrete cracking?
Whether you are pouring a small slab of concrete to form a garage base or laying out a new industrial warehouse floor, two points need to be borne in mind when it comes to curing new concrete. Firstly new concrete may appear to have cured “solid” in as little as 24 hours but in reality a 6 inch floor slab takes 6 months to fully cure through. Secondly, as water evaporates out of concrete its volume inevitably shrinks slightly. Hydration or shrinkage cracks occur when the top part of a new “pour” dries out more quickly than the bottom, creating a stress point between the layers.
Solution: How to stop new concrete cracking?
1. Apply a chemical curing membrane
Avoid turning up the heating and if outdoors, protect the surface from direct sunlight. As soon as the initial cure has hardened the surface, apply a coat of our clear "K-Seal Total Cure" which slows down the rate of evaporation, promoting even hydration.
2. Reduce the volume of water in the mix
It sounds obvious but the less water you use in your concrete mix, the less there is to evaporate off during the hydration process. If you can, sacrifice a little of the concrete's mobility by using a stiffer mix with less water.
3. Cover the concrete
Retaining moisture in the surface is especially important in extreme weather e.g. high temperatures or strong winds. Cover the surface with polythene or dampened hessian (sack) cloth to maintain even hydration.