As an editor, I go to a lot of conventions—just this year alone, I’ll head to eight shows before the year is up between my role as editor of Construction & Demolition Recycling and our sister publication, Waste Today.
These shows give me an opportunity to get out from behind my desk to learn about what’s going on in the industry and to hear what hot-button issues people in the industry are talking about.
While this is invaluable, I’ve found that most shows follow the same basic format that has remained virtually unchanged for decades. This usually includes a smattering of educational sessions and networking events interspersed with opportunities to visit the exhibitor floor to check out what new products and services the attending vendors have to offer attendees.
Along with the stress balls, phone chargers, keychains and other tchotchkes that adorn tables throughout the exhibitor hall, you’re likely to find vendors’ booths piled high with stacks of press information and brochures meant for public consumption.
But with everyone equipped with a smartphone and a 24-hour-a-day internet connection, the reason for attending a convention has less to do with accessing basic company or product information as it does getting insight into something more valuable that can’t be garnered from behind a screen.
That’s why this year’s Demolition Austin show put on by the National Demolition Association (NDA), Washington, Feb. 22-24 was such a breath of fresh air. As part of its inaugural Live Demolition event, the NDA procured a space off-site for contractors to be able to see, learn about and operate some of the latest construction and demolition heavy equipment on the market.
From shears and grapples to crushers and excavators, the equipment presented an interactive, hands-on opportunity for attendees to engage with vendors and get something out of the experience beyond what reading product specs in the confines of a booth allows.
People who spend significant money and travel long distances to attend a show aren’t there to read information that can be readily found on a company’s website. Today’s professionals are looking for solutions that can help make their businesses run more effectively and profitably.
That begins with starting a very different conversation, one where the pain points of the attendee are front and center.
The convention isn’t going away as a means of introducing people to new products and ideas. It’s how these products and ideas are packaged that warrants a closer inspection.
A lot has changed in how business is conducted over the last few decades—isn’t it time that the convention experience changed along with it?
Check out “Demo comes alive” in this issue to learn more about the Live Demolition event and how in-person communication is becoming more vital for contractors when it comes to equipment purchasing.
Scrap Iron: Reported United States aggregated spot market prices per gross ton shown for each commodity are based on all Management Science Associates’ (MSA) Raw Material Data Aggregation Service (RMDAS) participants’ actual order data submitted to and processed by MSA as of the 20th of each respective “buy month,” rounded to the whole integer. A map of RMDAS regions is available at http://rmdas.msa.com, as is a further explanation of RMDAS methodology and an accompanying disclaimer.
No. 1 HMS defined as prepared obsolete scrap, 5 feet long and under. Additional pricing information on each grade can be found at www.RecyclingToday.com.
Copper - LME Pricing: Source: London Metal Exchange, www.lme.com
Aluminum - LME Pricing: Source: London Metal Exchange, www.lme.com
Stone and Aggregate Pricing: *Index is based on 1982 average price as 100 Source: U.S. Bureau of Labor Statistics
Wood Scrap: Source: North American Wood Fiber Review; Detailed pricing and analysis for California and other U.S. regions is available by subscription at www.woodprices.com.
Crushing it
Features - Operations Focus // Recycled Aggregate Sizing
Cherry Cos.’ 12 concrete crushing and stabilized material sites grow the company’s footprint and keep its product costs down.
Demolition and construction projects can produce immense amounts of debris in the form of concrete, metal, shingles and wood. The actions taken when disposing of this debris determine whether it will wind up at a landfill or recycling center. Cherry Cos., Houston, has forged its path as a demolition contractor and recycling firm.
Cherry Cos. has been in business for more than 65 years and recycles more than two million tons of concrete and asphalt and thousands of tons of steel every year. The company produces more than two million tons of stabilized material annually for the greater Houston area. The company also specializes in structural removal ranging from highways and bridges to industrial plants, commercial buildings and residences.
With such a large quantity of material to process, Cherry has opened 12 concrete crushing and stabilized material locations across the area, including in Houston, Spring, Rosharon, Richmond, Cypress, Manvel, Hitchcock and Fresno. The recycled crushed concrete is used primarily in road and highway projects, and the stabilized material ends up in parking lots, underground utilities, pipeline support and storm sewers, among other uses.
“Location makes a huge difference in accepting, processing and transporting products,” Joe Rizzo, vice president of business development, Cherry Cos., says. “Our stabilized products have a shelf life and need to be delivered quickly. Also, the cost of transportation and distances the trucks travel add to the price of the product, so having facilities strategically located in and around the greater Houston area allows us to be competitive with our pricing.”
Keeping down costs
Cherry Cos. opened its first crushing yard in 1996. According to the company, some of the 12 facilities are dedicated to crushing and recycling concrete, others are used to produce stabilized material and some process both. The sites that recycle concrete produce 2,000 tons of crushed concrete per day, while the sites that stabilize produce 7,000 tons per day. Crushers, screens, pugmills, loaders and excavators are used at all sites.
The types of stabilized materials produced include portland cement, water, and either sand, recycled aggregate or natural aggregate. Once mixed in the pugmill, the material has a shelf life of approximately four hours before it hardens. To extend that shelf life, Cherry Cos. deposits the stabilized material into trucks that transport the material. The company says stabilized sand is the most popular stabilized material it produces by volume.
Concrete crushing sites receive material from Cherry’s own demolition projects and from other contractors. As an example, Cherry crews recently worked on a bridge demolition project where the concrete and rebar were processed. The bridge was torn down, and the debris was broken up on-site with hammers. It was then loaded into the trucks that transported it to one of its nearby crushing facilities. There, the concrete was further reduced in size to fit in the crusher, sorted and then crushed.
The company says the recycled concrete goes through the line where it is sorted mechanically and by hand, then crushed and screened to produce a variety of different sized products, such as 3/8-inch-minus fines, 1- to 1.5-inch flex base, 1- to 1.5-inch screened rock, bull rock, blanket stone, grades 1 and 2 rip rap, recycled asphalt pavement and asphalt shingles.
For the most part, the company says, each concrete crushing site uses the same processing line. Six sites have a stationary crusher and three satellite sites stockpile concrete and bring a portable crusher to the site once there is enough to process.
Weighing out the benefits
While having 12 locations helps facilitate production for Cherry Cos., there are some challenges, such as maintaining a full staff at each site.
“Having enough employees to be there at all these different sites can sometimes be a challenge.” Rizzo says. “We have over 300 full-time employees and continue to add as Cherry Cos. expands its footprint and opens additional recycling concrete and stabilized material facilities in the greater Houston area.”
With the company’s number of employees and large scope of operations, comprehensive oversight is critical for facilitating production. Cherry says having a maintenance manager and production manager oversee and ensure the safety of each facility helps streamline production and maintain quality control at each site.
“‘Safety first’ is our motto, and we want to make sure everything is done correctly,” Rizzo says.
Although managing a dozen locations can be complex, according to the company, it allows Cherry Cos. to better meet its customers’ needs. In addition to helping mitigate the limited shelf life of its products, Cherry says the 12 sites allow the company to better reach customers and contractors, which decreases the cost and time needed for transportation. This allows the company to maintain a fair price for its products.
“We can reach just about anybody in the greater Houston area,” Rizzo says. “We have access to our own fleet of trucks, we have the ability to get to you wherever you are in a timely manner and, because of that, we can keep our products’ costs down.”
The author is the assistant editor for Construction & Demolition Recycling and can be contacted at hcrisan@gie.net.
Implosion inc.
Features - Explosive Demolition
Explosive demolition isn’t for every project or contractor. Two implosion specialists discuss what goes into handling these high-profile jobs.
High-profile implosion jobs may get a lot of press when it comes to demolition, but the truth is that less than 1 percent of all demolition work stems from these types of projects. Behind the scenes, tackling explosive demolition requires intense preparation, caution and a high-degree of expertise.
Construction & Demolition Recycling (CDR) talked with two of the industry’s leaders in implosion—Mark Loizeaux, president of Phoenix, Maryland-based Controlled Demolition Inc. (CDI), and Mark St. Cyr, safety manager at Detroit-based Adamo Group Inc.—to discuss what goes into a typical implosion job and what it takes to get the job done right.
CDR: What are the typical steps you undertake in between winning an implosion job and the job’s completion?
Mark St. Cyr (MSC): Upon being awarded the job, we work to firm up the schedule for the upcoming implosion. Oftentimes, there is demolition work that proceeds the implosion, so we make certain to keep the scheduled date for the implosion as close as we can to what the original plan was going into the job. We make certain the required licensing is in place for the state the work is being performed in. We develop an implosion plan and procedure to explain the exact plans of our scoped work, and we work closely with governmental agencies in getting the necessary approvals for the explosives to be brought on-site. Special security measures are then put in place while the explosives are on-site. We work closely with existing community organizations such as fire, police, emergency, utility companies and any other agency who may have input into the work or be affected by the work. We attempt to choose a day which is the least obtrusive to the area. Once the date for the implosion is set, we work with local agencies to make certain the community is well aware of the hindrances and potential delays it may experience due to road closures or other impedances due to the implosion. Following the implosion, we perform a thorough inspection of the site to assure the implosion event went as planned.
Upon a successful inspection, the area is released for personnel to enter again and the community or local site restrictions and hindrances put in place are removed to allow for normal operations.
CDR: What types of equipment are needed for a typical project?
Mark Loizeaux (ML): Generally, much of the same equipment used for strip-out operations prior to conventional demolition of a structure will be needed to prepare suitable structures for explosive demolition. This would involve small excavators, skid steer loaders and equipment with hydraulic hammers (for reinforced concrete structures). Larger demolition equipment might be needed to remove low-rise structures surrounding that high-rise structure to be felled. Generally speaking, any demolition contractor would have the equipment needed to prepare most structures for implosion.
MSC: For the typical implosion, there are various types of drilling equipment used. If setting the charges in concrete structures, there are drilling machines used. There is heavy equipment drilling used for extensive drilling, and manual drilling equipment used for tough access or minimal drilling requirements. Special protective barriers for the charges are almost always used to prevent the explosive charges from sending debris to a large area. If setting the charges in steel support structures, we use special torch-cutting techniques. The cutting techniques require propane and oxygen torches with precision cuts being done on the steel beams, columns, rebar or any other steel having charges set in place. Special vehicles with special licensing are required to transport the explosives.
CDR: What are the personnel requirements for a typical project?
ML: The key to a successful project is having someone with a structural engineering background who will fully understand the nature and condition of the structure. That engineer should be comfortable not only with the condition of structures in their static state, but also under loads which the structure was designed to withstand, such as live loads from operations, wind load and seismic loading if the structure is within an active seismic zone. It is helpful if that structural engineer also has a basic understanding of explosives operations and explosives products. Ideally, a blaster with an engineering background is best suited for design of implosions.
Once the structure has been analyzed and the extent of safe pre-implosion modifications has been defined, a project superintendent with adequate structural understanding of the structure and the modifications to be made is necessary to lay out the preparations and structural modifications, whether they are to be performed by the blasting contractor themselves or the main contractor under the direction and guidance of the blasting subcontractor. In all cases, the blasting subcontractor should be required to formally “approve” the modifications to be made and accept them once they have been made per the blasting contractor’s design.
The third phase requires a competent blaster with experience in handling the type of explosives needed for that specific project under the site circumstances in regards to remaining adjacent above- and below-grade improvements.
MSC: There are many personnel requirements to support an implosion. There are defined special licensing requirements for the personnel handling the explosives. There are special laborer burner skills required to be able to cut the steel in preparation for the charges being set. There are special equipment operator requirements for selective demolition to support the implosion, as well as special operator skills to use the equipment drills for explosives. We have a full team of personnel in place the day of the implosion working closely with the police and other agencies to make certain the site is clear.
CDR: What are some of the biggest issues you have to guard against?
MSC: The explosives not all being detonated as planned is the most important item we plan for. To alleviate this risk, we often use redundant wiring of each charge to add a high degree of certainty that the charges will go off as planned. As mentioned previously, the area is scoured following the implosion, and one of the most important tasks is the review of the area to assure all explosives have detonated as planned. A structure not falling exactly as planned is another item we prepare for. We also create an exclusion zone for every implosion. We post personnel on the perimeter to assure this area is clear. Lastly, the induced vibration can be a very important factor if we have surrounding buildings near the implosion zone, so we have to take precautions. We perform extensive vibration monitoring during the implosion to prove we did not exceed specific decibel levels for the implosion event.
ML: There are several things: 1. Making an adequate investigation to determine whether or not a structure can be prepared and safely imploded. Once that determination is made, you decide whether it should be imploded for commercial or other reasons. 2. Understanding the live loads which could be imposed upon a structure in its prepared state when it is most susceptible to premature failure. This has to be communicated to everyone who will operate in the vicinity of the structure to ensure that the prepared structure is not compromised by intentional or inadvertent acts by others. 3. Ensuring that the property owner/client and regulatory representatives understand the importance of establishing and maintaining an adequate blasting area in consideration of the structure being felled, the type/quantity of explosives being used and the risks associated with the project.
CDR: How does risk and preparation increase according to the size and scope of the project?
ML: The risk that increases with the size of a project is generally commercial. That risk associated with preparing a structure is generally related to actual structural conditions, the nature of the force system created within the structure to be felled and the proximity and nature of adjacent improvements to remain.
MSC: The risk and preparation of a job is directly related to the proximity to adjacent structures and whether the job is in a rural or urban setting. For instance, the requirements for taking down the Georgia Dome in the middle of downtown Atlanta are far more extensive than taking down a smokestack at a closed rural power plant in Waterford, Ohio. The risk in each case, along with the impact to the surrounding community, is what directly drives the amount of coordination and preparation needed for the implosion event.
CDR: What types of implosion projects tend to be the most seamless, and what jobs are the most difficult?
MSC: Rural jobs with very little community interaction that are located in an isolated area are the most seamless. The urban jobs in the middle of a town are the most difficult. The other variable that adds a huge degree of difficulty regardless of the setting is how close in proximity we are to other structures. This creates some extensive protection requirements.
ML: Implosion projects designed and executed by an experienced, competent blasting contractor who has the complete professional support of its client, the property owner and regulators will go well. If a blaster ventures too far out of his envelope of experience, risks go up dramatically for everyone involved, particularly under the strict liability nature of explosives handling operations.
CDR: How has technology changed how structures are imploded?
ML: The dependable production of linear-shaped charges that work predictably had a dramatic impact on the range of structural steel projects. The development of non-electric initiation systems dramatically reduced the risk of premature initiation because of static, stray current and other electrical sources.
MSC: The explosives that have been generated from military usage over the years have helped advance the ability to perform more precise techniques.
CDR: What kinds of training or continuing education do you undertake?
ML: CDI has a recurrent training program for our in-house employees that is conducted by in-house senior personnel and third-party specialists.
MSC: There are stringent licensing requirements put in place by the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) to become what is known as a federal explosives licensee (FEL). There are extensive background checks, fingerprinting and other requirements to get this license. To order and receive the required explosive materials for a given project, you need this special licensing. This licensing, and any required continuing education, varies by state. There are also very specific and rigid requirements for the handling and storage of the explosive materials as required by the ATF.
The author is the editor for Construction & Demolition Recycling and can be contacted at aredling@gie.net.
Adam Redling
