What is Development Length and why it's provide

DEVELOPMENT LENGTH

• Development length is a extra length of steel bar which provide for anchorage the steel and concrete (or any other two type of material)
• Main reason behind provision of development length is "stress on reinforcement is  transfer to the concrete".  in sort it's create bonding between steel and concrete. 
• Transfer the bar Load without slip to prevent the bar from pulling out under tension.  

Understanding Development Length in Reinforced Concrete

In reinforced concrete design, development length refers to the length of embedded reinforcement required to develop the full strength of the reinforcement at a critical section. In other words, it is the minimum length of reinforcement that must be embedded in the concrete to ensure that the reinforcement can transfer its full design stress to the surrounding concrete without slipping.

Development length is an important consideration in reinforced concrete design because it ensures that the reinforcement can develop its full strength and effectively transfer loads to the surrounding concrete. If the development length is not sufficient, the reinforcement may slip and fail to transfer its full design stress to the concrete, leading to failure of the reinforced concrete member.

The development length required for a given reinforcement depends on several factors, including the diameter of the reinforcement, the strength of the concrete, and the type of reinforcement (e.g., deformed or plain). The development length can be calculated using formulas provided in design codes and standards.

In practice, development length is provided by extending the reinforcement beyond the critical section by a distance equal to or greater than the calculated development length. For example, in a reinforced concrete beam, the reinforcement may be extended beyond the support by a distance equal to or greater than the calculated development length to ensure that the reinforcement can develop its full strength at the support.

In conclusion, development length is an important consideration in reinforced concrete design that ensures that reinforcement can effectively transfer its full design stress to the surrounding concrete. By providing sufficient development length, designers can ensure that reinforced concrete members can safely carry their design loads.