World of Concrete 2007
January 22-26 (Seminars)
January 23-26 (Exhibits)
Las Vegas, Nevada, USA
Free admission (up to $60 savings) and discounts on seminars (up to $40 savings per seminar), courtesy of the American Concrete Institute.
Spend a day or the week at the industry’s largest annual international event, and you’ll be on the road to a stronger, more profitable, and competitive business. The hottest trends, materials, equipment, techniques, and information you need all under one roof. If you work with concrete in any way, shape, color, or form, this is the year’s must-attend event. To receive free admission and discounts on seminars courtesy of the American Concrete Institute, click here to register online or mention code “A21.”
World of Concrete 2007 will be the industry’s largest international annual event, featuring more than 800,000 net square feet of innovative products, tools, and technology to help you succeed. Additional highlights include:
- Hands-on action under actual jobsite conditions letting you see for yourself how new products and equipment can benefit your operation;
- More than 1,700 industry suppliers from all over the world will be available to answer questions, demonstrate products, and conduct business with you; and
- The most respected seminar program in the industry offering training and certification programs in several targeted tracks, including training for ACI’s Concrete Flatwork Finisher and Tilt-Up Supervisor certification programs.
More information
If you’d prefer to register directly at www.worldofconcrete.com, from www.concrete.org, or if you experience any problems or are prompted, please use code “A21″ to receive your gift admission and seminar savings. Alternatively, you may download a printable version of the World of Concrete registration form.
Some dates to be determined
January 9, 2007
Moisture in Concrete Floors
Ralph Godfrey
The Handlery Hotel & Resort
February 13, 2007
Pervious Concrete
Tom Tietz
March 13, 2007
Concrete Restoration With Epoxy
Injection – A. B. Bortolin, Sika
April 10, 2007
Architectural Concrete
T.B. Penick & Sons
April 12-15, 2007
Western Regional Conference
University of California – SD Host
San Diego
May 4, 2007
ACI Annual Awards Dinner
Sycuan Resort – El Cajon
May 17, 2007
Design and Construction of Concrete Parking Structures – Seminar
San Diego
June 12, 2007
Troubleshooting Concrete Construction – Seminar
San Diego
ACI San Diego Chapter
Lee Hubbard Concrete Constructor Award
This award honors either a construction company or individual who has advanced the art of concrete construction. There are no specific criteria. However, credit will be given for membership in ACI. Submit narrative and supportive data or photos for consideration of receiving the award to ACI, San Diego Chapter, P.O. Box 12649, El Cajon CA 92022.
November 14, 2006 – Solving Problems in Concrete Construction Non-Destructively
This program is designed to introduce the local concrete industry to the state of the art non-destructive testing methods available for evaluating concrete.
Non-destructive testing has saved million of dollars worth of demolition and replacement of questionable concrete. Non-destructive testing has expedited construction schedules and been responsible for millions of dollars worth of early completion bonuses. Come to this ACI seminar and find out how. After the seminar there will be hands-on demonstrations of state of the art non-destructive testing equipment including
- Low frequency ultrasonic pulse velocity testing
- Impact Echo Testing
- Penetrating Radar
The seminar will compare various types of non-destructive testing with common destructive methods such as coring and selective demolition. During the hands-on demonstrations we will expose much of the mystery and “black box” technology that surrounds the non-destructive testing field.
The capabilities and limitation of the various systems will be discussed. You will no longer have to take non-destructive testing results on faith; you will be able to understand the applicability and the methods used.
For more information or to order in of the following publications call 248.848.3800.
117-06: Specifications for Tolerances for Concrete Construction and Materials and Commentary
This specification provides standard tolerances for concrete construction. This document is intended to be used as the reference document for establishing tolerances for concrete construction by specification writers and ACI committees writing standards. The commentary on the Specifications for Tolerances for Concrete Construction and Materials is intended to be used with ACI 117 for clarity of interpretation and insight into the intent of the committee regarding the application of the tolerances set forth therein. $75.50 (ACI members $46.00); Order Code 11706.EM.
SP-237 CD-ROM: Finite Element Analysis of Reinforced Concrete Structures
This CD-ROM is a collection of 19 papers presented at a workshop sponsored by Joint ACI-ASCE Committee 447, Finite Element Analysis of Reinforced Concrete Structures, and JCI Committee 016SP, in Maui, Hawaii, USA, in November 2003. A broad range of topics was addressed, including the creation of new experimental data sets for use in developing, calibrating, and validating models; the development and validation of plain, reinforced, and fiber-reinforced concrete constitutive models; new approaches to simulating the response of reinforced concrete continua; new element formations to enable improved simulation of component response; and new computational techniques. $70.50 (ACI members $43.00); Order Code SP237CD.EM
SP-238: International Symposium on Confined Concrete
This Symposium Publication contains 28 papers that were presented at an International Symposium on Confined Concrete held at Hunan University, Changsha, China, in June 2004. Topics include performance-based design and seismic analysis, confined concrete models, finite element modeling, confined concrete in steel and concrete composites, and FRP confined concrete. $93.50 (ACI members $56.00); Order Code SP238.EM.
SP-239: Eighth CANMET/ACI International Conference on Superplasticizers and Other Chemical Admixtures in Concrete
This Symposium Publication includes 36 papers selected from a conference that took place in Sorrento, Italy, in October 2006. Topics include cementitious systems, ultra-high-strength
concrete, artificial superplasticized aggregate, mortars, and self-compacting concrete. Papers include:
- Development of New Superplasticizers Providing Ultimate Workability;
- Artificial Superplasticized Aggregates for Decorative Applications;
- Effectiveness of Commercial Corrosion Inhibitors for Reinforced Concrete;
- Interaction between Cements and Superplasticizers;
- Effectiveness of Superplasticizers Incorporating Shrinkage-Reducing Admixture in Recycled-Aggregate Concrete; and
- 31 more papers on superplasticizers and other chemical admixtures in concrete
$111.50 (ACI members $69.00); Order Code SP239.EM
SP-240 CD-ROM: Performance-Based Design of Concrete Building for Wind Loads
This CD-ROM contains six papers that were presented at the technical session on Performance Based Design for Wind Loads, held San Francisco, CA, in Fall 2004. Topics include an overview of performance-based design, the nature of wind loading and wind tunnel testing, structural modeling assumptions, components of lateral deformations in buildings, and the types of concrete structural systems for wind loading. $59.50 (ACI members $36.00); Order Code SP240CD.EM.
302.2R-06: Guide for Concrete Slabs that Receive Moisture-Sensitive Flooring Materials
This guide contains materials, design, and construction recommendations for concrete slabs-on-ground and suspended slabs that are to receive moisture-sensitive flooring materials. These flooring materials include sheet rubber, epoxy coatings, vinyl composition tile, sheet vinyl, carpet, athletic flooring, laminates, and hardwood. Chapters 1 through 8 provide an understanding of concrete moisture behavior and drying, and show how recommended construction practices can contribute to successful performance of floor covering materials. This background provides a basis for the recommendations in Chapter 9 to improve performance of floor covering materials in contact with concrete moisture and alkalinity. $65.50 (ACI members $39.00); Order Code 302206.EM.
306R-88: Cold Weather Concreting
This document provides the general requirements for producing satisfactory concrete during cold weather and methods for satisfying these requirements. In particular, this document discusses recommended temperature of concrete, temperature records, temperature of materials, preparations prior to placement, duration of protection period, methods for determining in-place strength, form removal, protective insulating covers, heated enclosures, curing methods, and accelerating admixtures. References are included that provide supplementary data on the effects of curing temperature on concrete strength. $37.50 (ACI members $23.00)
Order Code: 30688.EM
Jobsite Water Addition
By Ken Parks and Jim Turici, CEMEX USA
One of the biggest challenges the concrete industry faces today is the jobsite addition of water. The National Ready Mixed Concrete Association explains this challenge as:
“Jobsite addition of water is the addition of water to ready mixed concrete in a truck mixer after arrival at the location of the concrete placement. Such tempering of concrete may be done with a portion of the design mixing water which was held back during the initial mixing, or with water in excess of the design mixing water, at the request of the purchaser.”
The concrete supplier designs and supplies the concrete according to the project or industry specifications to perform as intended. When water is added in excess of the design water/cementitious ratio (w/cm); the water will affect the concrete properties and performance.
What effects does the water have on the properties and performance?
One gallon of water (over the designed water cementitious ratio) added to one cubic yard of concrete will:
- Reduce the compressive strength by as much as 200-psi,
- Eliminate the effect of approximately 25 lbs of cement,
- Increase the slump approximately one inch,
- Increase the shrinkage potential by 10%,
- Decrease the freeze-thaw resistance by as much as 20%.
There are also a multitude of concrete surface defects that are often caused by the addition of extra water into the mix. These surface defects include but are not limited to: drying shrinkage cracking, crazing, scaling, mortar flaking, dusting, discoloration and delamination. With proper curing techniques some of these surface defects may be minimized but there is no guarantee.
What is the proper way to add water?
The concrete should have an adequate amount of mixing (typically 70 to 100 revolutions at mixing speed in a revolving drum truck mixer from the initial introduction of water to the cement) in order to be thoroughly mixed for evaluation of slump. ASTM C 94, Standard Specification for Ready Mixed Concrete permits one addition of water at the job site until the desired slump is achieved provided that the maximum w/cm is not exceeded and this re-tempering water is added before any concrete has been discharged. If water is added after a portion of the load is discharged, it is not practically possible to determine the w/cm of the re-tempered mixture in the truck.
After addition of the water, the concrete should receive at least 30 drum revolutions at mixing speed to ensure uniformity. The maximum number of drum revolutions for the entire load should not exceed 300. Also the device for the measurement of added water should be capable of adding the desired quantity of water within the accuracy of 1% of the required total mixing water.
If water cannot be added, what should we look at?
There are times when the jobsite specifications will not allow any further addition of water to the concrete mix. There are many ways to help enhance concrete workability.
Aggregates play an important role in the overall performance of the concrete mix. According to the Portland Cement Association, “Design and Control of Concrete Mixtures”, the grading and maximum size of aggregate proportions affect relative aggregate proportions as well as cement and water requirements, workability, pumpability, economy, porosity, shrinkage, and durability of concrete.
Chemical admixtures are another way to enhance the workability of the concrete mix. Superplasticizers and water reducers may be used to increase the slump while providing better cohesiveness, water retention, strength and improved placement properties. Be aware that adding water to a mix that already contains chemical admixtures may alter the properties of the mix. These property changes include but are not limited to inconsistent setting, changes in air contents, and excessive slump loss. Please contact your local admixture supplier and follow the suggested manufacturers’ dosage rate guidelines when using chemical admixtures.
Moving forward…
Concrete is produced to meet the specifications supplied to the ready mixed concrete company from the end user. When water is added at the jobsite over the specified maximum slump and water cementitious ratio, it has a detrimental effect on the properties and performance of the concrete as specified. To decrease the chance of having this occur, a pre-construction meeting or conversation should be held to discuss who has authorization to add water and how this addition is documented. During the discussion, chemical admixture options should also be addressed.
If jobsite water additions are allowed to occur and the concrete is to be sampled for quality control or quality assurance testing, it is imperative that the sample be properly obtained after all water additions have been added to the batch.
For further information on jobsite addition of water please contact the American Concrete Institute, the Portland Cement Association or the National Ready Mixed Concrete Association.