Construction Process of Beam

This exclusive civil engineering article is written about the recommended practices for beam construction the types of beams with practical example.

The superstructure can be constructed in several ways. With the accessibility of average to standard quality bricks, the walls of two or three storied houses should be constructed by the bricks with the slabs, lintels, chajja etc. in reinforced concrete. The complete support to such construction is provided by the load bearing brick walls to transmit the building load to underneath soil.

But this type of load bearing wall can't resist the horizontal drifts caused by the natural hazards like earthquake or high speed storms which affect different parts of country more frequently.

For this purpose, the load bearing wall construction should be retrofitted. Besides, the load bearing wall is appropriate upto G+2 storied building in general.

Recently, the high storied construction coupled with natural hazards is gaining popularity and it is recommended to select RCC (Reinforced Cement Concrete) framed construction.

Fundamentally, RCC framed construction contains a series of columns arranged properly in the house which are interrelated with beams to build a frame.

The beams bear the load from slab/building and transmit to columns, and accordingly the building load is transmitted to the soil below through RCC footings. Beams extent among one or more supports, and are reinforced with primary longitudinal bars to withstand bending moment; and transverse steel (closed ties) to defy shear force.

Also Read: Design of RCC beam – Some useful tips

The purpose of beams to support the load of brick walls also (usually, the slab couldn’t bear the brick wall load), hence width of beams shouldn’t remain lower than the width of walls. Normally, beams contain minimum width of 230 to 250 mm.

The followings are the typical loads for beam design:

(i) Dead Load: Any permanent load operating on the beam, as for example self-weight of beam, dead load/super-imposed dead load of slab/staircase, weight of brick wall.

(ii) Live Load: Any non-permanent or moving load on slab.

(iii) Earthquake Load: It is based on the seismic zone where building is situated, also upon dead weight (seismic weight) of building, soil site type.

(iv) Wind Load: It is based on the wind speed, height & location of building. Also terrain and adjoining structures can help to find out this type of load.

Recommended construction practices for beams:

1. Secondary beam rebar should be provided over primary beam rebar, since the load enforcing on secondary beam is transmitted to primary beam and thus to columns.

2. The ends of the ties should be bent as 135 degree hooks. The length of bend should be minimum 10 times diameter of steel bar or75 mm. In India, such configuration must be maintained for earthquake zones III, IV and V as recommended by BIS 13920(a).