Modern concrete plants can control mix proportions very closely, so strength variations should be minimal - other factors being equal.
"other factors" have a habit of not being equal and sometimes strengths
are lower than normal for no obvious reason.
This can mean sleepless nights for the technical team tasked with identifying the problem and fixing it (that's probably you, as you are reading this).
the concrete in question is being used in a large-scale building
project of national importance, or if your company has had to suspend
production of concrete products, or if you supplied concrete for the
foundations of a large and expensive building that now has cracks in the
walls, the pressure will be on. But I can help.
Here's the thing: when cement manufacturers, ready-mix concrete producers and people who make concrete products have difficult strength problems, what do they do?
They come to me.
That's because much of my work since the late 1980s has been examining clinker, cement and concrete for these clients to identify the cause(s) of low strength. I've looked at hundreds, probably thousands, of concretes, cements and clinkers with a wide range of problems. One factor most of them had in common, though, was the pressure the client was under to resolve the issue. Fast.
I can tell the stress some of my clients are under by the number of times in a day they phone or email me to ask about progress. I really feel their pain, and I can also feel the CEO or Managing Director breathing down their necks. (Sometimes the corporate legal department too, if there might be liability issues).
I've written a book that will help you solve low strength problems
The working title is: "Low concrete strength? 27 Potential cement-related causes and how to identify them". It will be available soon.
Compared with the free ebook "10 Causes..." that you can get when you subscribe to "Cembytes", our Newsletter, this new book describes many more potential causes of low strength in concrete that may be related to cement. It also shows how each cause may be identified and possible difficulties that may arise.
Some of the potential causes described are due to intrinsic problems with the cement or clinker. Others are cement-related but the cement itself is not the problem; obvious examples are insufficient cement in the mix or excessive water-cement ratio.
If you would like to know when the book is ready (without commitment) just leave your email address using the form below.
Estimated publication is Spring 2019. It will be available first in an ebook version. A printed version may be available later.