Arizona Chapter
American Concrete Institute

News 

  • 29 May 2017 12:51 PM | Beth Britt (Administrator)

    Hot Weather Concreting—Methods for Success

    04/28/2017


    Injection of liquid nitrogen into concrete truck

    As a global leader in advancing concrete knowledge, ACI’s goal is to keep concrete industry professionals up to date with the latest information.

    For example, here’s a recent exchange from ACI’s Q&A section:

    Q. “What are the ACI building code requirements for placing concrete in a tropical climate? Some people in our office say we should specify a maximum permissible concrete temperature of 90 ºF (32 ºC). Others say a temperature higher than 90 ºF (32 ºC) is allowable if the concrete contains a set-retarding admixture.”

    A. ACI 301-16 “Specifications for Structural Concrete” and ACI 305.1-14 “Specification for Hot Weather Concreting” limit the maximum concrete temperature to 95 °F (35 ºC) at the time of discharge. This limit is for general types of hot weather construction such as pavements, bridges, and buildings, not mass concrete.

    Hot weather concreting is defined by ACI as “one or a combination of the following conditions that tends to impair the quality of freshly mixed or hardened concrete by accelerating the rate of moisture loss and rate of cement hydration, or otherwise causing detrimental results: high ambient temperature; high concrete temperature; low relative humidity; and high wind speed.

    Various adverse effects on the properties and serviceability of concrete are brought on by hot weather. Just one of those is the effect on strength—concrete mixed, placed, and cured at elevated temperatures normally develops higher early strengths than concrete produced and cured at lower temperatures.

    To connect to ACI International's website to see more on this document, click here


  • 12 Dec 2016 10:30 AM | Beth Britt (Administrator)

    YOU CAN’T COMPETE WITH THE REAL THING This is World of Concrete—a firm foundation for the entire concrete and masonry industries and the first and most important annual international event of the year. It’s everything you need and nothing you don’t. Put in four high-efficiency, low-cost, smart-work days at WOC 2017 and you’ll see your bang/buck ratio go through the roof.

    2017 WOC Exhibit Hall Hours
    Tuesday, January 17-Thursday, January 19
    9:30 am -5:00 pm
    NEW! Friday 9:00 am - 12:00 pm

    Exhibits Only
    $70 by 12/1/16; $85 after 12/1/16
    Exhibits Only Spouse
    $70 by 12/1/16; $85 after 12/1/16
    Shuttle Bus (If NOT booking hotel through WOC Housing)
    $30 by 12/1/16; $40 after 12/1/16
    WOC 3-Hour Seminars
    $145 by 12/1/16; $175 after 12/1/16
    WOC 90-Minute Seminars 
    $105 by 12/1/16; $135 after 12/1/16
    WOC 4-Hour Certification Seminars
    $190 by 12/1/16; $225 after 12/1/16
    Super Pass 1
    $425 by 12/1/16; $550 after 12/1/16 (Incl. FREE Exhibits-Only)
    Super Pass 2
    $425 by 12/1/16; $550 after 12/1/16 (Incl. FREE Exhibits-Only)
    Super Pass 3
    $525 by 12/1/16; $650 after 12/1/16 (Incl. FREE Exhibits-Only)

    2017 WOC Education Program Hours:
    Monday, January 16 (Pre-show Education all day)
    WOC 3-Hour Seminars: 8:00 am - 11:00 am; 1:00 pm - 4:00 pm
    WOC 4-Hour Certification Seminars: 8:00 am - 12:00 pm; 1:00 pm - 5:00 pm
    WOC 90-Minute Seminars: 8:30 am - 10:00 am; 10:30 am - 12:00 pm;
             1:30 pm - 3:00 pm; 3:30 pm - 5:00 pm

    Tuesday, January 17 - Thursday, January 19

    WOC 3-Hour Seminars: 8:00 am - 11:00 am
    WOC 4-Hour Certification Seminars: 8:00 am - 12:00 pm; 1:00 pm - 5:00 pm
    WOC 90-Minute Seminars: 8:30 am - 10:00 am; 1:30 pm - 3:00 pm

    Friday, January 20
    WOC 3-Hour Seminars: 8:00 am - 11:00 am
    WOC 90-Minute Seminars: 8:30 am - 10:00 am

    Something for everyone:

    WOC will once again feature special product and action areas, including The Producer Center, a marketplace of materials, equipment, demos, and seminars for concrete producers; Material Handling, offering trucks, excavators and more for material delivery, distribution, concrete placement, and earth moving; Concrete Repair & Demolition, housing a display of surface preparation equipment, scarifying, grinding, sawing equipment, and other demolition products; World of Masonry, showcasing products, tools, information, and technology for masonry professionals; Technology for Construction, featuring the newest products and tools for the commercial construction industry from top information technology and systems providers; and Concrete Surfaces & Decorative showcasing the popularity of decorative concrete for both commercial and residential applications. Precast was launched in 2016 and highlights the latest products and technologies in the precast/prestressed sector.

    NEW FOR 2017
    Concrete Masonry (North Hall)
    This area showcases everything for the producers of concrete masonry (block, segmental retaining wall units, veneer, slabs, pavers, and more.)
    • Admixtures
    • Equipment & Supplies
    • Pigments

    Concrete Reinforcement (North Hall)
    Features the leaders in concrete reinforcement showcasing reinforcement bending, cutting, straightening, and fabricating machinery.
    • Reinforced positioners & locators
    • Epoxy-coated, steel, glass fiber, galvanized bar
    • All types of reinforcement accessories


    BENEFITS OF ATTENDING WOC:
    See it all in one place.
    Find everything you need to win more jobs, make more money and streamline your business.
    Get connected.
    Make new contacts and strengthen your industry connections.
    Work smarter.
    Learn how to work leaner, get the safety training and courses you need in today's economy.
    Get hands-on.
    See, touch and test the latest products under real-world, jobsite conditions.
    Find new opportunities. Capitalize on the trends that will drive future markets and provide opportunities to profit.
    Get your questions answered.
    Attend expert-led seminars for the new skills, practical solutions and creative strategies to improve your business.


    Please note: All info is subject to change. During normal show hours, persons 17 years-old and under will be admitted only with parental supervision. THIS RULE IS STRICTLY ENFORCED. Persons 18 years-old and over must register and pay in order to receive a badge.  The use of Segway and Segway-type units are prohibited on the show floor unless the Segway is identified with and ADA placard.

    USE REGISTRATION CODE A21 to receive discounted rate!

    Go to Registration Page

  • 07 Mar 2016 8:20 AM | Beth Britt (Administrator)
    It has been my honor to represent the American Concrete Institute as its 92nd President during the past year. I have interacted with members from across the Institute and met people from around the world, and they all shared a vision for improving our infrastructure, and the overall quality of life, through the use of concrete.

    2015 was a very strong year for ACI, and I am pleased to share with you some key metrics:


    All of these achievements, and many others, are the result of countless hours from our volunteer members. Thank you for your interest in and commitment to the Institute.

    As a member of technical committees for more than 30 years, I was quite familiar with ACI’s reputation as a source of state-of-the-art technical information. The importance of providing unbiased technical information continues to increase with the development of new products and materials. ACI members continue to impress me with their commitment to vetting technical information thoroughly and developing comprehensive design standards to facilitate safe and reliable use of concrete.

    I have also been extremely impressed with the ongoing activities within ACI’s educational committees. ACI is moving from in-person seminars related to a single technical document to a suite of online educational options. This change allows concrete professionals to obtain the technical information that they need in a timely fashion and on a schedule that can be accommodated within their busy careers. By all reports, ACI University and the certificate programs have been extremely well received by ACI members, and I look forward to further expansion of options in this area.

    "ACI members continue to impress me with their commitment to vetting technical information thoroughly and developing comprehensive design standards to facilitate safe and reliable use of concrete."

    Perhaps the thing that surprised me the most was the passion exhibited by ACI members and Chapter members in the area of certification. A severe shortage of workers in the U.S. construction industry is projected within the next 10 years, but through its certification programs ACI is dedicated to ensuring that the concrete workforce of the future is well-trained and ready to move our industry forward. In addition, the development of country-specific certification programs has the potential to improve the quality of concrete construction worldwide.

    I would like to extend my sincere thanks to Past Presidents Jim Wight, Anne Ellis, and Bill Rushing. Each of you has served as a mentor for me. Your advice and insights have been instrumental to me during the past year. Vice Presidents Mike Schneider and Khaled Awad bring new ideas and insights to the executive committee, and I am confident that they will provide strong leadership of ACI. Finally, I want to thank all the ACI staff—an amazing group of dedicated professionals.

    Thanks again for this opportunity. I look forward to seeing many of you at the ACI Convention in Milwaukee, WI, this spring.

    Sharon L. Wood

    Sharon L. Wood

  • 29 Sep 2015 12:46 PM | Beth Britt (Administrator)

    A Performance-Based Approach to Hot Weather Concreting, Part 1 of 2

    Tuesday, November 10, 2015 8:30 AM - 10:30 AM, GOVERNOR'S SQUARE 12

    This session focuses on new developments, common practices, innovative technologies, and challenges related to design, construction, and performance of concrete in hot weather.
    By attending this session, attendees will be able to:
    1. Identify options for dealing with placing, finishing, and curing concrete in hot weather;
    2. Learn about new ideas and innovative technologies available to improve concrete performance in hot weather;
    3. Understand common construction practices and challenges with concrete in hot weather; and
    4. Recognize benefits of knowing ways to optimize design and construction of concrete in hot weather.

    Model for Early-Age Rate of Evaporation of Cement-Based Materials

    Presented By: Mehdi Bakhshi
    Affiliation: AECOM
    Description: Early-age cracking affects the structural integrity of concrete structures and, if not inhibited, would lead to a reduction in service life. Plastic cracks are observed in the first few hours after placing the concrete, a time period well within the initial stages when the drying process is controlled by the rate of evaporation of concrete surfaces, which is roughly constant and similar to the rate of evaporation from water surfaces. In the absence of a theoretical method, this rate is commonly estimated using a nomograph based on Dalton’s law. A fluid mechanics-based approach for water evaporation based on the boundary-layer theory, mass transfer, diffusion, and convection is presented. A parametric study is conducted on the effect of boundary-layer temperature, wind speed, relative humidity, and evaporation characteristic length on the calculated evaporation rates. Predicted evaporation rates are verified by recent experiments. Results show that given appropriate environmental parameters, evaporation rates can be predicted with a good degree of accuracy.

    Dealing with Hot Weather Concrete: Specifications, Materials, Operations and Other Challenges

    Presented By: Oscar Antommattei
    Affiliation: Kiewit Corp - Kiewit Infrastructure Engineers Co
    Description: Placing concrete in hot weather conditions is known to pose unique challenges. Specifications can include restrictive and prescriptive requirements that result in additional challenges to the field operations. Technologies available to the concrete industry facilitate concrete construction in hot weather. Recent developments in admixtures can also be beneficial in improving concrete performance in hot weather. Concrete mixture proportions must be designed to meet specified requirements, but also to properly perform in the field and meet construction demands. This presentation provides fundamental knowledge and experiences to consider for concrete in hot weather.

    Specifying, Proportioning and Producing Rapid Strength Concrete with Consideration for Ambient Conditions

    Presented By: Boris Stein
    Affiliation: Twining Inc
    Description: Proper preservation and rehabilitation strategies extend service life of concrete pavements and structures and are essential for enhancing sustainability of concrete transportation infrastructure. The use of rapid strength concrete (RSC) for these purposes allows for minimizing the impact on traffic. Acquired experience suggests that for the best quality and longevity RSC must be designed for: (i) constructability; (ii) required rate of strength gain; (iii) ambient conditions during construction and exposure conditions in-service; (iv) early age volume changes; (v) permeability; and (vi) durability. The paper discusses (i) principles of specifying , proportioning and producing of RSC with consideration for the impact of ambient conditions on constructability and pace of construction, (ii) summarizes laboratory and field data addressing impact of ambient conditions on performance of RSC; (iii) discusses best practices; and (iv) illustrates recommended approaches with case studies of specific projects.

    Using Workability Retaining Admixtures in Hot Weather Concreting

    Presented By: G Terry Harris
    Affiliation: W R Grace & Company
    Description: Historically increased dosage rates of Retarding or Extended Set Control admixtures were used to extend slump life in hot weather. Now, workability retaining admixtures allow us to extend the slump life in concrete mixtures without extending the set time significantly. Recently these workability retaining admixtures were used in drill shaft concrete to extend the slump life without excessive retardation.

    How Does Hot Weather Placement Impact Transport, Durability, and Performance Specifications

    Presented By: W Jason Weiss
    Affiliation: Purdue University
    Description: High temperature curing (at 50 ± 2 °C) was evaluated in comparison to conventional curing for use in a Nernst-Planck service life prediction model (Stadium®). Curing at 50 °C accelerated the hydration reaction as expected. When the samples were stored in lime water, the microstructure formed at the higher temperature showed an increase in total porosity, chloride diffusion coefficient, and permeability at the same maturity. The impact of these inputs was assessed for service life prediction for the example used here resulted in a prediction of corrosion initiation times that were approximately 30 % earlier than those predicted using samples moist cured at 23 ± 2 °C. The results indicate however that the moisture conditions dramatically impacted the influence of temperature as samples with a higher degree of saturation were more prone to damage caused by high temperatures presumably due to the coefficient of thermal expansion of the water.

     

    To Register:  www.concrete.org

  • 02 Sep 2015 1:02 PM | Beth Britt (Administrator)

    Please join other industry professionals for the Bi-Annual Concrete Convention and Expo in Denver, Colorado November 7-12th, 2015.  Registration is online with an early bird discount through October 11th.  After that date and on site, the cost will increase $100.  For the First time there will be an Excellence in Concrete Award banquet representing the winning projects from around the globe for 2015.  There will also be a Concrete Sustainability Forum on Wednesday, November 11th where Global experts will update attendees on new, innovative technologies, sustainability assessment systems, and sustainable design from around the world.  You won't want to miss this Free Forum when you attend the Convention.  Click the link below for more information and registration details.

     

    https://www.concrete.org/events/conventions/currentconvention.aspx
  • 02 Sep 2015 12:44 PM | Beth Britt (Administrator)

    On August 18, 2015 our Chapter held its annual market forecast meeting to kick off our 2015-16 program year.  Cliff Brewis, Vice President Operations at Dodge Data & Analytics gave the presentation.  Cliff is a highly accomplished Vice President with a successful track record in sales management, operations, change management, process planning, implementation and public speaking. In over 30 years of management experience there has been a focus on driving continuous improvement, operating within budgets, meeting required objectives and implementing change to improve effectiveness and efficiencies.

    He gave a rather steady outlook for growth, at a pace of 3-5%.  Attached you can see the data from his presentation. 

    Dodge 2015 Outlook - ACI.pptx
  • 14 May 2014 10:54 AM | Anonymous

    When the American Concrete Institute develops a new Standard, part of the development process includes making the new document available for public review and comment. This is the opportunity for anyone effected by the standard to review the materials and submit their comments to the committee for discussion. 

    The draft standards listed below are being processed through ACI's ANSI-approved standardization procedure and are currently open for public discussion from May 1st to June 17th. You can view these documents along with instructions and comment forms by going to http://www.concrete.org/Publications/TechnicalDocuments/UpcomingStandards.aspx


    ACI 318 and 318.2

    Building Code Requirements for Structural Concrete and Commentary AND Code Requirements for Thin Shells and Commentary

    ACI 423.7

       Specification for Unbonded Single-Strand Tendon Materials


    Discussion should be emailed to Discussion@concrete.org using the comment form for the corresponding draft standard. The comment forms and draft standards are available on the Upcoming Standards Web page

    Due to the volume of comments received, all comments must be submitted via the Comment Form to be considered by the committee. Please type the document number in the subject line. Public  discussion and committee responses will be made available at a later time. The draft standard will become an official ACI standard after the discussion period closes and the committee responds to the discussion received.

     

  • 27 Jan 2014 3:44 PM | Anonymous
    The American Concrete Institute is pleased to unveil its new logo. This refreshed identity signifies the next step forward in the evolution of the ACI brand and serves as the foundation for consistent design and messaging across all ACI communications. In addition to the logo, the tagline "Always advancing" highlights the fact that everything the Institute does centers on advancing concrete knowledge, technology, construction, and quality, as well as collaboration and professional growth. The new logo was approved unanimously by ACI's Board of Direction, and is the first major update to the Institute's logo since 1964. Read about the new logo, its development, and history of ACI's logos in ACI President Anne Ellis' January Memo.


 

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