Concrete Covers design depth of steel from the exposed surface of the concrete. Concrete Cover is provided for the reinforcement in Reinforced Cement Concrete. It is provided to protect the steel bars from corrosion depends upon the quality of concrete. The cover is defined as the distance between the outer surface of the concrete to the inserted reinforcement.
The requirement of concrete cover.
Concrete Cover Basics differ from various Columns, footings, slab. It is provided to protect the steel bars from corrosion depends upon the quality of concrete. The Minimum cover various in different positions, its depends upon the exposer condition of the concrete.
- Nominal cover in the COLUMN should not less than 40mm
- Nominal cover in the SLAB should not less than 15mm
- Nominal cover in the FOOTING should not less than 50mm
- Cover in the BEAM is should not less than the 25mm
Concrete Covering is provided For every element of the building especially it affects in Slabs, Beams, footings where the reinforcement is used. Covering varies according to the dimensions of the elements. In order to maintain the proper arrangement of reinforcement and to provide a covering for reinforcement. covering blocks are used.
Difference between Clear cover, Nominal cover, and Effective cover. The clear cover is the distance between the outer surface of the concrete to the surface of the reinforced bar. The nominal cover stated distance from face of the member to the outermost face of the reinforcement including stirrups. Nominal covers is same like the clear cover. The effective cover is the distance from measured from the face of the member to the center of the area of the main reinforcement.
Effective Cover = Overall depth – Effective Depth
Concrete Cover in Columns
The Basic principle column cover depends upon the width of the column, it satisfies the second condition. The covering for reinforcement in the column is 0.050m from all sides and same reinforcement is designed accordingly. The Dimensions of Reinforcement in the column are 0.40m and 0.35m. The minimum clear cover between reinforcing bars shall be in match with IS:456 – 2000 code of practice. According to relevant code, the concrete cover must have a minimum size of 25 mm, or less than twofold of the diameter of the bar should be provided. It should be placed at the end of the reinforcing bar.
Concrete Cover for Slabs
The length and width of the slab are 1.3m and 1.0m. The covering of 0.1m is provided if the length of the bar is more than 0.6m. The covering of 0.1m is provided from all the sides of the slab. The reinforcement bar’s diameter does not exceed 12 mm, where the concrete cover of 25 mm is applicable for reinforcement.