Question

A good method of maintaining a satisfactory state of wetness in a body of concrete to promote continuous hydration when original water/cement ratio used is NOT less than 0.5 is known as:
1. membrane curing
2. water curing
3. application of heat
4. high-pressure steam curing

Answer 1

Correct Answer - Option 1 : membrane curing

The different type of curing methods and their brief explanation is given below in tabulated form :

Method of Curing	Brief Characteristics
Shading Of Concrete Work	This is adopted mainly in case of large concrete surfaces such as CC Roads. This is done by using canvas stretched on frames.
Covering Concrete Surfaces with Hessian or Gunny Bags	This is a widely used for structural concrete in building construction. The exposed surface of concrete is prevented from drying out by covering it with hessian, canvas or empty cement bags.
Sprinkling of Water	It is mostly used for curing floor slabs. Water is sprayed by use of perforated plastic boxes.
Pounding Method	It is suitable for curing horizontal surfaces such as floors, roof slabs, and road and air field pavements.  After placing the concrete, its exposed surface is first covered with moist hessian cloth. After 24 hours, these covers are removed and 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.
Membrane Curing	The wetted concrete surface is covered by a layer of water proof material, which is kept in contact with the concrete surface of seven days. This membrane prevents the evaporation of water from the concrete (provides continuous hydration).  The membrane can be either in solid or liquid form.  Bituminized water proof papers, wax emulsions, bitumen emulsions and plastic films are the common types of membrane used.