Curtailment of Beam Reinforcements

Curtailment of beam reinforcements is discussed in this article. Different detailing techniques applied as per the various guidelines are explained in detail for better understanding. Most of the detailings are based on the British Standards.

Method of Curtailment of Beam Reinforcements

The following figure extracted from the Standard Method of Detailing Structures indicates the curtailment of beam top reinforcements.

The simplest method of doing the curtailment of reinforcement is indicated in the above figure. In this method, we need to provide the tension anchorages length form the no longer required point. No longer required point is defined as the location where there is no requirement of having that bar. It is the point that has the bending moment capacity of continuing bars. Beyond this point, we continue an anchorage length from discontinuing reinforcement. Similarly, bottom reinforcement also can be curtailed as shown in the following figure.

In addition, when there are not continuing bars, the same theory will be applied. However, another requirement for the lapping of reinforcements shall also be satisfied. For Example, Refer to the following figure.

Curtailments of this nature can also be observed in reinforcement detailing. In this situation, main hogging reinforcement bars are terminated and then smaller bars continue towards the mid-span.

For example, when we required 2T25 bars hogging, they can be terminated and a smaller bar like 2T16 can be continued into the span. Based on the lapping arrangement of the reinforcements, lap length may need to be multiplied by 1.4 factor. Cl 3.12.8.13 of BS 8110-1:1997 could be referred to as a multiplying factor.