Technical

Bruce Suprenant, Technical Director, The Voice Newsletter September 2017 When rain falls on fresh concrete, concrete contractors get blamed for not checking the weather conditions and not planning the concrete placement to avoid rain. But tell that to concrete contractors in Seattle or Miami. The rainy season in Seattle includes six months, October through March, with15 days of rain or more, pl...

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Bruce Suprenant, Technical Director, The Voice Newsletter June 2017 The ACI-ASCC 117 Tolerances Committee has just established a subcommittee to consider the effect of movements on tolerances. The current ACI 117-15 does consider the effect of some movements on tolerance measurement. It considers time, within 72 hours, in measuring flatness and levelness either by F-numbers or a 10-ft. straight...

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Bruce Suprenant, Technical Director, The Voice Newsletter ACI’s Technical Activities Committee (TAC) forms technical committees and assigns each a mission. A technical committee mission identifies the knowledge area the committee is responsible for and is usually not document specific. Thus a single committee could develop both a Code or Standard and also a Guide. For instance, ACI Commit...

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Bruce Suprenant, Technical Director, The Voice Newsletter February 2017 Yes, this is concrete at my house in Boulder, CO. Photos A and C are of the “new” concrete placed in 1992. Photo B is the “old” driveway placed in 1967. I bought the house in 1988 so I am responsible only for the “new” concrete. Well sort of. Let’s start with Photo A. There&rs...

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Bruce Suprenant, Technical Director, The Voice Newsletter October 2016 ACI 301-16 “Specifications for Structural Concrete” adopted a new provision for initial curing of flatwork. This provision will increase the cost of performing work for concrete that does not bleed enough to show a visible water sheen. The new provision is shown below: 5.3.6.2 Initial curing of unformed concre...

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Ward Malisch, Concrete Construction Specialist, The Voice Newsletter, September 2016 Have you seen or heard of any requirements for formed concrete surface quality in bid packages? They might be in the form of a reference to ACI 347.3R-13, “Guide to Formed Concrete Surfaces,” in specifications based on models such as AIA MasterSpec™. Sometimes specifications other than AC...

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Bruce Suprenant, Technical Director, The Voice Newsletter July 2016 Shrinkage and temperature reinforcement requirements for design of reinforced concrete structures have been included in the ACI building code since 1928, and haven’t changed much in nearly 85 years. The ACI 318-14 Commentary states that the amounts of shrinkage and temperature reinforcement specified for deformed bars and...

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Bruce Suprenant, Technical Director, The Voice Newsletter June 2016 Shrinkage and temperature reinforcement requirements for design of reinforced concrete structures have been included in the Know the Design Requirements Operable partitions are those that can be quickly put in place or removed and stored to provide flexibility in the spaces typically used for meetings or social functions. Th...

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Bruce Suprenant, Technical Director, The Voice Newsletter May 2016 When is 24.88 equal to 25? The project specification required a specified overall value (SOV) for floor flatness of 25. F-numbers were measured within 72 hours in accordance with ASTM E 1155-14 “Standard Test Method for Determining FF Floor Flatness and FL Floor Levelness Numbers.” Unlike most ASTM standard test ...

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Bruce Suprenant, Technical Director, The Voice Newsletter, April 2016 We have been asked recently about how to join an ACI technical committee. This is a nice step forward from when we used to be asked: Why join an ACI committee?” Now that we passed the “why” hurdle, let’s tackle the “how” of ACI committee membership. The information presented is excerpted fr...

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