×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

cantilevering a steel deck with concrete

cantilevering a steel deck with concrete

cantilevering a steel deck with concrete

(OP)
I want to cantilever a 2" corrugated 16 gauge steel deck  with a total of 4" light load concrete 5' past an on grade footing. The deck will be mechanically connected with 3/4" anchor bolts every 2'. The total length of each sheet of corrugated 16 gauge steel is 25' there are three (3) on grade footing with the middle footing having number 4 rebar sticking up 3' to be bent down onto the corrugated steel. My question is what size mesh should I use and should I tie number 4 rebar to the number 4 sticking up and tie the mesh (size?) to everything and then pour the concrete. Will this be strong enough without supporting the cantilever section.? The footing specs 8" above earth 12" wide 30" deep soil rock/clay concrete 6bag 3/8 gravel number 4 every 12" with 4 number 4 running horizontally.

RE: cantilevering a steel deck with concrete

What kind of load you are going to have on this deck? Is this a balcony? Or you have a wall supporting roof at the edge of deck? Or you going to park a truck on this deck?

RE: cantilevering a steel deck with concrete

(OP)
Sorry - the load is a residential patio-not a car park, there will be no additional structures built upon the patio. The patio is on grade with the 5' cantilever extending over a hill.

RE: cantilevering a steel deck with concrete

From ASCE7-98, Live Load for balconies equal to 100 psf.
From Vulcraft catalog, Weight of slab equal to 35 psf.
Total Moment for 5 ft cantilever equal to M=(ql^2)/2=135*25/2=1690lbs*ft=1.69k*ft
Bending stress in deck equal to fb=M/S=(1.69*12)/0.653=31ksi
For deck with Fy=33ksi, allowable bending stress Fb=0.6*33=19.8ksi<fb=31kso  - NOT GOOD.
Working backwards you will find that maximum cantilever shall be not longer than 3.5 ft.

Good luck.

RE: cantilevering a steel deck with concrete

(OP)
whymrg Would this calculation included additional steel reinforcement? Or is it due to the light load concrete's weight?I am assuming if the additional steel mesh plus rebar will not help and I still want to cantilever the deck/patio to 5' then I will have to run a stringer under the steel deck. thanks

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login


Resources

White Paper - The New World of Thermoplastic Manufacturing
Digital-direct thermoplastic manufacturing offers exceptional quality, opens the door to novel design parameters not possible with injection molding while also bypassing the long lead time and up-front investment in injection molding tooling, offering a better total value proposition. Download Now
White Paper - Strategies to Secure Connected Cars with Firewalls
White-hat hackers have demonstrated gaining remote access to dashboard functions and transmissions of connected vehicles. That makes a firewall a vital component of a multilayered approach to vehicle security as well as overall vehicle safety and reliability. Learn strategies to secure with firewalls. Download Now
White Paper - Model Based Engineering for Wire Harness Manufacturing
As complexity rises, current harness manufacturing methods are struggling to keep pace due to manual data exchanges and the inability to capture tribal knowledge. A model-based wire harness manufacturing engineering flow automates data exchange and captures tribal knowledge through design rules to help harness manufacturers improve harness quality and boost efficiency. Download Now
White Paper - What is Generative Design and Why Do You Need It?
Engineers are being asked to produce more sophisticated designs under a perfect storm of complexity, cost, and change management pressures. Generative design empowers automotive design teams to navigate this storm by employing automation, data re-use and synchronization, and framing design in the context of a full vehicle platform. Download Now

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close