Clear Cover and Nominal Cover used for RCC Structure

The concept of Clear cover and nominal cover is seen in the Reinforced concrete structures.

Reinforced concrete structures have been main structural materials for over a century and still the most popular material for public structures all over the world. The concrete structure is durable enough to keep its shape for a long time.

The reinforced concrete structure refers to the members like beams, boards, columns, and roof trusses etc. which are consisted of concrete and steel bars.

In these structures, the steel bars are covered by concrete but their mechanical properties will still lose due to the fire to destroy the whole structure.

In this design of reinforced concrete structures, the provided reinforced is inserted in the concrete upto a particular distance from the face of the member as there are some reasons.

The reasons are discussed below:

• It will provide protection to reinforcement from erosion
• It will also provide fire resilience to reinforcement.
​• It will also supply sufficient embedded depth so that reinforcement grows the requisite stress.

This distance is measured in various ways and known by different names like:

• Clear cover: This is the difference from the face of the member to the outermost face of the reinforcement including shear or torsion Stirrups or links.
• Nominal cover: This cover is like the same as Clear Cover although it has different name; actually the name is a term that is used by the code. It is the distance measured from the face of the member to the outermost face of the reinforcement including Stirrups or links.

To get information on other clear cover and nominal cover, go through this useful civil engineering video tutorial.

Video Source: CE&T-Civil Engg & Technology

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Published By
Rajib Dey
www.constructioncost.co
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Illustration of stress-strain curve for concrete and steel

This construction video tutorial will teach you the detailed process for creating the design of stress-strain curve of concrete and steel by adhering to the IS 456:2000. Limit State Method is used here for these curves.

As the tensile strength of concrete as compared to compressive strength is very week, it can only withstand compressive stress. Alternatively, the tensile strength of steel is very strong and it can withstand both tensile and compressive strength.

While going to design a structure located in costal area and as per IS code the minimum grade of concrete for this structure should be M30 and concrete can’t be used below this grade. It is known that 30th characteristic strength of concrete cube of size 150 mm at 28 days. The characteristic strength is represented with the symbol as fck.

The stress-strain curve for hardened cement paste is nearly linear. The aggregate is more stiff as compared to the cement paste and will consequently deform less (i.e. contain a lower strain) under the similar applied stress.

The stress strain curve of concrete remains among those of the aggregate and the cement paste. But this alliance is non-linear over the most of the range. This non-linear behavior occurs because of formation of micro-cracks for the following reasons :-

(i) At the interface among aggregate particles and cement paste due to the differential movement among the two phases, and
(ii) Inside the cement paste itself.

These cracks are developed owing to variations in temperature and moisture and the application of load.

To learn the detailed process, watch the following video tutorial.

Read Continue

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Published By
Rajib Dey
www.constructioncost.co

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