Grout 28day break vs 7day met spec
Grout 28day break vs 7day met spec
(OP)
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?
What are the unseen potentials with not breaking the 28 day grout samples?





RE: Grout 28day break vs 7day met spec
1. The structural engineer should know the sample breaks at 28 days as a measure of the material in the project at the specified times. If this is grout for masonry, there are situations where high grout strengths are not desired and may be misleading/detrimental since the structural may often act differently. - As an example, if a grouted prism was made, you could get a false indication of the masonry strength of the outer fibers.
2. The supplier may appreciate the information for future reference regarding 7 v. 28 days strengths - if he is entitled to the reports. He should know the 7 day v. 28 day breal relationships of his materials.
3. The 28 day breaks could be very helpful in the case of a later problem and the question of accuracy and sampling comes up. You have a complete file where bad sampling, sample preparation, mishandling of samples or equipment problems could be pointed out.
4. You may also want the information for any future reference.
Dick
RE: Grout 28day break vs 7day met spec
RE: Grout 28day break vs 7day met spec
What I have had before is that both a 7 day and a 28 day strength were specified and we had low 7 days and okay 28 days or vice versa - the clause was an "and" clause meaning the mortar was in non-compliance if both the 7 and 28 day strengths were not met.
RE: Grout 28day break vs 7day met spec
Thanks,