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nonshrink grout vs type i grout
my contractor has decided to use type i cement grout underneath the baseplates of our 5 story building rather than use non-shrink grout spec'd in our drawings conforming to astm c1107.
we are at a point where we need to find some evidence that his grout is unacceptable. what makes it more complicated is that we are on the same team. so, does anyone know of a reference that shows that non-shrink grout is the only acceptable type or that masonry grout is not acceptable?
again, i am not looking for anything but references. i fully understand what non-shrink grout is intended for and how it acts, but i'm not finding many references in the literature.
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if his grout shrinks, which all portland cement based grouts do, than it is unacceptable. this should be a no brainer, no shrink is always required.
why is the contractor deciding what to use?
does your project have any specifications? you will be hard pressed to find a "type i grout" that meets any specifications for grouting under bearing plates unless it is a casual use. to be a nit-picker, the only question should be whether the grout be metallic or non-metallic.
masonry grout using type i cement is a totally different material that could not be used in this application.
dick
being on the same team with a contractor who wants to cut corners is a bear. here is where your mettle is tested. talk louder and louder until he listens.
alright, looks like everyone missed my point. the contractor is not fighting me on this. i just need references if they exist.
if there is no conflict then surely a lack of evidence that type i is acceptable would be enough.
i don't think that shrinkage is the issue here. after all, if the grout shrinks 2-3%, that's peanuts compared to normal footing settlement. compressive strength is the issue. grout under bearing plates should reach 5000 psi (or your footing strength) in 7 days (your spec should state that). masonry grout is often only required to reach 2000 psi at 28 days. so, if the grout mix doesn't meet your specified strength, it is unacceptable.
i think shrinkage is an issue.
if the steel fabricator uses leveling nuts and the grout shrinks the anchor bolts will transferring the axial load instead of bearing through the grout. if the fabricator uses leveling plates and the grout shrinks the anchor bolts will probably not be properly tightened anymore. the latter case would depend how soon the columns are erected after the grout/leveling plates are set.
eit-
you're right. |
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