Command Alkon Connect

Ideas and information for the Construction and Bulk Materials Industries.

Command Alkon Connect - Ideas and information for the Construction and Bulk Materials Industries.

Just hit 50,000 pagesviews!

Here we are, only a week after my 3rd anniversary with my blog and I have another milestone to announce. My blog has just hit 50,000 pageviews. FYI, it took 22 months to get 20,000 views, but only 14 months to increase to 50,000. I owe it all to my readers, so thank you very much. If you want a summary of my recent posts check out my previous entry about my 3rd anniversary.

Thanks again,


Year 3 and Counting!

Hello, world!

jay_shilstone_HSI begin this post the same way I began my first post, three years ago today. Who would have believed I would have lasted this long writing a blog. My father was always the one who enjoyed writing magazine articles, while I preferred to play with computers. It seems that I found a way to do both, so the apple didn’t fall too far from the tree. I thought today I would give you a view of the results of this blog. Continue reading

Concrete Production – Changing to Ready Mix 2.0

When I first started this blog almost 3 years ago I posted an article entitled “If I Ruled the Concrete Industry”. The article presented 5 changes that I felt needed to be made to the concrete industry. Responses that I received to my most recent post on the fact that concrete producers are not being sent concrete tests as required by the Building Code have pushed me to recognize that the 5 changes I suggested are really symptoms of the same thing, at least here in the U.S. That conclusion is that in the U.S. we are operating under an inappropriate paradigm when it comes to designing, specifying, manufacturing, constructing and testing with concrete. We need to change the paradigm so that the entire design and construction industry takes a more professional approach to the design and use of concrete. Continue reading

Concrete Testing – The Elephant in the Living Room

If you were to walk into an Engineer’s office and tell him to reduce the reinforcing steel in a structure or to cut back on the design strength he would probably think your were crazy (or part of the Mafia). However, many Engineers, Owners, Contractors and Laboratories routinely violate the Building Code and possibly endanger workers and the public. It is time to put an end to this unsafe practice and comply with the Code. What heinous crime am I referring to that endangers the public? It is the practice of not providing concrete test results to the concrete producer.

Continue reading

Concrete Mix Design: Art and Science – Statistical Overdesign Conclusion

I had really planned on stopping the section with my last entry on “Statistical Overdesign by EN-206” but quickly realized there are still a bunch of bits and pieces about this topic still floating around that need to be pinned down. Since the series started there have been updates on ACI 318 and EN-206. Also, there are considerations for other documents, including ACI 301, “Specifications for Structural Concrete” and ASTM C94, “Specification for Ready Mixed Concrete”. Continue reading

Meet Rocky and Learn about Particle Packing

RockyAt the American Concrete Institute Fall 2015 Convention in Washington D.C. I delivered a presentation entitled “Particle Packing from a Rock’s Perspective”. ACI has just posted the presentation on YouTube at If you are looking for a stuffy presentation filled with facts and figures, this presentation isn’t for you. If you want to find out what rocks think about particle packing, drop by and meet Rocky. Hey, its only 12 minutes long. What can you lose?

Concrete Mix Design: Art and Science – Statistical Overdesign using EN-206

My past couple of posts have been about statistical overdesign using ACI 318, so I thought this time I would discuss the overdesign technique used in EN-206. After all, EN-206 uses a similar statistical method to ACI 318, right? Wrong! What started out as a simple 2 hour exercise in paraphrasing EN-206 has turned into a major effort involving about 20 people on 3 different LinkedIn groups. One of my favorite sayings has come to be, “If you want to make God laugh, tell him your plans.” My only consolation from this blog post is that God must have gotten a real belly laugh. Continue reading

Concrete Mix Design: Art and Science – Statistical Overdesign by ACI 318 (Part 2)

When determining the required average compressive strength, f’cr, by ACI 318, the Structural Concrete Building Code, the Code cites the preferred option of using 30 consecutive tests to determine the sample standard deviation, then to use that standard deviation to calculate the overdesign above specified strength, f’c. Fortunately the Code recognizes that not every concrete producer will have 30 consecutive tests for every combination of materials and provides options for other alternatives. In my last blog post we looked at determining required average compressive strength using 30 tests. In this post I would like to examine the other options. (NOTE: There are many details in ACI 318 that are not covered in this post. This post just covers one aspect of ACI 318. If you must develop a concrete mix in compliance with ACI 318 it is strongly suggested that you first obtain a copy of that document. Copies are available from ACI at .) Continue reading

Concrete Mix Design: Art and Science – Statistical Overdesign by ACI (Part 1)

The first question most people ask about concrete is, “How strong is it?” Yes, there are other important characteristics about the concrete, but strength is usually the most important one. In fact, most “hidden concrete”, such as footings, columns, beams and slabs, really is not affected by durability concerns. The primary function of the concrete is to provide support. If we don’t need to worry about maximum water/cementitious ratios for durability concerns, there are other ways to design mixtures just for strength. When concrete has a prior performance history the primary way we determine the cementitious content of concrete is through the use of statistical overdesign techniques, such as are in ACI documents. Continue reading

Concrete Mix Design: Art and Science – Using w/c curves

It sounds so easy to say, “Design a concrete mix using a water/cement ratio curve”, but it isn’t. Finally in this mix design series we are talking about concrete and not just components. However, there are a number of steps we have to go through before we cast our first trial batch. Continue reading