Plastic Shrinkage Cracking in Concrete Materials
Cause: Plastic Shrinkage Cracking occurs as a result of very rapid evaporation of the concrete while it is still in a plastic state. Hot, dry, and windy environmental conditions and lack of countermeasures employed.
- Timing the pour during cooler temperatures (evening or early morning)
- Providing temporary shelter from the sun and wind
- Use of a monomolecular evaporation retarding film
Possible repair solutions:
- Structural Concrete: Gravity feed a low-viscosity epoxy resin into this type of crack to fill and structurally re-bond. Concrete of greater thickness may require low pressure injection methods.
- Functional/Aesthetic Concrete: Grind, rout or saw the crack out to provide a recess into which a semi-rigid epoxy, polyurea, or polyurethane joint filler/sealant can be placed. Material selection will depend on specifics.