Concrete Curing Methods

1. Ponding:-

This method adopted for floor slabs, roads, air field pavement and horizontal concrete surfaces. The concrete surface divided into small ponds, and these ponds are filled with water continuously for 14 days. Generally After 24 hours, of concreting small ponds of clay or sand are built across and along the pavements. The area is thus divided into a number of rectangles. The water is filled between the ponds. The filling of water in these ponds is done twice or thrice a day, depending upon the atmospheric conditions. Though this method is very efficient, the water requirement is very heavy. Ponds easily break and water flows out. After curing it is difficult to clean the clay.

2. Wet coverings:-

This type of method performed for columns, footings, and the bottom surface of slabs, where ponding is not possible. Impermeable coverings like gunny bags or hessian are required to cover the concrete; these membranes sprayed with water to keep the concrete moist.

3. Membrane Curing of Concrete:-

Ponding is not suitable at the places where the atmospheric temperatures are high. Water gets evaporated due to the excessive heat. Membrane curing is adopted to prevent the loss of water content due to atmospheric temperature from concrete. 

Membrane curing helps seal off by forming an impermeable layer on the concrete surface, which eventually resists evaporation. This procedure is generally performed by brushing or spraying the curing compound on the concrete surface.

Synthetic resin curing compound:-

Synthetic resin is a compound that forms as an impermeable membrane on a concrete surface to resist the water evaporation from concrete. 

To proceed with further plastering, the synthetic resin membrane can be easily removed by spraying the hot water on the concrete surface. Hence it is suitable at areas where subsequent treatment applied to the concrete.

Acrylic curing compound:-

Acrylic Curing compound is a polymer-based curing compound obtained from the polymers of Acrylic acid. 

The best part of Acrylic based curing compound is there is no need to remove this compound for plastering. Acrylic helps to achieve excellent adhesion to plastering. 

Wax Curing compound:-

Wax curing has similar properties of synthetic resin. The usage of wax on the surfaces to be painted or tiled is not recommended because wax hampers the adhesion between surface and plastering or tiling. 

Chlorinated rubber curing compound:-

Chlorinated rubber forms a thick membrane on the concrete surface when laid. Using of chlorinated rubber-based curing compound seals the concrete effectively with no minute pores left. But the age of chlorinated rubber is very less, and it cannot stay for longer times. 

4. Steam curing of concrete:-

This procedure is adopted at a Precast concrete plant where the concrete members are mass-produced. Steam has heat moisture in it, and it is sprayed on the concrete surface to keep concrete moisture and also increases the concrete temperature, which eventually quickens the pace of hardening concrete.

In steam curing the temperature of steam should be restricted to a maximum of 750C as in the absence of proper humidity (about 90%) the concrete may dry too soon. In case of hot water curing, temperature may be raised to any limit, ay 1000C.

5. Curing of Concrete by infrared radiation:-

This method is adopted in cold climatic regions. In this procedure, the infrared radiation is applied to the concrete, increasing the initial temperature, which increases the strength of concrete. This is the most effective method than steam curing, as raising the initial temperature in concrete does not decrease the ultimate strength of concrete. This technique is adopted for the hollow concrete members where the heaters are placed in concrete members which emit the temperature of 90'.

6. Curing of concrete by an Electric Current:-

In this method, the concrete is cured by passing an alternating current to it. Two plates, one at top and another at the bottom of the concrete surface, acts as an electrode, and then the alternating current is passed to them. 30V or 60V of potential difference maintained among these electrodes. The curing attained by concrete at 28 days can be achieved within three days by performing this method.