What Is Curing Of Concrete | Importance | Purpose | Methods

 

Curing of Concrete is the phenomenon of maintaining the presence of moisture in freshly placed concrete to complete the hydration process for getting the required potential strength of the concrete.

Why Is Curing of Concrete Important?

Concrete is the mixture of cement, sand, aggregate, and water in specific proportions. Concrete is the most prominent material required to build any structure, and within the concrete, cement is the most significant material. Cement acts as a binding material. Without cement, the concrete won't even settle initially.

In concrete, the water-cement reaction is exothermic. When concrete is placed in the desired place, the heat produced in the concrete due to the water-cement reaction evaporates the water in the concrete and causes moisture loss. So, to avoid the lack of water in the reaction of concrete, water is sprayed on the surface of the concrete.

If water is not sprayed then there will be a lack of moisture, due to which cement-water reaction does not occur anymore, causing a lack of formation of the required strength of concrete.

So, the purpose of curing concrete is listed below:

1.   To maintain moisture in the slab so that concrete continues to gain strength.

1.   To enhance strength, durability, permeability, etc. in the concrete.

1.      Curing helps in avoiding shrinkage, cracks in the concrete.

How long does it take to completely cure the concrete?

The complete curing process might take almost a month depending upon the surrounding weather and temperature, ratios used in the concrete mix, placement, and finishing techniques.

•  After 24 to 48 hrs, the concrete settles initially and the formworks can be removed. A person can even walk on the surface of the concrete after initial settlement.

•  After 7 days, the formation of desired strength of concrete is partially completed. People can walk and ride vehicles at this stage above the concrete.

•  After 28 days, the concrete attains a strength of 90 to 95% of its true potential. The remaining 5% might take a year to complete depending upon the materials used.

Different methods of Curing the Concrete

•  Wet coverings: With the help of wet jute bags or hessian cloth placing at the top of the concrete provides continuous moisture in the concrete. Especially while curing concrete of staircase, we use this method.
  
  
  
• Waterproof paper or plastic fil seal: By covering the structure with the help of a plastic sheet, the passing of air is avoided which further prevents the evaporation process in the concrete, and moisture presence is maintained.

•  Spraying: This is one of the easiest methods of curing concrete. We simply spray the water through the pipe in the concrete placement area in this method.
  
  
  
• Ponding: Mainly in the structures like slabs, after the concrete is laid. It initially takes 24 to 48 hrs for initial settlement. After initially settled, water is maintained at the surface of the concrete of very low depth. This continuously provides moisture in the concrete.