Tek-Tips is the largest IT community on the Internet today!

Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!

  • Congratulations cowski on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Why test the 28 day grout when 7day passed?

Status
Not open for further replies.

njcadz

Civil/Environmental
Joined
Aug 15, 2007
Messages
4
Location
US
Client ordered 3000 psi Grout. Project requires 2000 psi. Contractor wants to know if we still have to break the 28 day break eventhough at 7 days exceeds the 2000 psi spec.

What are the unseen potentials with not breaking the 28 day grout samples?
 
unless the testing company is offering a rebate, break'em.

28-days are considered the legitimate break and the 7-day is considered a diagnostic. Concrete breaks above the specified strength on the 7-day break almost a third of the time in my experience (and usually more so for grout), but the 28-day still gets broken and reported. Besides, if you buy 3000 you should get 3000.

i have heard tales of unstable concrete that gains strength and loses it because of a bad secondary reaction, but whether that can happen b/n 7 and 28-days i don't know.
 
Status
Not open for further replies.

Part and Inventory Search

Sponsor

Back
Top