How can we errect the coloumn

archdevil

Royal Member
How can we errect a column here???

this is first floor slab and i need to extend to the second floor. pls suggest better options...!!

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Its depends, if the level of TOC higher than top of slab concrete , then we have to crush the concrete surround rebar and clean rebar in proper way to establish overlaping for next floor column reinforcement, this should consider the availble exposed rebar lenght to do extension by mechanical overlapping or field welding if applicable , for more safe action we have to drill into old concrete and using chemical bond .
Secound senirio the TOC is same of slab concrete slab level , in this case drilling into old concrete and using welding between old and new rebar with chemical bond is required , considering the new rebar for next column shall be as extension to provide minmum distance for overlapping .
 
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Two options
1 obviously destructive method, by breaking the old column and adding lapping to old bars.

2nd by using hilti fastners (mechanical or Chemical) you can add the rebar for new column

Obviously considered that you had consulted to structural engineer for Load carrying capacity of existing structure
 
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amd007

Elite Member
Check with the structural consultant first before starting with any extension work like this one.

The traditional method would be to break the columns up to beam bottom, break the beams up to L/3 of beam length and slab all around the column up to L/3 in a square shape.

Before starting with the breaking you will need to support the structure thoroughly using metal props at spacing similar to shuttering design till foundation level and you will need to maintain these supports till the 28 days strength is achieved by the 2nd-floor slab after it is cast. If you have done masonry work at bottom floors then supporting at openings is advisable.

The joints in the beam and slab should be a preferably angular and proper epoxy bond coat of concrete grade strength shall be applied at the time of concreting.

Cast the concrete in slab, beams, and slab by doing the necessary formwork, after the repaired slab has gained 28 days strength only then you can start the construction of the above 2nd floor.

In addition to the above methodology you can also strengthen the intersection of the new concrete with old by means of low viscosity pressurized grouting at 150c/c spacing, and also if budget allows then FIBREWRAPPING OF THE INTERSECTIONS AT BEAMS, SLAB AND COLUMNS CAN BE UNDERTAKEN.

I would not advise HILTI METHODOLOGY DUE TO SEISMIC REASONS.