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.

Expediency is critical in the demolition industry. In order to be profitable, contractors have to work quickly to get in, out and on to the next job in as little time as is possible.

However, there is a case for a more nuanced approach to demolition, according to Damon Carson, founder and president of Denver-based Repurposed Materials Inc.

With offices in Denver, Chicago, Atlanta, Dallas and Philadelphia, Repurposed Materials buys materials throughout the country that would otherwise be discarded and sent to landfill and sells them to individuals and businesses where these items have a chance at a second life.

Understanding deconstruction

According to Carson, repurposing is different from the traditional recycling and reuse applications that contractors might be familiar with.

“Repurposing materials, for definition purposes, is taking byproducts and waste from industry and finding value for use ‘as is’ in a second industry,” Carson says. “Recycling traditionally requires taking a material and converting it to something else via chipping, shredding, grinding or melting. Reuse is something we’re all familiar with, and you can use boats, forklifts and refrigerators as examples. There is a secondary market for all these things to be sold off where a boat will be used as a boat, a forklift will be used as a forklift, and a refrigerator will be used as a refrigerator, etc. So, they have the same function even after going to a second buyer. Repurposing, by contrast, is using a product or material in a different capacity than what it was created for to give it a very different second life.”

Carson uses the example of a typical fire hose used by fire departments throughout the country. Once these age, malfunction or are decommissioned, they are no longer useful for helping fight fires. Although they have no utility for the purpose for which they were created, Carson says they still can be used by boat dock owners, for example, who can use the hose for bumpers or fenders to protect fiberglass boats from damage against wood or steel docks.

It is this eye for finding materials that can live on after demolition that can help contractors generate revenue from materials that would otherwise be discarded. While this can be lucrative, it often requires a different approach to demolition that has its trade-offs.

“Demolition contractors bid jobs, and speed is of the essence,” Carson says. “They’re thinking, ‘How fast can I get this building on the ground?’ And in most cases when something is repurposed, it needs to be preserved, so there has to be a deconstruction or disassembly mindset with that, which usually means more labor hours. So, it’s always a trade-off between getting value for the materials in the project you’re working on and working quickly, and the contractor has to do that analysis on a project-by-project basis.”

Finding end markets

When it comes to applications for repurposing, beauty—and value—is in the eye of the beholder.

There is virtually no limit on what materials found on the job site can be resold by contractors. However, part of the decision on whether or not to landfill material will be dictated by how easy it will be to resell the repurposed items. That’s where companies like Repurposed Materials come in.

Instead of having to search for buyers themselves, contractors can utilize third parties to take the hassle out of the process.

“Obviously, contractors can sell these materials themselves, but they have to let the world know what they have in their possession,” Carson says. “That comes with a cost for advertising, which is not insignificant. Then there is the time component. That steel beam, or whatever the material is, is probably not going to sell within 48 hours. It might take weeks or months to find a buyer for that. In the meantime, the contractor has to think about where they’re going to store this material while they wait for the buyer. Certainly, if a contractor can find a buyer themselves, they’re going to make more money. There is no question about it, but they have to think about advertising costs, all the work that goes into finding a seller, and the hassle of potentially having to store the material for prolonged periods. I think in many cases, demo contractors feel like they’re good at demoing buildings, but might not be so interested in selling their salvage, so that’s where going through a third party makes sense.”

Contractors looking to outsource the selling of their products have different options. According to Carson, different cities have different end markets. Traditional brokers can be used to find a home for the material in question, but they often look to find a buyer while the material stays in possession of the contractor or on the job site and then pay the contractor once a buyer has been found. Depending on the product, this can happen quickly or take months.

Other companies, such as Repurposed Materials, buy the material outright from contractors, so the need to find a temporary home for the repurposed materials is negated. In this case, all the contractor needs to do is send detailed information such as pictures, dimensions, descriptions, quantity, make/model—if applicable—and location of the material. The third party will then come back with an offer if it is something they think they can sell.

The economics of repurposing

In order to gauge the economics of repurposing materials, Carson says variables like labor hours, resources required, potential material end markets and disposal costs should all come into play.

“Where repurposing really makes sense is when it’s easy, for example, if you’re working on a school gym floor,” Carson says. “How much more effort would it take to rough cut 4-foot by 8-foot sections of wood by hand versus taking a skid steer and scraping everything up? By hand doesn’t take a whole lot of extra work, necessarily, but can make financial sense if you can find a home for the material. If a contractor spends 10 percent more time demoing a floor, but saves four dumpsters and finds a home for the material, they have to weigh these things and get out their calculators to see if it is the right move for the job.”

Another area where repurposing can make financial sense for a contractor is when the need for diversion is written into the contract. For example, many projects where sustainability and zero waste is emphasized, such as on a school demolition, can be aided by repurposing.

“On these types of green projects, the client might say that they want a 70 percent diversion rate, or whatever the number is, and the contractor has to be able to meet that,” Carson says. “Things like concrete might be easy to recycle, but then you start to think about what is going to happen with the roof insulation and a million other factors. So, hitting a 50 percent diversion rate might be easy, but you might have to get creative to meet your goal. That’s where repurposing plays a role. Everyone knows what to do with jackhammered out concrete and steel rebar, but there are a bunch of materials that don’t have a natural recycling outlet and repurposing becomes a viable option to keep these things out of landfills.”

Although deconstruction often requires more planning for contractors, being able to show an ability and willingness to find a new home for would-be landfilled material can be just what it takes to win a bid in today’s competitive climate.

“In the old days, it might’ve been about who could come in with the lowest price to knock a building down,” Carson says. “Now, there is new criteria being written into contracts. Price might still be the most important consideration on a lot of jobs, but contractors who can show they’re able to divert more material from landfill might still win a bid even if they’re not the lowest. Demo contractors might hate seeing this type of language put into contracts because it makes more work for them, but if the client is demanding, companies like ours can help and it doesn’t have to be quite so painful.”

The author is the editor for Construction & Demolition Recycling magazine and can be contacted at aredling@gie.net.

Demolishing a structure without disturbing the public at large can be a challenge on some jobs. When the job at hand is a stretch of California highway bridge, the need for organization, on-site management and timeliness needed to prevent disruption is increased exponentially.

That was the challenge presented to Mountain View, California-based Ferma Corp. when they were awarded the contract by Livermore, California-based RGW Construction Inc. in February 2017 to take down a stretch of highway bridge between Interstate 880 (I-880) at the existing overcrossings of 23rd and 29th Avenues in Oakland, California. RGW was contracted directly by the California Department of Transportation (Caltrans). This demolition was scheduled from July 7 to Sept. 29, 2017, to make way for operational and safety improvements, with a second stretch of bridge slated to be demolished starting in October 2018.

On the clock

Ferma Corp., which is a full-service general engineering firm that concentrates on demolition, site preparation, excavation, grading, recycling, shoreline restoration and protection, paving, hazardous waste remediation and landfill construction and closure, was founded by four brothers and a partner in 1963 as a site-clearing business. Three generations later, Ferma Corp. specializes in large fast-track demolition projects of buildings and structures constructed of heavy steel and concrete. Their sub-niche is performing this style of demolition on structures of significant height, which made them perfect candidates for the Caltrans bridge demolition.

According to Marc Ferrari, president of Ferma Corp., once the company was awarded the job, it went to work immediately collaborating with Caltrans to plan the demolition in the most effective way.

“We worked with a structural engineer during the implementation stage to not only accommodate previous commitments by past involved contractors, but to include Ferma's resources in the design of the bridge removal,” Ferrari says of the Caltrans collaboration. “This was a challenge as the owner had previous demolition plan submittals, and Ferma had to convince Caltrans there was a better and safer way. Working with the structural engineer, Ferma submitted several updated demolition plans and drawings to make the general contractor and Caltrans comfortable with past commitments while implementing methods and means that Ferma was comfortable with.”

To prepare the bridges for the demolition, Ferrari says Ferma created a “by the minute” construction schedule to ensure it'd be in compliance with the strict lane closure restrictions. The company sourced backup equipment for redundancy in case of breakdowns, brought an extra trench plate on-site for freeway protection and designed special debris trailers to be placed under the spans to catch the concrete rubble to expedite the cleanup at the end of each shift.

“Once an approved demolition plan was accepted by the owner’s team, the general contractor placed the traffic controls and lane re-configurations, and we were on the clock,” Ferrari says.

Over a span of 10 night shifts and 20 day shifts, Ferma Corp. was tasked with removing the existing bridge to make way for a new over-crossing bridge.

Because of the tight time frames, expediency was the key to staying on schedule. According to Ferrari, this was exacerbated by the threat of a $25,000-per-hour penalty levied by Caltrans for missing a lane opening.

“Ferma had 10 night closures with a four- to five-hour window to remove approximately 300 linear feet of bridge, including six 70,000 to 90,000 pound steel girders, concrete deck and bents over I-880. We also had to remove another 350 linear feet of bridge on each side of the freeway during the day shift,” Ferrari says. “The night closure included the time for the general contractor to close the freeway as well as time for Ferma to place protection on the 880 freeway to protect the roadway and cleanup time.

“We placed shoring towers under the girders and torch-cut the girders in half during the closure so our 90-ton rough terrain crane could pick each girder in two pieces. The reason for this was the closure hours were so tight that there was no time to set up a conventional crane. To perform four picks per shift in the four- to five-hour closure time was impressive.”

The tools of the trade

To conduct the tear down, Ferma used multiple 100,000-pound excavators to remove the 25-foot-wide deck along with the cantilevered sidewalk on each side of the bridge. Since the bridge was located close to residential neighborhoods, the excavators were equipped with crunchers and shears to eliminate the noise of using a breaker. The deck was removed to expose the girders so Ferma could prepare them for the next closure’s crane pick.

“In essence, Ferma had two to three working hours each night shift to accomplish the removal of 8,750 square feet of concrete deck with two layers of rebar,” Ferrari says.

Thanks to the company’s emphasis on comprehensive planning and adherence to its deadlines, Ferma Corp. was able to complete the scope of work in the amount of closures specified. And despite its expedited schedule, recycling was at the forefront of the project, according to Ferrari.

“One-hundred percent of the steel and concrete removed from the site was recycled, and all the material brought in for protection was removed and will be reused on other projects,” Ferrari says.

All the concrete from the project was sent one mile down the road for recycling, which minimized the trucking needed for transport. All of the steel derived from the project was sized so that the maximum amount could fit into the trucks for transport, which further reduced the company’s hauling footprint.

Beyond recycling, Ferrari says that Ferma Corp. took a green approach to selecting the equipment to be used in the project.

“All equipment used was Tier 4 equipment, which greatly reduced toxic emissions during the demolition,” Ferrari says. “Dust was suppressed using updated attachments, thus minimizing the use of water as dust control.”

Ferrari credits the expediency and seamlessness of the project, in part, to the company’s insistence on investing in the right equipment for the job.

“Owning the largest hydraulic shears, hammers and processors the country has to offer mounted to the nation’s largest fleet of heavy high-reach excavators allows Ferma to demolish high-rise structures at a pace that exceeds what most in our industry achieve in a low-rise environment,” Ferrari says.

The takeaway

Beyond the equipment, Ferrari says that working with a team capable of adapting to challenging conditions on the fly was the differentiator that helped make the Caltrans bridge demolition a success.

“The takeaway is that many jobs are similar, but each requires unique engineering and planning,” Ferrari says. “The work environment is changing with new rules and regulations constantly being amended or added. These changes require our team to be fully aware of current regulations in order to stay in compliance.”

Ferma Corp.’s commitment to going above and beyond on the Caltrans bridge demolition did not go unrecognized. Thanks to their emphasis on recycling and reducing the environmental impact of the job, Ferma Corp. was recognized by the National Demolition Association (NDA), Washington, which awarded the demolition contractor with the 2018 Excellence in Demolition award in the $500,001 to $2,000,000 category Feb. 24 at the NDA's Demolition Austin event.

The Excellence in Demolition award honors NDA members who have demonstrated significant environmental conservation and community involvement and is presented annually to companies that have made a significant "quality of life" impact on their community, according to the DNA.

“Winning the 2018 Excellence in Demolition award means a great deal to Ferma,” Ferrari says. “It’s not just an award; it means that our peers have acknowledged our efforts and achievements in evolving our trade."

While the award was great to receive, Ferrari says, the symbolism of what it embodied was even more important for the his team.

“It represents growth and opportunity for success as a team,” he says. “It takes courage to start every project and determination to complete the job and make our mark. The opportunities are out there for us to be successful as long as we stay true to who we are as a company—honest, hardworking individuals who are committed to working safely so that all of our coworkers return to their families at the end of their shift at least as good as they arrived to work that day.”

The author is the editor for Construction & Demolition Recycling and can be contacted at aredling@gie.net.

Cleveland convention center reports diversion rates from 2017

Several tons of material generated at the Huntington Convention Center, Cleveland, which is managed by SMG, West Conshohocken, Pennsylvania, was diverted from landfill during the center’s 222 events in 2017, a report by Cleveland.com says. Last year’s events attracted 22,656 visitors.

The center diverted the following:

• 75,880 pounds of cardboard;
• 46,440 pounds of wood pallets;
• 18,480 pounds of mixed plastic;
• 14,780 pounds of mixed fibers;
• 10,000 pounds of glass;
• 9,000 pounds of bulk and shredded paper; and
• the equivalent of 23,005 plastic water bottles from the use of water refill stations.

According to the report, the convention center also donated 26,980 pounds of recycled material, including leftover carpeting, insulation, gardening equipment, fertilizer, building materials, drywall, tools, children’s furniture, paint, landscaping brick and trim to local organizations such as the Habitat for Humanity ReStore, the Ed Keating Center and Karamu House.

An on-site working farm operated by Levy Food Services, Chicago, and SMG provided more than 2,000 pounds of honey from 16 bee colonies; a quarter of the facility’s eggs from hens; and seasonal greens, herbs and veggies to the facility.

Levy also diverted nearly 25,000 pounds of food at the Huntington Convention Center by donating 13,500 pounds of leftovers to the Ed Keating Center through the Greater Cleveland Food Bank, recycling 1,650 pounds of cooking oil and feeding 9,000 pounds of food scraps to the hens and three pigs that live on-site, the report says.

The convention center also reduced napkin waste by 56 percent through one-at-a-time napkin dispensers, used biodegradable and compostable plates, box lunches, cups and flatware and implemented a food waste recycling system from Grind2Energy, Racine, Wisconsin, that created 37.8 tons of slurry from food waste. The slurry is sent to an anaerobic digester that extracts the methane for energy production and soil amendment.

The facility also makes a biannual donation of clothing, coats, gloves and other items from the building’s lost and found.