Strengthing of existing garage flat slab with drop to handle extra firetruck load

[saadyacop]

Hi,
I have an existing slab 60 years old with drop panels and column capitals. we need to strength the slab for firetruck access way.
Please could you refer me to any literature or references?
Thanks,

 

[structSU10]

what aspects of the slab need to be strengthened? flexure, one-way shear, punching shear? How far 'overstressed' is your slab?

 

[saadyacop]

In this early stage, not sure because I don't have structural drawing, may be i need x-ray scan to locate bars.

 

[structSU10]

If you lack drawings defining the structure you will need to do quite a bit of testing / investigation to determine capacity.

GPR scans to find rebar spacing, cut holes to measure slab thickness, chip concrete to measure bar diameters, take bar samples to test tensile strength, concrete samples to test concrete strength, etc.

It is still difficult to have a lot of confidence in design parameters based on limited testing, so you would want to be conservative.

for strengthening, however, CFRP is an option for flexure. there are numerous methods to enhance punching shear capacity by use of prestressed bolts, hilti has a method in europe, and so forth.

Need to know what you have to strengthen to get in deeper though.

 

[saadyacop]

Thank you.

 

[Ingenuity]

ACI has a very good document that accompanies ACI 562-16 Code Requirements for Assessment, Repair, and Rehabilitation of Existing Concrete Structures entitled MNL-3(16) Guide to the Code for Assessment, Repair, and Rehabilitation of Existing Concrete Structures: Link

It goes through several examples/case studies and Example #4 is a Parking/Plaza Slab Strengthening project where they go through detailed strengthening concepts/options, assessment methods, investigation, design etc.

A document that gives you a good starting point.

 

[saadyacop]

Many thanks.