As we know the main purpose of the curing is to reduce the loss of water from freshly placed concrete. Also, it reduces the rate of heat loss to the atmosphere and minimizes the temperature gradient across the concrete cross-section.
What are the methods we are using for curing
- Ponding and Immersion
- Wet Coverings
- Fogging and Sprinkling
- Plastic Sheets
- Membrane-Forming Curing Compounds
Let discuss the disadvantages of curing methods ponding and using polythene sheets.
This method only can be used for flat surfaces, such as pavements and floors.
Ponding requires considerable labour and supervision, So this method is to be applied only for small jobs.
Also, it is readily affected by weather condition (cold wind). Moreover, a large amount of water used has to be disposed of the construction sites after curing.
This method of curing is based on the principle that there is no flow of air over the concrete surface and thereby no evaporation can take place on top of the freshly concreted surface by the provision of polythene sheets.
However, it suffers from the demerit that polythene sheets can be easily blown off in windy condition and the performance of curing would be affected.
Curing with polyethene sheets can cause patchy discolouration, especially if the concrete contains calcium chloride and has been finished by hard steel troweling