Excess Concrete Strength Concerns
Excess Concrete Strength Concerns
(OP)
Here's one for you. I've never seen this happen in the 41 years I've been practicing. Just received compression test results for test cylinders taken 28 days ago. The design strength for wall footings was specified to be 3,000 psi. The cylinder test results indicate strengths ranging from 6,000 to 7,000 psi. The results average about 240% above the specified design strength. Should I be concerned about this? The higher strengths would generally affect development lengths but would tend to shorten them. The reinforcing is already fabricated so that is not a concern. Does anyone see this as a concern?






RE: Excess Concrete Strength Concerns
There is ample precedent in the history of science for the overwhelming bulk of the scientific community strongly believing in imaginary entities postulated by a favovered theory. -Michael Behe
RE: Excess Concrete Strength Concerns
BA
RE: Excess Concrete Strength Concerns
RE: Excess Concrete Strength Concerns
BA
RE: Excess Concrete Strength Concerns
RE: Excess Concrete Strength Concerns
Whats a little extra cement & additives among friends?
RE: Excess Concrete Strength Concerns
Off the top of my head: I cannot think of too much. I seem to remember it can (under certain circumstances) drive down the effective moment of inertia. It’s also not quite as ductile as it was (for seismic purposes).
RE: Excess Concrete Strength Concerns
Was a mix design required and submitted for approval on this project?
Engineer and international traveler interested in construction techniques, problems and proper design.
RE: Excess Concrete Strength Concerns
RE: Excess Concrete Strength Concerns
Having too much cement isn't always a good thing.
But for general footings I wouldn't think there'd be much concern.
RE: Excess Concrete Strength Concerns
I agree that the supplier may be having quality control issues that should be addressed.
RE: Excess Concrete Strength Concerns
RE: Excess Concrete Strength Concerns
RE: Excess Concrete Strength Concerns
RE: Excess Concrete Strength Concerns
RE: Excess Concrete Strength Concerns
RE: Excess Concrete Strength Concerns
Also, find a way to get a guarantee that the approved mix design was actually delivered. With the current dispatching of concrete is is usually easy to have the mix design number on the delivery ticket. That has been common for highway work in some states for years, since the batching is usually a part of the information flow to generate a delivery ticket with copies for the contractor also.
Dick
Engineer and international traveler interested in construction techniques, problems and proper design.