We have noticed some distress in the concrete columns in our apartment, and we have chosen to strengthen it using steel. We are using C section SAIL steel to be fixed on the two sides of the column till it fits flush with the beam. At the ground level, it is anchored to a 12 mm thick plate to the pedestal of the foundation. The complete beam is then plastered
I have two questions-
- Does the above method of strengthening work in reality?
- How should the connection to the beam and the column be made? Will the steel C section on either side of the column with the beam is enough?
AdityaBhandakkar
Hi, generally, the lifespan of the RCC structure is 100 years.IS 456:2000 suggest all the repairs of RCC structures due to various causes of failure.poor workmanship and the excessive amount of water to cement ratio is the main cause of deterioration of RCC members. Per 50 kg bag of cement requires 15 to 18 liters of water. If an excess amount is used, it causes deterioration of structures. Also, inadequate concrete cover reinforcement is exposed to an environment that causes rusting and failure after some time.
To alleviate the distressed in the column, identification of the location off distress is a preliminary inspection.
Then perform a detailed investigation. In this part of the checking of the strength of concrete, chemical analysis of concrete and corrosion test will be carried out.
Following are the methods of repair of cracks:
aviratdhodare
There could be broadly two types of corrective treatment:
a. Support the concrete column with adjoining steel column ( an ISMB section will be better.), for ordinary house 12 feet height column, suggested steel ISMB is 250X 150 mm section.
b. if column is found reparable, it is renovated with ‘ Jacketing ‘ around it. That is, scarp old peeling plaster, reach to reinforcing material, apply corrosive preventive liquids available from a good hardware store. Then, tie new reinforcement over the old reinforcement. Over it place 4-inch fresh cement concrete with aggregate of 12mm. Of course, steal or wooden scaffolding will be required.
It will increase the size of the column but will give strength to it.
BUT Note: if the column has already buckled down.. it is advisable to immediately get the help of an engineer and show him the site because if the column collapses, building or roof over it is in danger.