If you would take time to read all of the rulebooks that govern the game of baseball, you'd find that the definition of the strike zone is practically the same. But everyone knows that umpires vary their call of the zone based on game conditions and level of play. All coaches and batters ask is that the zone is consistent for the entire game.
The same can be said for the vague set of rules that govern using ready-mixed concrete. True, ASTM C 94 provides the customer a basic set of assurances when it comes to manufacturing and delivering fresh concrete.
But once the material leaves the lip of the chute, a new set of rules takes over. For the most part, contractors and producers have come to rely on the Byzantine suggestions outlined in the various guides the American Concrete Institute publishes
If we're not careful, ready-mixed concrete producers are about to suffer under yet another well-intented rule should a new ACI standard be adopted as it is currently drafted.
Specification for Ready-Mixed Concrete Testing Services (ACI 311.X) is a new proposed document under review by the industry for the next 30 days. In the document's scope statement, the committee states that the proposed specification "sets the minimum requirements for testing of ready-mixed concrete at the project site when field-measured properties and laboratory-measured strength are used as a basis of acceptance of concrete as delivered to the site."
Given the ongoing investigations of mishandled concrete testing procedures in New York City, our industry does need to adopt higher standards of quality assurance. Properly written, this document could help reassure the design community of the concrete industry's commitment to quality. But in its present form, I think the document continues the us versus them relationship of the concrete purchasing process.
As such, I think the document is flawed. In reading the draft, you'll find one important group left out of the whole discussion-the producer.
The document provides no direction that the producer of the material tested be notified of the test results in a timely manner; only the contractor. The authors must feel that all concrete is only purchased by contractors. The proposed standard does not consider a mix purchased directly from the producer.
The document provides no consideration for the producer should an owner select a testing lab that is prejudiced against the producer. The committee must assume that any accredited lab is fair.
And the committee must feel that ready-mixed concrete producers are likely to falsify records. So that even if a lab is certified, accredited, and well-operated, an owner can't have the option to accept the product based on a producer's results. It's ironic that we accept design-build as a innovative way to construct buildings, but we won't allow an opportunity for self-performance on material testing?
Ask yourselves these questions. How much time do you spend trying to settle quality issues raised by poor testing procedures? And how much harder will it be to state your case if ACI introduces a specification that limits your opportunity to be part of the discussion?
It looks to me like some of the big testing labs want more power.
To review the document, visit ACI's Web site at www.concrete.org. Click on "technical" on the menu bar on the top of the page, then scroll down to "upcoming standards." The comment period closes Sept. 17.