Monolithic construction of beam and slabs

by Qamar ali
(loralai pakistan)

Question:

For construction of beams and slab which method will be successful monolithic or non monolithic.

Answer:
Hi Qamar, thanks for visiting

Both method will work fine as long as the construction joints are wisely chosen. For small pours it will be ideal to pour the beams and slabs monolithically to achieve a consistent look in the entire structure.

For suspended slabs, avoid putting construction joints at mid span because structurally that's high stress area. It is best to put construction joints at center line of column which in most cases will have beams.

Concrete beams for structural reasons are not allowed to be poured in section i.e. do not pour half of a concrete beam whether in the long direction or short.

The exception is if the top section if the concrete beam is to be poured with the slab but the reinforcements and slab dowls to connect slabs to the beams are left exposed.

In bigger projects or in the case of limited shoring material there is no choice but to pour in sections or pour the beams first. This can be true for concrete beams and slabs cast on the ground or cast on shoring as in the case of suspended slabs.

If you want separate pours or the circumstance don't allow monolithic pour, it is best to pour the beams first. Beams are tied in to columns or walls which are perfect for construction joints that can work as control joints as well.

If poured non-monolithic, make sure to vibrate the concrete really well at the connections between new and old concrete to allow both to bond. Vibrating of the concrete will also help make for a smooth transition from new to old concrete aesthetically.

Vibrating concrete will minimize honeycombs which occur for the most part if the concrete is poorly vibrated particularly for suspended slabs or concrete exposed to view.

Hope this helps
Good luck