×
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

Tensile Strength of concrete

Tensile Strength of concrete

Tensile Strength of concrete

(OP)
can anybody tell me a reference where I can get the tensile strength of concrete after 3 days of curing. thanks.

RE: Tensile Strength of concrete

The tensile strength of concrete is never very high, even when fully cured, so at 3 days, don't count on anything.

Also, tensile strength is more variable than compressive strength.  While there is a relationship between the two, in my experience I've seen the tensile strength be more variable.

I'm curious as to why this is important at 3 days.  Are you concerned about direct tension or modulus of rupture for flexure?

You can also do a splitting tensile test on cylinders molded for compressive strength.

RE: Tensile Strength of concrete

(OP)
It is a variable requirement in the australian code AS3735 to get the minimum reinforcement for unrestrained concrete.

min steel ratio = fct3 / fy

fct3 = the principal tensile strength of concrete at three days.

anybody have an idea where to get this value? i cant find it here in the code...

RE: Tensile Strength of concrete

Assuming the tensile strength at f'c is 10% of f'c, then the tensile strength at 3 days would be about 0.4 to 0.5 times that value, assuming approximately 22C ambient and a normal mix (w/c about 0.50 or less) without flyash or GGBFS.  So...

For 30 MPa mix, ultimate tensile would be about 3 MPa and at 3 days, about 1.5 MPa.

These are rough correlations that can be found in most of the literature (for example, A.M. Neville...any edition)

hokie66, RE, BigH....check me on this!   

RE: Tensile Strength of concrete

About 3

RE: Tensile Strength of concrete

both tensile and compressive strength is highly dependant on the mix design and curing conditions. for example if using high early strength mix design, it will be higher than if using a mix high in fly ash. Curing temperature will also play a significant role in strength gain. the best source for this is test results from the actual mix. ask your ready mix supplier for it.

RE: Tensile Strength of concrete

The tensile splitting test can high variations because of the nature of the test and variables.

In my experience the variations are higher than those for cylinders or pavers that are tested on at a controlled loading rate.

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