Curing
 Often an overlooked procedure resulting in a poor, weak finish. It is essential that once the concrete has been laid and finished it is covered ASAP. You must prevent the concrete from drying out too quickly. Equally you must not lay concrete in freezing conditions, typically below 5 degrees C. Where overnight temperatures are expected to fall below freezing you should ensure an air gap is left between the curing membrane and the concrete. As a general rule if the forecast indicates freezing conditions postpone the concrete work until conditions improve. Typically the curing process should be left in place for 7 > 10 days depending on ambient temperatures.
When can I use it?
We can only offer general advice as site, weather and concrete varies but typically,
o Foot traffic - 2 days.
o Vehicle traffic - 7 days.
Bad Weather
You must protect fresh concrete from rain. This can be achieved via a pre constructed frame or by suspending a sheet over the fresh concrete. Rain will leave the concrete surface pitted and unsightly but, more importantly, may 'over wet' the initial surface leading to the cement reaction being greatly reduced and ultimately a soft, powdery surface that will quickly wear away when used.
Slump
The actual wetness of the mix. From semi dry through to flowing, it all depends on what your actually doing e.g. trenchfill would be flowing, kerb bedding would be semi dry. Normally measured in units a semi dry would be 25 > 35, a medium slump would be 50 > 70 and a high slump would be 125. It is always the customer's responsibility to set and control slump on site. |
