PHOTO: © BRANKO / ADOBE STOCK
DECEMBER 2023
GOOD VIBRATIONS HITTING THE RIGHT
FREQUENCY FOR YOUR MIX IN THIS ISSUE: 36 CCE Preview | 38 Concrete Products | 40 WOC Preview | 42 Demolition
The Worldwide Leader in Concrete Paving Technology
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APPLICATION PRACTICES
GOOD VIBRATIONS
Researching vibration energy transfers to help track better vibration field practices. BY PAUL JAWORSKI
PHOTOS COURTESY OF MINNICH MANUFACTURING
M
embers of the American Concrete Institute (ACI) are working to bring more understanding about the use of vibration energy to the industry to improve outcomes for contractors. At the just-concluded ACI Fall Convention, promising research was presented to the Consolidation Technical Committee that can be used to capture and gather data for the purpose of machine learning during the vibration of concrete pavements. Members of the committee have been busy for the past four years gathering and testing quality control methods to offer more predictable outcomes in vibrating various concrete mixtures across several construction applications. With ACI 309 Consolidation Guidance document being re-written, the members have been engaged in producing a new document that will offer contractors a better understanding of vibration energy and how to limit the amount of surface damage from over-vibration. Since the concrete industry is focused on carbon-neutral initiatives, which includes producing concrete mixtures that use Type 1L cement, the committee has stepped up the urgency to update its guidance document. Vibration research for the document has been concentrating on the challenges of placing pumpable mixtures without separating available mix water and a more advanced testing platform targeted at machine-learning methods in placing concrete pavement mixtures. The effort has been focused on construction case studies using controlled frequency vibration (CFV) that applies the same vibration energy to the concrete, and more importantly maintains a frequency, despite any concrete load changes. The method has led to specifications that set maximum allowable limits to vibration frequency in pavements to limit any concrete distresses from frequency over-vibration. New limits to vibration frequency will result in a maximum frequency for commercial applications, especially pumpables. In 2021, Iowa State University released a study of the effects
of vibration on mixtures by looking at vibration energy transfers to clinically verify what the field studies have been empirically telling us about frequency over-vibration: the quality of concrete surfaces is usually compromised with vibrator frequency. Iowa State researchers used a fixed frequency and output of force during vibration that can be tracked through the concrete. This revealed important factors that outline the behaviour of frequency and the material separation that it causes (see Chart on Page 34). The energy transfers reveal how to meet consolidation standards in concrete mixtures while limiting the issues that come with over-vibration of low-viscosity mixtures. In a sustainable model, vibration energy is the easiest piece of the puzzle to control. The researcher simply chooses a fixed vibrator frequency that matches the workability of concrete at pre-construction trials during mock-ups. In both pavements and pumpable mixtures, just the frequency control and reduction in frequencies has shown a marked improvement in limiting the damage that high frequency does to most concrete mixtures. Once the vibrator is set at a frequency, the control of vibration process turns to evaluating the variability challenges in the workability associated with concrete production. on-sitemag.com / 33
APPLICATION PRACTICES the committee that all slump values are not equal. Two different concrete mixtures can have the same slump value but may have arrived at that slump through different amounts of water-reducing agents. Although the samples are the exact same slump as indicated by the slump cone test, they react differently when vibration energy is introduced. Forced concrete bleed by frequency: The usual predictable This revelation allows for a water separation by vibrator frequency is illustrated. much better understanding of To set vibration frequency and move several conditions of over-vibration by towards machine learning, a method of vibrator frequency by evaluating vibration controls includes reading changes in energy against what the concrete resistance concrete workability and understanding how (dampening effect) before widespread to adjust vibration to those changes. material separation occurs. The ability to measure vibration energy Once you go past concrete’s threshold, in fresh concrete is paramount to limiting you begin to relocate water away from the the damage that is continually done by vibrating head to the surface of paveover-vibration in many concrete placement ments, or to the form surfaces in the case applications. For a century, the vibration of placing pumpable mixes. In concrete process has tried to match applied energy pavements, the paving machine will evenwith a slump cone test. The slump cone tually have vibration energy transfer sensors test is seldom used in measuring the that will aid in the machine learning of concrete workability of pavement applicaconcrete paving machines by tracking and tions, however. logging the vibration energy transfer data. The initial study of using vibration The information from the transfer data will energy transfers on mixtures showed that be sent to the paver’s network controller to the slump cone test was also not an indicaallow more controls on the paving process. tor for any commercial concrete mixtures. The paver already uses a vibration In the Iowa State study, energy transfers monitoring system to control a vibrator showed that the measure of static yield in frequency range, but the learning with the slump cone test did not represent what energy transfers can look at the effects happens when vibration energy is applied of static head, change in workability and to the concrete. A better view of vibration’s frequency adjustments to the paver’s effects comes with capturing the dynamic forward travel speed. yield of concrete through analyzing vibraTracking energy transfers can also be tion energy transfers. a big help in analyzing concrete samples The ability to show dynamic yield from the laboratory, batching, transport values through energy transfers has told and the condition of the concrete workabil-
Forced concrete bleed by frequency: The usual predictable water separation by vibrator frequency is illustrated.
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ity as it enters that paver prior to vibration. How does all this help contractors place pumpable mixtures? The research, case studies and field effort to find better vibration solutions through the development of quality control tools and methods to meet the always-changing materials in mix designs, is a matter of developing tools for our biggest priority—constructability. The committee has incorporated guidance maximum limits when vibrating pumpable and near flowable mixtures above the measured five-inch slump value. The most adopted frequency during field trials has been the 8,000 vpm range to immediately bring down the amount of water separation. In the new Consolidation Guidance Document, methods will be outlined for determining a compatible frequency for the trial mixture at mock-ups. Choosing a frequency that offers the least disturbance for the amounts of available water in the mixture is the first step, and The “Quake” has been developed by Oklais very helpful in homa State University controlling concrete to help understand the surface issues. behavior of vibration Vibration has energy. always been misunderstood because research and science has not been exposed to users, but controls are important to sustainable concrete placement practices. The best way to control concrete issues is to accurately measure fixed frequency vibration and variability in concrete production. With the eight different ongoing research studies involving vibration’s effects on concrete, field controls through analyzing energy transfers will soon become reality.
Paul Jaworski is the product manager at Minnich Manufacturing, Inc. He has more than 40 years of experience in concrete vibration and consolidation.
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CCE 2024
CANADIAN CONCRETE EXPO SET FOR FEBRUARY
Sixth annual CCE returns to the GTA this February with demos, training, networking, and more.
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and better value for attendees.” CCE provides an environment to source new suppliers, reconnect with industry contacts, get hands-on with the latest equipment, and take advantage of exclusive show offers. For those looking to expand their industry knowledge or skills, educational sessions are available to help maintain and develop a greater skillset in Canada’s diverse and evolving concrete construction industry. The exposition will be located at the International Centre in Mississauga, only five minutes from Toronto’s Pearson International Airport. Registration for CCE 2024 is now open. Register in advance to save 50 per cent on the admission fees. For more information, or to register, visit canadianconcreteexpo.com.
PHOTO BY ON-SITE STAFF
C
anada’s national trade show dedicated to the concrete, construction and aggregates industries, the Canadian Concrete Expo (CCE) will return for its sixth year on February 14 and 15, 2024. Set to take place at the International Centre in Mississauga, Ont., this year’s event has grown once again and will feature a 300,000 square foot exhibition floor with more than 350 national and international exhibitors, educational seminars, and product demonstrations. CANADIAN “If people have not been CONCRETE EXPO to the show, since its early years, we’ve grown 350 per February 14-15, 2024 cent from the first year that we did the show,” says CCE International Centre, president Stuart Galloway. 6900 Airport Rd., “The sheer volume of exhibMississauga, Ont. itors, and the product, service and equipment selection, has grown exponentially. There’s so believe the quality of our much more to see.” conference sessions is the best Expected to attract in excess of 8,000 it’s ever been.” industry attendees, the expo has a slate Another major aspect of the show that of more than 40 conference sessions, live is expected to attract attention of attendees demonstrations and stage presentations that will be the large equipment demonstrations. will provide attendees the chance to experiThese live indoor pours will showcase the ence the latest technology and equipment, newest innovations the industry has to offer, and access key industry insights. plus innovations in decking, forming, equip“We know that for people to make the ment, and much more. trek, let’s say from Eastern or Western “We brought back our large equipment Canada, and even the Southern or Northern demos, which are indoor. We’ve got live United States, we’ve got to provide some concrete pours and are bringing in larger education for them as well,” says Galloway. equipment that we can demo inside, plus “They’re looking for a multi-multifaceted multiple product presentations on our main event that not only provides them exhibstage and Hall 2,” says Galloway. “We’re itors, but where they can get education really trying to focus on growth in those and networking at the same time. So, areas as well to provide a better experience we’ve really expanded our sessions, and we
PRODUCTS
CONCRETE PRODUCT SHOWCASE BREAKER HAMMER Launching this month, the DeWalt 60V Cordless HEX Breaker Hammer Kit is a 41-pound cordless breaker hammer that can deliver up to 41 Joules of impact energy. It works with 1-1/8” hex-shank bits and is designed for such tasks as chipping mid-to-lower wall and flooring, powered digging, channel creation, and slab demolition. The breaker hammer delivers up to 1,080 BPM and has a chipping range of 1 to 8 inches. Additional features include wireless tool control, compatibility to automatically activated DeWalt vacuums and dust collectors, and built-in SHOCKS anti-vibration control.
Adrian Steel ladder racks are designed to make loading and unloading ladders easier and more ergonomic, but their most important function is helping you make it safely home at the end of each day.
OnSite_AdrianSteel_Oct23.indd 1
Milwaukee Tool’s M18 FUEL Concrete Pencil Vibrator offers a cordless compact solution when working in confined and restricted spaces. Essential to the concrete consolidation process, the pencil vibrator generates up to a 1.8 peak HP, using a Powerstate brushless motor to deliver up to 12,500 vibrations per minute. It is available in four- and eight-foot lengths, has a one-inch square head, and features a variable-speed trigger.
REMOTE-CONTROLLED DEMOLITION MACHINE Designed for heavy-duty, difficult-to-access projects and applications, the Brokk 200 looks to deliver the power of a 3-ton machine in a 2-ton package. The 27.5-kilowatt machine operates tools with requirements typical of one weight class above. When paired with the manufacturer’s BHB 305 breaker, the unit’s hitting power is increased by 40 per cent, delivering 450 foot-pounds (610 joules) with each blow of the 650-pound (295-kilogram) hydraulic breaker.
ProLiftTM elevates safety by lifting ladders with unique, patent-pending mechanical advantages and dampers. Ladders can be raised and lowered effortlessly. Requiring up to 50% less effort from you to do the job, ProLiftTM helps reduce back and shoulder injuries. With Adrian Steel, ladders stay put and you stay safe, it’s as simple as that. Learn more about ProLiftTM and our ProfileTM rack system at adriansteel.com
38 / DECEMBER 2023
BATTERY-POWERED PENCIL VIBRATOR
2023-09-27 1:50 PM
COMBINATION CONCRETE SLIPFORM PAVER
CEMENT MIXER VOCATIONAL TRUCK Western Star’s 47X twinsteer offers a factory-installed 72” set-back axle spacing and a 60” set-forward axle spacing prep aimed at providing durability, weight savings and ease of upfit. Designed to support Truck Equipment Manufacturers (TEMs), it provides essential components, including an additional dressed second front axle with wheels and tires, ample cab clearance, and a strategically positioned Aftertreatment System (ATS) mount, to allow ease of installation of their twin-steer front suspension.
Gomaco’s GP460 combination concrete slipform paver and placer/spreader will accommodate widths up to 50 feet (15.2 m) wide as a placer/spreader with a 60-inch (1524 mm) belt and will pave widths up to 40 feet (12.2 m) wide as a concrete slipform paver. The machine is built on the framework of the company’s two-track GP4 slipform paver and is powered by a Caterpillar C7.1 turbocharged diesel engine.
SOLID BODY HYDRAULIC BREAKERS A reliable choice for demolishing light concrete structures and asphalt pavements, both outdoors and indoors, Epiroc’s solid body hydraulic breakers offer blow frequencies from 550 up to 2,300 blows per minute and are available in nine models with service weights ranging from 55 kg to 1,060 kg. The company’s SB 152-SB 1102 come with integrated water nozzles as an option for dust suppression. With these nozzles, located in the front of the hydraulic breaker, dust is suppressed where it is created.
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on-sitemag.com / 39 2023-11-28 10:08 AM
WOC 2024
CELEBRATING 50 YEARS OF WORLD OF CONCRETE
WORLD OF CONCRETE 2024 Las Vegas Convention Center Jan. 23-25, 2024
W
orld of Concrete (WOC) is gearing up for its much anticipated 50th edition at the Las Vegas Convention Center (LVCC). Presented by Informa Markets, the annual event brings together the newest products, leading-industry suppliers, resources, and valuable education necessary for concrete and masonry professionals. In 2023, WOC drew more than 48,000 registered professionals, with bustling foot traffic throughout the show, high engagement with the comprehensive educational offerings, and overall enthusiasm from participants, underscoring the industry’s critical need for in-person connections. WOC 2024 will feature more than 1,200 exhibitors spanning more than 700,000 sq. ft. of indoor and outdoor exhibit and event space, as well as a world-class education program. This year’s show runs from January 23 to 25, with education sessions available starting on the 22nd.
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The show is set to take place in the North, Central and South Halls of the Las Vegas Convention Center, as well as in the Silver and Bronze Lots for outdoor exhibits and events. Central Hall is the place to check out material handling products, from trucks, excavators, paving equipment and more for material delivery, distribution, concrete placement, and earth moving, along with commercial construction concrete and masonry tools, and the ever-popular Work Truck LIVE! Work Truck LIVE! highlights innovations in the design and configuration of work trucks as well as innovative accessories that will help contractors increase safety and productivity. Concrete producers, and contractors looking for information about construction technology, precast products, concrete masonry and concrete reinforcement will be well served by the demonstrations, products and services on display in the North Hall. In addition to all things masonry, the South Hall in the LVCC will also feature concrete repair and demolition, and surface and decorative products, including the latest in surface preparation equipment, scarifying, grinding, sawing equipment, sealants, joint fillers, coatings, and cleaning solutions. The outdoor areas, in the Silver Lot and Bronze Lot, will feature live demos and heavy equipment, as well as championships, skills challenges and demos. Starting a day before the exhibits open, the 2024 World of Concrete Education Program will offer a variety of in-depth learning options for concrete and masonry professionals covering such topics as technical applications, business best practices, project management, and safety-relevant topics for every skill level from beginner to experienced. For more information about the show, and to register, visit www.worldofconcrete.com.
PHOTOS COURTESY OF WOC/INFORMA MARKETS
International event for the concrete and masonry industries brings the industry to Las Vegas this January.
E X H I B I T S : J A N U A RY 2 3 - 2 5 , 2 0 2 4 E D U C AT I O N : J A N U A R Y 2 2 - 2 5 LAS VEGAS CONVENTION CENTER
WHERE
LEGENDS ARE MADE
As the industry’s No. 1 authority, we’ve stayed true to our mission to support the needs of concrete and masonry professionals. Today, we’re working just as hard to deliver opportunities and strategic connections as we did on day one. Join us to see, touch and test state-of-the-art solutions that drive informed decisions and put your business on solid ground for the year ahead.
B U I L D A L E G A C Y O F S U C C E S S. LEARN MORE ABOUT WOC
VIEW INTERNATIONAL EVENTS
REGISTER NOW at worldofconcrete.com
DEMOLITION
FITTING THE BIT TO THE JOB Maximize concrete demolition efficiency by using the right bit. BY JEFF KEELING
S
electing the right tool for the job is the key to minimizing effort and maximizing efficiency in concrete demolition applications. Working with a remote-controlled demolition machine is one way to take safety and productivity to a next level, but tool selection is a major factor in getting the most from your machines. The wrong tool selection, on the other hand, can slow down productivity or leave behind unsatisfactory results. Knowing the difference leads to huge advantages in an increasingly competitive field. Here are some tips for selecting the right tool to maximize breaking potential.
MOIL POINT The moil point tool is the most common bit found on jobsites. The pencil-tip design focuses the entire force of the hammer and carrier in a 1/4-inch point, which limits vibrations, making it perfect for indoor applications and other situations where vibrations are unacceptable. Good precision and control make it ideal for breaking hard concrete reinforced with rebar in applications such as walls, footings, floors, foundations or machine bases. However, it doesn’t provide the level of precision necessary for fine detail work. The cone-shaped head can also get stuck as dust may lodge it in place. Avoid this by paying special attention to the running time of the hammer. Don’t run for more than 20 seconds in the same spot without noticeable results. The moil point has several variations
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Having bit options on hand increases versatility and efficiency.
The moil point offers a good level of control.
that offer further efficiency in certain situations. A pyramidal moil point, also known as a “nail head,” provides minor torsion and a wedge effect in four directions, making it a better dividing tool. The shape also keeps the nail head from getting stuck as much. Operators often rely on the cone-shaped moil rather than a tool more appropriate for the job. Carefully consider all aspects of the job before automatically selecting this tool.
area of impact when breaking slab concrete, making it ideal for floors, steel beams encased in concrete, recycling and certain roadwork applications. What it lacks in precision, it makes up for in destructive power. Distributing energy across the entire face covers a significantly larger surface area than pointed tools and greatly increases overall efficiency. This tool produces heavy vibrations, which limits its use in applications like indoor and top-down demolition, and some road and bridge repair.
CHISEL A chisel tool provides strong torsion and good penetration, resulting in the best splitting action. It’s ideal for trimming applications, including floors, walls and foundations, as well as demolishing reinforced columns, supports and blocks. Select a chisel for cleaning up between rebar on the edge of a slab to ensure an ideal bonding surface for pouring concrete. The chisel also offers the best precision for fine detail work.
BLUNT The blunt tool’s flat face delivers a wider
SLAB BUSTER For maximum destructive power, the slab buster, or “elephant foot,” is the go-to tool. Shaped like a bell, it distributes energy over a surface area three times its size, doubling production of both slab and on-grade demolition. However, vibrations and very little precision can limit applications.
Jeff Keeling is the vice-president of sales and marketing for Brokk Inc.
A WIRTGEN GROUP COMPANY
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SP 25(i): Whether for monolithic profiles or concrete pavements, the Slipform Paver SP 25(i) from WIRTGEN stands for versatility and cost-effectiveness. The mould can be positioned on either side of the machine, inside or beyond the chassis. Concrete slabs up to 3.50 m wide can be paved in inset application. Take advantage of innovative solutions from the technology leader. www.wirtgen.com
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