The Concrete is specially in Slabs Shrinks during the initially few hours resulting in the formation of cracks. These cracks are known as Plastic Shrinkage Cracks. These Cracks are develops due to the Drying up of the Concrete Surfaces before it hardens.

This video shows some of the measures those can be adopted at site to be prevented plastic shrinkage cracks. The Fresh Concrete should be protected directly from the sun-ray and strong winds for at least 24 Hours. Where feasible carry out the concreting works during the early hours of the day or later in the evening. Concrete should not be placed on the Dry surface.

Damping the surface of the Firm work by sprinkling the water before the concrete is placed. Avoid use of warm water and warm aggregates in order to keep the temperature of fresh concrete low.

Water shills on the concrete surface shall be maintained by sprinkling the water or cover the freshly placed concrete with tarpaulin or plastic sheet till concrete hardens. The curing shall be started as soon as the concrete starts hardening.

Summary of Prevention of Plastic Shrinkage Cracks:

Plastic Shrinkage cracks occurs due to rapid evaporation of water sheen from the surface of the freshly placed concrete

Ensure surface moisture continuously

In hot weather condition, it is preferable to do concreting during morning and evening.

Keep the concrete temperature low either by adding cold water or by avoiding the use of warm aggregates

Cover the freshly laid concrete with plastic sheets or keep the surface moist by sprinkling water.