×
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

Lightweight concrete slump

Lightweight concrete slump

Lightweight concrete slump

(OP)
I am reviewing a mix design for lightweight concrete to be used over metal deck and also as a polished slab. We specified a 3000 psi mix with a max w/c = 0.45 and a slump of 4". The proposed mix design has a w/c = 0.42, but the slump is listed as 8" +/- 2". Is this slump common for lightweight concrete mixes? The 28-day concrete strength from the mix histories look good (5500 psi to 7000 psi).

Thanks!

RE: Lightweight concrete slump

Where I practice (Middle prairies of Canada) we have stopped specifying slump altogether and allow the contractor to specify the required slump for placement. This allows the mix designer to add water reducing admixtures to get where the contractor would like.

We will on some occasions specify slump, however it is rare. If you are specifying everything to do with the mix design, why bother even having a mix design submitted.

We specify required strength, required air, required concrete type (GU or HS etc), the exposure class and the curing type. The mix designer is required to submit a mix that meets the specifications outlined.

RE: Lightweight concrete slump

Your 4" slump is without an admixture I would assume. The only way to get 8" slump with a 0.42 w/c ratio is with an admixture.

8" sounds a little high but I had a 4000psi mix for a metal deck that had 6" slump.

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

eBook – How to Choose the Correct Corrosion Testing Method
When designing a metal component, engineers have to consider how susceptible certain alloys are to corrosion in the final product’s operating environment. In a recent study by NACE (National Association of Corrosion Engineers), it was estimated that the direct and indirect costs of corrosion in the United States is approximately 6.2% of the GDP. In 2016, that cost exceeded $1 trillion dollars for the first time. 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