Concrete Corrigendum

The integrity of a building product manufacturer (and of its consultants) requires setting the record straight when it makes an error. I have written numerous articles and pieces of product literature with statements similar to the following:
"When portland cement hydrates, it yields calcium silicate hydrate (CSH) crystals that interlock to give concrete strength." (Chusid, Structural Engineer)
This is incorrect. CSH is a gel, not a crystal.
"Illustration of various steps in the digital-image-based cement hydration model showing, from bottom to top, initial cement particles in water (black), highlighting (white) of all cement particle surfaces in contact with water, generation of one-pixel diffusing species, and hydrated images at ~32% and 76% hydration, respectively (C 32 is red, C2 S is blue, C3A is bright green, C4AF is orange, gypsum is pale green, C-S-H is yellow, CH is dark blue, and aluminate hydration products (ettringite, monosulfoaluminate, and C3 AH6) are green)." (Bentz, Journal of the American Ceramic Society)
While conducting research prior to writing the various publications, I have seen hydrated cement paste described as both crystalline and gelatinous. It was easier for me to visualize the former because I am familiar with hard, dense, and strong crystals such as quartz and table salt. My mental image of a gel, however, was gelatine -- a substance too insubstantial, I thought, to explain concrete.

I now appreciate that, with respect to cement hydration, "The C-S-H gel is not only the most abundant reaction product, occupying about 50% of the paste volume, but it is also responsible for most of the engineering properties of cement paste. This is not because it is an intrinsically strong or stable phase (it isn't!) but because it forms a continuous layer that binds together the original cement particles into a cohesive whole." (Thomas and Jennings) Cement paste's properties as a gel help explain phenomena such as concrete creep (deformation over time) and swelling that occurs when alkali-silica reaction causes concrete to crack.

Perhaps only petrologists can fully appreciate the difference between a crystal and a gel, yet it is key to understanding concrete's performance or failure. It is also a crucial distinction for specifiers trying to interpret competing claims by producers of admixtures, supplementary cementitious materials, and concreting processes.

I thank Ward Malisch, PE, PhD, FACI, technical director for American Society of Concrete Contractors, for explaining this to me during a conversation at the recent World of Concrete tradeshow.

By the way, "corrigendum" has a similar meaning to "erratum" except that the former is best applied to an error by an author while the latter is an error in the production of a publication.

The Wrath of Abibarshim

Recently excavated clay tablets shed new light on the most famous engineering failure in antiquity. Although some of the words are conjectural, this translation contains a clear message for modern engineers. Do you know someone who might benefit from this voice from the past?
as heralded by PRODUCTION ENGINEERING Magazine
I, Abibarshim, Great King, King of Kings, Ruler of Kish, Babil, Agade and Sankhar, and of the regions across the Hilla, conqueror of Ninevah, destroyer of Sepharia, having striven mightily and met with grief, lay down this Code that ye may not also strive mightily and meet with grief, nor fall flat on thy ass.

For I, Abibarshim, King of Kings, and all that, did buy many Aethyopeans and hire many artisans and scribes and masons and Makers of Engines and Designers of Buildings. And great was their craft and great their number, which was one hundred and forty four thousand, give or take a few job-shoppers. Yea, they did strive mightily, too, for they knew what would happen if they strove
not mightily. And the name of my capital improvement project was the Tower of Babil.

Yea, great was their craft and wonderful to behold what the Designers of Buildings wrought on the papyrus. All who looked thereon did marvel at their genius. I, Abibarshim, did also look thereon and did declare their designs to have much nift.

But many days did pass, and many times did the moon wax and wane, and the tower was not yet builded.

So I, Abibarshim, King of Kings, did hie me to the palace by the Arakhtu where dwelt the Designers of Buildings and Makers of Engines. And there I found
not Designers of Buildings and Makers of Engines, but Drinkers of Coffee and Tellers of Tales (whom men call hurlers of bull dung). So I vented my royal spleen, which did perturb them mightily.

"Look here, O King, etc.," said the Chief of the Makers of Engines. "Some things can't be rushed. If thou wantest us to get thy bloody tower builded on time, then thou hadst better give us a little respect. For canst thou build thy tower without us?"

"But I have given thee this palace in which thy work may be done, and I pay thee many talents of gold and silver, plus all the usual fringies. What more wouldst thou have me do to get this project moving?"

"Well, thou canst start with alabaster lamps for the draughtsmen," saith the Chief of the Makers of Engines, refilling his cup. "And maybe draughting instruments of silver and electrum…"

"Thou shalt have them. Just get my tower builded." And I, Abibarshim, King of Kings, did depart the palace of the Makers of Engines with my tail betwixt my legs.

And many days did pass, and many times did the moon wax and wane, and the tower was still not yet builded. So I, Abibarshim, did corner the Chief Scribe and ask him, "What goeth on here?"

The Chief Scribe fell to his knees and said: "O Great and Merciful King, the Makers of Engines give us scrolls of materials for to purchase. But, verily, no man knoweth what the scrolls signify, save the Makers of Engines themselves. For they call not a spade a spade, but call it here a delver and there a digger and another place an entrenching tool and yet another a geovolvometer, so that the scroll of material agreeth not with the design papyrus. And strange to behold is their numerology."

So I, Abibarshim, gave certain orders to try to keep the Makers of Engines from creating their own language, saying, "How did it come to pass that those who have such swiftness of mind, even as the gazelle, lack the sense of geese?"

And many days did pass, and many times did the moon wax and wane, and the estimate did wax and never wane, and the tower was not yet builded.

So then I did ask the Chief Mason, "What giveth?" and he, throwing himself prostrate before me, spake thus:

"O King, every day we toil from dawn until the dusk! Every week the Makers of Engines say they have wrought new and niftier designs, of which we knew not, and what we have builded hath been fashioned into obsolete papyri. Then my team teareth down and starteth over, O Great King, Merciful King, King of Kings…"

So I, Abibarshim, gave certain orders that did fix those designs thenceforth.

But many days did pass, and the tower did rise slower than sap rolleth down the bark of a tree.

So I, Abibarshim, did seek out the Chief Aethyopean, who seemed to know where it's at, and asked, "How come no tower?"

And he did answer, "O Great and Merciful King, I be running short of bolt tighteners."

"Well, buy some more!"

"I have, O King, but each one either getteth used up or runneth off as soon as he learneth his trade."

"Which is?"

"The Makers of Engines have designed the granite facing panels such that no man hath arms long enough nor thin enough to reach the bolts. Thus each panel requires that a bolt tightener crawl behind and affix the bolts."


"So then he cannot get back out, O King, but is entombed there forever."

I, Abibarshim, did then call for a redesign which cost us three months and one thousand gold talents. But the days did pass and the tower had attained only four tiers in height. So I did go to the Chief Scribe to inquire why.

"O King, we have been awaiting, lo, these many months, the columns of Corinthian marble for the fifth tier."

"Is marble from Corinth so hard to find, then?"

"Nay, Sire, but the Corinthian stone cutters make columns only in heights which be whole numbers of cubits. And the Makers of Engines have specified cubits which be twelve cubits plus eleven-seventeenths part of a cubit. Such columns are not to be found in all of Corinth as an off-the-shelf item."

"Well, let's just change the drawings and round them off to thirteen cubits even."

"Nay, Sire, for they must match unto the interior columns, which are bought pre-cut from Ionia and which we have aplenty."

"Okay, we'll cut the Ionian columns down and go unto twelve cubit columns all around."

"Nay, for the Ionian columns be all of one piece with their capitals. To shorten them would mean cutting off their capitals."

"What in the name of Marduk is wrong with that? We can just fit new capitals on top of the shortened columns."

"Nay again, Sire. The entire structure unto the very top is designed around monobloc capitals. To add new capitals would weaken the fifth and higher tiers and require a complete redesign!"

I, Abibarshim, King of Kings, avouch that Makers of Engines, for all their craft, know not how to fly. For surely the Chief of the Makers of Engines and all his men would have flown down, had they known how, from the fourth level of my tower, from which parapet I, Abibarshim, King of Kings, had them flung.

Therefore have I, Abibarshim, King of Kings, created this Code and ordered it displayed at the Coffee Machine and all other places where hangeth out the Designers of Buildings and Makers of Engines.
The Code of Abibarshim
I. Once thou decidest what name to call a thing, that shall be its name forever after, until eternity passeth. Nor shall thou call any other thing by that name, for each thing shall have a name unto itself.

II. And in like manner shall be the enumeration of each thing.

III. Continue not to design a thing unto perfection, for, verily, an ounce of timeliness is more valuable than a pound of perfection. Once thou hast approved a design, go not back and improve it, unless of necessity most dire.

IV. Cover not thy tracks but make thy calculations plain, that those who follow thee may trace any error to its beginning and thus set it and all its brethren upon the path of righteousness.

V. And mock not the necessary papyrus work, for it is the handmaiden of what thou createst in stone and iron. Completest all thy papyri as thou goest and hoardest them not as a surprise for manufacturing.

VI. Attendest first to that which hath the most importance. Waste not time fixing thy wind to heavy papyrus with wire.

VII. He who designeth without a plan is like he who rusheth forth into darkness without a torch. Rush not ere thou knowest whither, for there are many snares and pitfalls in the dark, and wild beasts to reach up and bit thine ass or camel on the path named Critical.

VIII. Specify not odd-ball sizes and kinds of things, but design unto standards, that the scribes may buy stuff off-the-shelf and dabble not with specials.

IX. Design not assemblies which require four arms to put together or operate. Verily, the guy we hire in these days hath not four arms but ten thumbs.

X. Remember well that all which thou designest shall be a balance of time and cost and quality and function. If thou attendest not to all four, then miserable shall be thy lot and brief thy employment (unless thou knowest how to fly).

NPR's Social Media Policy is Worth Emulating

NPR has been gracious enough to make its Social Media Policy available online. While much of it is centered around ethical journalism, building product manufacturers would do well to examine it. As more and more relationship-building happens online, companies need to participate, and to do so wisely.

Increasingly, lines between employees' business and personal lives are blurred, and social media is an especially blurry place. One case study, entitled "There is No Privacy on the Web", illustrates any company's nightmare:

Imagine, if you will, an NPR legal correspondent named Sue Zemencourt. She’s a huge fan of Enormous University’s basketball team and loves to chat online about EU. She posts comments on blogs under the screen name “enormous1.” One day, an equally rabid fan of Gigormous State (“gigormous1”) posts obnoxious comments about EU.
Sue snaps. Expletives and insults fly from her fingers on to the webpage. They’re so out-of-line that the blog blocks her from submitting any more comments — and discovers that her i.p. address leads back to NPR. The blog’s host posts that “someone at NPR is using language that the FCC definitely would not approve of” and describes what was said. Things go viral.
The basically good person that she is, Sue publicly acknowledges and apologizes for her mistake. But that doesn’t stop The Daily Show from satirizing about the “NPRNormous Explosion.”
Damage done.
Be circumspect about your behavior, even when the exchange feels private or anonymous. Even an email to a trusted recipient can be made public, with or without the recipient’s knowledge or consent.
In fact, a big part of the chapter on "Honesty" is, in fact, the putting on and taking off of the work identity. Because many NPR employees use their real names on the radio, they're encouraged to use screen names that don't identify them in the personal realm.  And when they're off duty and they find themselves working, they must put their work identity back on.
If in their personal lives NPR journalists join online forums and social media sites, they may follow the conventions of those outlets and use screen names that do not identify who they are. But we do not use information gathered from our interactions on such sites in our reports for NPR. If we get ideas for stories, we treat the information just as we would anything we see in the “real world” — as a starting point that needs to be followed by open, honest reporting.
Your business, even if it's far less public, may wish to explore policies about how employees present themselves in their off-work interactions. For instance, American Widget Co. may decide to allow its product reps to use their real names online in private, but ask that they not identify their employer in their Facebook or other profiles. Or, they may simply prohibit the use of AmWidget or AWC in screen names except for social media used for business. By the same token, when representing Widget, employees should make that clear in their profile names and follow the company's communication policies.

The best part of NPR's guidelines, in my opinion, is their understanding that social media conduct continues to be a moving target. Even if a manufacturing company's policy is far simpler, NPR's review process is worth emulating:
We rely on the contributions of every NPR journalist to ensure this handbook remains current and relevant to the situations you face each day. If you encounter decisions for which you feel the guidance in this book is inadequate, have questions about interpreting what you read here, or suggestions for how to improve the handbook, we encourage you to send a note to Ethics.
Twice a year, the Standards and Practices Editor will convene an ethics advisory group to consider all suggestions, review the Handbook, and make any additions or revisions necessary.
How do you want to be seen online? Take a look at your company through this lens and see if you're inspired to make any changes to your social media policies.

Ethics and Advertising Sales Reps

The sales rep for a major architectural magazine called me today to see about getting business from one of my clients. In a candid conversation, we strategized what might be best for my client and how to present that to the firm. We also exchanged news and views about players in the industry; I suggested a firm that might be open to advertising, and he pointed me towards a company that might need marketing consulting support. All is well and good.

The rep then told me that my client's competitor had just made a major advertising purchase in the magazine.

At first, I was elated. This was valuable marketing insight into what a competitor had planned.

But then, I realized that the rep had just violated the confidence of one of his/her publisher's clients.  This makes me wonder -- can I trust the rep or the publisher with insider news about what my clients are planning?

The ethical slopes are steep and slippery. Beware.

Environmental Risks Not Immediately Apparent

Manufacturers often rush to launch new products, hoping to gain a competitive edge. Yet the environmental risks of a new material or technology are not always apparent until the product has been on sale for a period. This is a problem even in industries such as pharmaceuticals in which products must undergo extensive testing and regulatory review for both effectiveness and safety.

It is an even bigger risk in the construction products industry. New building products may require testing to demonstrate certain aspects of safety -- such as fire resistance -- in order to comply with building codes. Yet there are not industry-wide  protocols for testing the environmental impact of a product, nor regulations mandating prior approval before marketing.

A case in point is nano-sized particles of titanium dioxide. The material has impressive potential for reducing airborne pollutants and making concrete self-cleaning. A marketing director promoting the product once assured me the compound is inert, and saw no reason to delay the product's introduction until it could be tested for impact on ecosystems. When he boosted that he could eat a spoonful without ill effects, I responded, "Yes, but you are not a coral polyp."

Now, new research suggests my concern was not unwarranted:

According to a new Northeastern University study, titanium dioxide nanoparticles (nTiO2) can disrupt photosynthetic organisms vital to aquatic ecosystems. Long used in paints, coatings, cement, and tile to create bright white coloring, titanium dioxide is now used in nanoparticle form in cosmetics, sunscreens, food coloring, and even building products, particularly white concrete products that are claimed to clean the air.

April Gu, Carla Cherchi, and other environmental engineers studied how nTiO2 affects one blue-green algae organism that contributes to aquatic nitrogen and carbon cycles. The researchers found that algae growth was reduced by 90 percent and nitrogen fixation activity was diminished when the organisms were exposed to nTiO2 at levels similar to those found in wastewater. Effects increased with exposure time and nTiO2 concentrations. The laboratory study did not evaluate the effect of titanium nanoparticles in the environment, or whether such particles are released from common products. For more information visit
Elsewhere, I have suggested prudent measures that can be taken to use TiO2 in building products, even while further environmental safety research is being conducted. The point of this post is to urge all members of the construction industry to proceed with caution when investigating new materials that have not been rigorously tested for environmental safety.

Greenwash of Week - Cement Industry

As an architect, I was trained that my first responsibility is to be a good steward of the environment. I believe this should also be the first responsibility of everyone involved in the construction industry.

I feel shocked and saddened, then, when I read a news story like the following:
N.Y. cement factory plans to fight new EPA regulations
A New York-based cement plant, LaFarge, along with other companies, opposes new EPA regulations that require mercury-emissions reductions at cement plants. Portland Cement Association, an industry trade group, says the emissions limits are too low and it will be difficult to meet the requirements. However, environmental groups say that noncompliance will lead to more toxic pollution. Public News Service (11/09/2010)
LaFarge's website proclaims that the company "is convinced that sustained economic growth cannot occur without social progress, environmental protection and respect for local communities." Too bad the marketing and operations departments in the company don't communicate with each other.

PCA's website posits that the cement industry. "is not content to simply have a green end product." This leaves open for interpretation whether "green" is a synonym for the environment or for profit.


I offer a strategy, however, that will solve cement plant pollution without requiring the EPA to place caps on mercury emissions. All we have to do is require the executives of cement manufacturing companies and associations -- and their spouses and children -- to live within a mile downwind of their plants.

Certainly, their tune about the cost/benefit of emissions will change as a result.
For more on this controversy, see my previous post on Cement Emissions and Social Justice.

At Least it's Not Politics

Building product marketing can be fierce, but at least its not as nasty as the marketing of political candidates. 
Continuing a family tradition of marketing excellance, my son, Andrew Chusid, managed the successful reelection campaign for Illinois State Representative Carol Sente. In the closing weeks of the campaign, unidentified parties placed posters throughout Sente's district that linked her to an unpopular local politician facing recall.

According to the local newspaper, "'Carol was disgusted by these dirty tricks,' Chusid said."

There may be dirty tricks played between bidders or subcontractors, and building product manufacturers often make technical or judgment errors in their marketing collateral. Overall, however, I am grateful for the integrity shown across the board by building product marketing. At least it isn't like politics.