Concrete finds host of new applications

Concrete has been around a long time. In Rome’s spectacular Colosseum, ancient Greek temples and fully waterproofed aqueducts now 2,600 years old, concrete was the building material of choice.

Today, we still rely heavily on concrete for everything from massive infrastructure projects, such as highways and bridges, to traditional parking garages and home basements. But now concrete is finding its footing in a variety of new and creative uses.

One of the most popular and fastest-growing applications for concrete is flooring. Architects and builders of retail stores, restaurants, offices and even some homes are drawn to concrete’s surprising flexibility. It can be acid-stained, painted, inlaid, stamped and treated in other ways to create unique and striking floors. Even the more complicated designs and treatments can cost the same or slightly less than marble, granite or slate. And concrete offers a longer, and virtually maintenance-free, life than other flooring options. It’s also very energy-efficient and ideal for use with floor-laid radiant heating systems.

Concrete has also become a popular option for counters, whether in a home or restaurant kitchen or in other retail and commercial outlets. Like the flooring, concrete counters can be customized with paints, stains, patterns and inlays to produce a distinctive look at a reasonable cost—and they last long and wear well.

With the introduction of overlays, concrete has also shown its adaptability to decorative vertical surfaces. High-quality overlays, such as Arclin’s 2252 and 2253 High Density Overlay (HDO) can produce a sleek, architectural finish on concrete that is as attractive as it is strong. Builders and architects are using concrete overlays to create beautiful contemporary surfaces inside and out.

Multi-family and mixed use projects drive recovering construction market

Driving much of the construction industry recovery is a particularly strong U.S. market for mixed-use communities and high-rise residential buildings, according to the American Panel Association (APA), which predicts a 40% rise in multi-family construction in April 2014, following a 32% gain in 2013. (Commercial building not associated with mixed-use development is recovering, but not as quickly.)

“The mixed-use trend is really strong in North America,” echoes Ed Moroz, sales manager at Savona Specialty Plywood in Kamloops, British Columbia.

By contrast, single-family starts grew a not-insignificant 16% in 2013, according to the APA. Increases in mixed-use development, high-rise construction and an estimated 1.1 million in 2014 U.S. housing starts together bode well for the concrete construction business. And, by extension, the overlay business (BBOE plywood still outpaces the cost of overlaid panels by 10 – 15%).

Traditionally, too, as building starts improve, they’re quickly followed by growth in infrastructure improvements. “We’re seeing a significant amount of product going to projects like bridges and overpasses to meet the increased traffic that follows residential growth,” says Moroz. “That’s going to be a strong market for quite a while.”

Efforts to “reduce, reuse, recycle” in the building industry have taken on new meaning in recent years. Certainly, the environmental benefits are foremost. For many of us, reuse and waste reduction efforts offer tangible benefits to our bottom lines.

Take concrete, for example. Blast-furnace slag from iron processing and fly ash removed from power plant emissions — once environmental and waste nuisances — are now frequently added to concrete mixtures, ridding industry of caustic wastes and, in turn, helping create a tougher, more durable and less expensive concrete mix.  Win-win, right?

Well, yes…but. These additives yield concrete with a much higher alkaline content than purer mixes, which can create a pretty serious challenge for most concrete forming overlays. Which is precisely why Arclin developed a High Alkaline Overlay (HAO), specially crafted to perform with these mixes.

Arclin Technical Director Dave Gibson explains, “Our HAO has been engineered with a special polymer that resists high alkaline mixtures better than most overlays. It’s easier for the panel manufacturers — it requires one sheet versus multiple sheets of Medium or High Density Overlays (MDO/HDO) often used for caustic mixes — and it outperforms past solutions on the job site.”

Win-win.

Arclin’s HAO may help contribute to LEED MR Credits 2.1 and 2.2 for waste reduction and MR Credits 3.1 and 3.2 for material reuse. It’s E-Gen^® certified, and may be available with FSC^® chain of custody certification.

Contractors, specifiers continue to use more expensive materials

It seems like a no-brainer:  BBOE is more expensive today than conform panels with MDO overlays. MDO panels offer up to twice as many re-uses as the BB panel, give a better-looking finish and can significantly reduce jobsite waste and contribute to LEED credits.

So why then do some contractors continue to use raw BB?  In a word, says Jeff Linn, responsible for plywood mills sales for concrete construction chemical manufacturer, Nox-Crete.

The choice of BB is rooted for many in the confidence that comes with dealing with familiar materials and with a lack of understanding among specifiers, architects and contractors of the advantages of overlaid conform panels over BB.

(Further proof of value:  Arclin’s Enhanced Flow MDO adds an additional three to five pours to traditional MDO. A quick look at the math proves that one extra pour pays for the cost difference between the panels. And its resistance to alkaline concrete mixes helps the panel last even longer plus creates a better finish.)

So as an industry, how do we combat habits among our downstream product users that are costing them needless time and money and avoiding clear environmental benefits?

In another word:  education.

“All of us in this industry can help educate our downstream customers,” says Linn. “We need to collectively provide resources and training so they can better understand the variety of forms available and how to pick the right form for the job at the best value.”

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The overlay is just the surface of a conform panel 

To get a quality conform panel, you have to start with a quality overlay. But, says Ken Pratt, Operations Manager of Olympic Panel Products, “if you put a great quality overlay on a poor quality panel, you’re not going to get the performance you want.”

A lot of different factors affect a panel’s quality, Pratt says, starting with the veneer.  “A quality veneer should have the right thickness and smoothness and be dried to the right moisture content.”

“The type of adhesive you use and the average glue bond make a big difference in how the blackjack online panel will perform in the field,” Pratt details. “Then there’s process control on the hot press. All of those elements have to be considered and addressed to make a good panel.”

Pratt advises panel purchasers “Go to the mill. If I were a contractor, I’d be asking my supplier if there were someone at the plant to provide technical support and answer questions. That’s critical.”

Good advice can also help reduce costs. “Olympic makes 10 different conform panels with nine different overlays and four species of wood. A concrete contractor may order Multi-pour, Classic, Barrier Film and High Flow panels for a job. But with some guidance, that contractor may discover that Classic and High Flow panels alone will do the job. That can save a lot of money and deliver a quality product.”

DRILLING DOWN: Judging a conform panel

• Overlay should provide the right finish, stand up to the concrete mix
• Veneer should be smooth and dried to less than 8% moisture content
• Check veneer thickness and size of deficits
• Glue bond should be 90% or more
• Keys to a good bond: intimate contact, time and heat
• Check patch material, sanding, cleanliness
• All edges should be sealed

Answering tough questions means listening with intent

Arclin recently heard from a customer that one of our concrete forming overlays that was supposed to provide 10 or 15 uses was only lasting for about six pours on some jobsites.  Of course, we immediately set out to discern the issue — and discovered the problem wasn’t with the overlay at all, but was being caused by the concrete, itself. “Changes in the concrete formulations made them much more alkaline, and that was shortening our overlays’ life,” says Arclin’s Product Manager of Plywood Overlays, Gordon White.

In response, Arclin has been working on new overlays custom-designed to stand up to these new mixes.

Product and jobsite changes plus advancing technologies http://www.phpaide.com/?langue=fr&id=16 mean we’re constantly reviewing panniekazino.com and evolving our conform products to ensure maximum performance.  The first step in the process of evolution, however, is…listening.

As a senior account manager with Universal Forest Products in Ft. Worth, Texas, Kirby Mano has a lot of experience listening to customer complaints and expectations. In one case, he says, the customer found that vibrating concrete was damaging the conform panels used to shape columns.

“It turned out to be a very inexpensive fix. The customer just needed to use a different type of vibrator tip to avoid the damage.” Since then, Mano explained, “I’ve been able to take that knowledge to other job sites and prevent problems before they ever started.”

White and Mano both know well, too, that construction job purchasers often base their ordering on cost alone — and that can lead to product performance issues. “You get what you pay for,” White says. “A cheaper panel will not give the same stability or stand up to re-use. When you source these products you have to figure in the strength, the life and the finish as well as the cost.”

Judging the quality of a conform panel takes some know-how, and getting the best panel for your job may cost a bit more. But in the final analysis, the results will speak—and pay—for themselves.

Care and handling

Proper care and handling on the jobsite can maximize the life of conform panels and ensure you get the number of pours you expect. Here are some tips:

• Before first use, coat the panels with the proper form release agent. Arclin recommends Nox-Crete form releases (or equivalent).
• Clean panels after each use with burlap or flat plastic or wood scrapers that won’t damage the face of the panel.
• Reseal cut edges or exposed wood, at holes or openings, with two coats of a good quality, exterior edge sealer. (Arclin recommends Edge-Flex 645 or equivalent)
• Store panels flat and keep them in a protected area before use.
• Use rubber-tipped vibrators and avoid gouging the panels when vibrating concrete.
• Use wood wedges, not metal bars or pries, to separate the form from the concrete.
• When cutting panels, use carbide tip saw blades that are sharp. Make sure the saw is cutting into the overlay (cut with the overlay facing up, to minimize chipping).
• For form fastening, wood screws are recommended. Pre-drill pilot holes for screws using “screw pilot drill bit” sized appropriately for screw size. These bits are tapered for drilling pilot holes and also countersink the hole to minimize any cracking around screws.
• Avoid using nails as that may result in cracking of the panel face when the nails are set flush.
• Ensure proper spacing to allow for panel expansion.
• Use suitable tape or expandable caulk to seal panel joints.
• When drilling, ensure all drill bits are well maintained and kept sharp, for drilling tie holes a spur point bit will work well.
• Use a backing board when drilling panels for less splintering of the panel backs when the bits exit the panel.
• In hot weather, clean and reapply form release as soon as possible. The form release application will help minimize dry-out of the panel face.
• When stacking panels, ensure they are stacked face to face.
• Follow the appropriate pour rate to keep avoid damaging the panel.
• Lower the panels—don’t throw or drop them—to avoid damaging the edges and face.
• Remove fasteners to prevent damage and warping.
• Repair damaged areas with fast drying polyester, polyurethane or epoxy patching materials

On the surface, concrete doesn’t seem very ‘green.’ In fact, producing one pound of Portland cement results in the release of one pound of carbon dioxide.

But under the surface of concrete structures being built today lie some ancient techniques and waste materials that, says Matt Dalkie, Technical Sales Engineer for LaFarge North America, “are making concrete a much more environmentally friendly product.”

The secret lies in the use of pozzolans—siliceous material that reacts chemically with calcium hydroxide to form compounds that mimic the properties of cement. Pozzolans such as pottery shards and volcanic ash have been found in the ruins of ancient walls and buildings where they helped strengthen the structures and made good use of what would otherwise have been waste material.

Today, supplementary cementitious materials (SCMs)—such as fly ash from coal-burning power plants, slag from pig iron manufacturing and silica fume from the production of silicon metals and alloys—are used to extend concrete mixes, replacing a proportion of the Portland cement used. And because cement is the most expensive ingredient in concrete mix, that means lower costs.

Not only do these SCMs reduce costs, Dalkie explains; they also improve performance. “SCMs behave differently than ordinary cement. Fly ash, for example, helps to ‘lubricate’ the mix so that it requires less water. That means the concrete sets up faster, is stronger and is more durable.”

Using SCMs also can contribute to LEED credits for lowering energy use and  CO2 production, reducing waste, and recovering structural materials. So too can the use of concrete overlay forms, which offer additional benefits by allowing more re-uses than BBOE, among other advantages.

Dalkie asserts that concrete has another key environmental benefit. “In terms of sustainability, I believe its durability makes concrete the ‘green’ building product of choice.”