×
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

Jobs

PCI Handbook load tables for Hollowcore Plank

PCI Handbook load tables for Hollowcore Plank

PCI Handbook load tables for Hollowcore Plank

(OP)
Can anyone tell me if the safe superimposed service loads tables in the PCI Handbook are based off of a 1 ft width of section or the 4ft width of section shown? Obviously there would be a big difference in the section properties, and in return a difference in the allowable safe superimposed load. If it is based off of the 4ft width, is there a quick and easy way to reduce the value. I can't see it as being as easy as dividing by 4.
My other question is regarding the f'c. I am checking an existing building, and I don't know the f'c of the precast used. I can assume 3000 psi, but the values in the PCI Handbook are based off of 5000 psi. I looked in the Handbook to see if there was a way to reduce the values, but I didn't see anything.

Thank you for the help.

RE: PCI Handbook load tables for Hollowcore Plank

The safe superimposed load tables in the PCI Handbook are in PSF terms so the width doesn't enter into the issue.

Most precast, over the years, has been generally 5,000 psi minimum.

RE: PCI Handbook load tables for Hollowcore Plank

Look at the Key in the upper left area. The loads are in psf.

RE: PCI Handbook load tables for Hollowcore Plank

The edition I have (2nd) gives hollowcore superimposed loads in psf, so it's basically a one foot section of hollowcore.
As far as the concrete strength, why do you want to reduce it? Do you know that it's 3000 psi? Precasters have been using high strength concrete for a long time. Plus for bending capacity, concrete strength has a small effect. I think you're safe in using the table values.

RE: PCI Handbook load tables for Hollowcore Plank

Wow - great minds think alike! And at the same time!

RE: PCI Handbook load tables for Hollowcore Plank

(OP)
The building was built in 1970, so I wasn't really sure what strength precasters were using back then. I assumed it wouldn't have been less than 3000psi. I've tried finding something on the drawings, but nothing shows up, and I don't have the existing specs or shop drawings. Thank you all very much for you help.

RE: PCI Handbook load tables for Hollowcore Plank

Precasters of flat slabs cannot afford to go much below 5000 psi because they need the higher strength to turn the plant around daily, which requires cutting the 400' to 600' long planks from the setting beds on a fast schedule.

One strength advantage they have is that they are in a planned facility with inside aggregate and cement storage plus heated beds, (if required). Having a uniform supply of aggregate and an in-house lab helps to maintain uniformity.

Dick

Engineer and international traveler interested in construction techniques, problems and proper design.

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!


Resources