Post-Treatment Guidelines

Post-Treatment Guidelines

Post-Treatment in Warm Weather

When the air temperature reaches or exceeds 28°C, the following steps should be taken: The post-treatment of compacted fresh concrete should begin immediately after placement to prevent rapid drying, which can lead to cracks.

• The surface should be sprayed with a curing agent (evaporation retarder): this creates a barrier layer on the concrete surface. Using a paint sprayer is ideal for this spraying. Apply just enough post-treatment to the still-damp surface so that the product does not run off - or, if the surface is horizontal, just enough so that it does not pool.
• Water Curing: Spray water onto the surface frequently enough to prevent drying out. Interrupting this treatment could cause the concrete to heat up and to crack during the next treatment. Side walls can be protected from rapid drying by leaving the forms in place longer than usual (3 days instead of 1-2 days).

Post-Treatment in Cold Weather

• In cold weather, it is advisable to reduce the water/cement ratio of the concrete, to add a plasticizing admixture instead of water, and to work with warm concrete if possible.
• To prevent damage to the new concrete, it must be kept at least +5°C, so it is recommended to cover the placed concrete with straw bales or other insulating materials such as styrofoam. The formwork should also be kept warm with straw bales or similar materials. Drying can also be prevented by covering with plastic sheeting. It is best to create an air layer (air cushion) between the concrete and the foil, because still air is effective insulation.
• For temperatures of -10°C or lower, thin sections require more than cover. In such cases, freshly poured sections should be surrounded by protective walls and kept at at least +5°C with the help of heating devices.
• Concrete should not be exposed to frost until it has reached a compressive strength of ≥ 5 N/mm² (frost resistance).
• Fresh concrete should never come into contact with frozen soil or frozen concrete!