Basic Rules For Lapping in Column Reinforcement
The lapping zone in the column indicates the length of overlap between two reinforcing bars, which has been used in the construction of the concrete columns. The lapping zone in the concrete column helps to ensure the continuity of the reinforcement, as well as providing sufficient strength to the columns. In addition, the lapping length i the concrete columns also helps to ensure that the loads have been transferred and distributed effectively.
The lapping has been done at the points of the concrete columns, where the bending moments are low. For example, the lapping has been done at the mid-height of the concrete column. In addition, the laps are staggered at the different sessions of the concrete column, which helps to ensure the uniform distribution of the reinforcement in the concrete column.
Learn about the accurate lapping length of the steel bars in the reinforced columns
The lapping length of the steel bar is one of the important factors in reinforced columns, as it helps to estimate the strength of the connection between two steel bars. In the case that the lapping length of the steel bars is too short, the ability of the steel bars to transfer the load may be hampered, which can increase the risks of potential failures. In general, two types of lapping lengths have been used in the reinforced columns, which are:
- Tension lap: This type of lapping length has occurred in those areas where the steel bars have been subjected to tension. For example, the tension lap has been used in the upper portion of the columns.
- Compression lap: The compression lap has occurred in those areas which are subjected to compressive forces. For example, it has been used in the lower portion of the columns.
Discuss the effectiveness of the lapping zone in the reinforced columns
Structural strength maintenance
The lapping zone in the reinforced columns helps to ensure the effectiveness of the steel bars. This steel bar's effectiveness influences the resistance capacity towards the bending and shear forces, thus increasing the overall strength of the concrete columns.
Crack and failure prevention failure
The appropriate lapping zone of the concrete columns also helps to reduce the risks of cracks or any kind of structural failure under load.
Meeting safety standards
Appropriate lapping in the concrete columns also helps to ensure that it complies with the regulations and safety standards of the building structure, which is important for maintaining the safety of any kind of construction project.
Factors influencing the effectiveness of the lapping
The structural integrity of the concrete columns has been significantly influenced by the lapping zone of those columns. In this context, several factors are responsible for maintaining the structural integrity of the concrete columns, which are as follows:
Lapping staggered at different heights
The lapping should be staggered at the different heights of the steel bars in the concrete columns. In this context, the creation of the weak points along with the single plane can be avoided. The continuity of the reinforcement throughout the concrete column has also been ensured by the staggered lapping, which helps to reduce the risks of failure of the concrete column at a specific location.
Lapping done in critical zones
In the case of the highly stressed regions of the concrete columns, the lapping should be avoided. For example, the lapping should be avoided near the base of the column or the beam-column junction. In the case of the lapping in the critical zone being unavoidable, the alp zone should be strengthened through extra reinforcement.
Adequate concrete cover
There should be adequate concrete cover for the steel bars in the reinforced concrete columns, which helps to protect them from corrosion. This adequate concrete cover also helps to ensure the proper bonding among the steel bars and the concrete. In this context, the concrete cover should comply with the design codes and standards to reduce the risks of cracking or corrosion in the concrete columns.
Maintaining adequate spacing among steel bars
There should also be adequate space among the lapping bars, which helps to ensure the effective transfer of the loads among those steel bars in the concrete columns. In the case of the lapping bars being too close to each other, the concrete around those bars may not be effectively bonded, which can significantly reduce the strength of the lap connections.
The diameter of the steel bar
A longer lapping length is required for the thicker rebars.
Concrete grade
The lapping length in the concrete columns has also been influenced by the strength of the concrete that has been used in the column.
To get more details, watch the following video tutorial.
Video Source: Civil Engineering
Design specifications
The requirements of the lapping have been dictated by those design specifications of the concrete columns, which have been provided by the structural engineers.
