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Grout 28day break vs 7day met spec 4
- Thread starter njcadz
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2
- #2
concretemasonry
Structural
You should probably make the 28 day breaks for a number of reasons -
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
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
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1
- #3
GeoPaveTraffic
Geotechnical
I agree, break the 28 day samples. No one may care about the results, but you can bet that if there is a future problem everyone will want to know what the 28 day break was.
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1
- #4
From a contractual point of view, if the acceptance criteria is the 28 day strength, it matters not what the 7 day strength is for only the 28 day strength can "judge" the mortar (or concrete).
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.
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.
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