WITH POWERBLANKET POWERBLANKET HEATED CONCRETE CURING BLANKETS OFFER A MANAGEABLE AND REALISTIC METHOD FOR CURING CONCRETE IN COLD AND ADVERSE WEATHER CONDITIONS.
EXECUTIVE SUMMARY Massman Construction Co., also known as America’s Bridge Builder, excels at complex bridgework. While constructing Kansas City’s Christopher S. Bond Bridge they encountered a mid-winter dilemma. The bridge primarily utilized pre-cast concrete, but the panels left a 18-inch wide by 12-inch deep gap (46 cm x 31 cm). Unfortunately, the support beam beneath the bridge, which formed the bottom of the gap, was exposed to temperatures of -5°F (-21°C). Water in concrete can freeze starting at 30°F (-1°C) and at around 27°F (-3°C) the hydration process can stop entirely. Since ice occupies about 9 percent more space than water, this can seriously affect the integrity of the concrete. Massman concluded that the traditional solution of erecting a structure and heating up the ambient air temperature wouldn’t work in this case. They turned to Powerblanket heated curing blankets, which warmed up the surrounding concrete and support beam, and then kept a constant temperature on the concrete. This innovative solution finished the job. BACKGROUND In 2007 three companies - Massman Construction Co., Kiewit Construction, and Clarkson Construction Co. - formed the joint venture called Paseo Corridor Constructors, which received the design-build contract for the bridge. Construction started in April 2008. The overall project called kcICON cost $245 million and required the rehabilitation of more than four miles of Interstates 29 and 35 and a new bridge to replace the Paseo Bridge that has spanned the Missouri River since 1954. The Missouri Department of Transportation estimated the project would require 7,000 tons of steel and 50,000 cubic yards of concrete. In late 2009 Massman Construction Co. encountered a unique challenge in completing a critical portion of the new cable-stayed river bridge. COLD WEATHER CONCRETING The bridge deck design called for precast concrete panels, each weighing about 60,000 pounds (27,215 kg). The panels, which were designed to have post-tensioning bars installed, were formed in a precast yard and hauled to the bridge site.
POWERBLANKET PROVIDES THE MOST INNOVATIVE HEATING SOLUTIONS ON THE MARKET, DELIVERING SAFE UNIFORM HEAT.
EXPERTS AGREE THAT THE BEST TEMPERATURE FOR POURING CONCRETE IS BETWEEN 50-60 °F.
EXPLORING CONCRETE OPTIONS Massman contemplated various ways to generate the necessary heat. Although they felt confident that they could use portable heaters to heat the top of the fresh concrete, the support beam below the bridge posed a real heating problem. Massman’s crew decided they had to enclose the bottom to keep the bottom warm. To do that, they would come underneath from a barge on the river and hoist up a boxed plywood structure around the beam. Once in place, they would heat the air in the enclosure. However, after some number crunching, the high cost killed this option. The plan would take a long time to execute and it wouldn’t guarantee success. THE NEW SOLUTION Fortunately, the company connected with a local equipment dealer who had an alternative solution in the form of electric-powered concrete curing blankets from Powerblanket. Powerblanket products deliver contact heat. Helping to seal in the hydration and providing additional heat to keep the concrete within a desired temperature range, the blankets cured the concrete without cracking it. “We gave the engineers at Powerblanket the boundary conditions — at least 46°F (8°C) at the bottom but no warmer than 82°F (28°C) at the top,” said Helmig. “They performed the calculations and determined the appropriate blankets needed to get the job done.” Standard curing blankets could help heat the top surface of the poured concrete, but they could not adequately heat the entire 12-inch depth due to the extreme cold affecting the bottom portion of the slab resting on the steel support beam beneath the bridge deck. Massman used 34 Powerblanket Extra Hot Series blankets. Each came equipped with a digital thermostat to ensure that the blankets did not overheat the concrete. The thermostat allowed constant temperature monitoring. Because of the technology used by Powerblanket products, the heat spreads evenly, and even the corners and edges of the concrete receive protection. The thermal image above records how evenly the product spreads heat. In fact, 98% of the temperature data points measured within a range of 137°F to 147°F - only 10 degree difference (58.3°C to 63.8°C).
“It was awfully cold, but the blankets did their job keeping the concrete temperatures within spec,” said Helmig. “We achieved the PSI (Pounds per Square Inch] levels we had targeted, and it turned out to be a successful operation. We didn’t have the time to wait out the winter for the temperatures to become more moderate. The Powerblanket products certainly played an important role in keeping us on schedule and not having to postpone the pour.”
THE DETAILS The Powerblanket heated blankets used were 6 feet by 12 feet (1.8m x 3.7m), easily exceeding the 18-inch (46 cm) width of the trough. The additional blanket width was utilized to preheat the precast concrete panels that formed the sides of the trough prior to the pour. The preheating process helped minimize each panel’s ability to absorb heat from the freshly poured concrete. Using portable generators and junction boxes to supply power to the 120volt electric blankets, Massman initiated the weeklong concrete cure. In addition to relying on the blankets’ external thermostats, crew members used probes to take temperature readings several times daily to ensure that the engineering specifications were being properly met and maintained for the full seven-day period – during wihich the outdoor air temperature hit a low of -5°F (-21°C).
WITH POWERBLANKET POWERBLANKET TANK HEATERS MAINTAIN TEMPERATURE AND HEAT, PROVIDE FREEZE PROTECTION, AND OPTIMIZE FLOW FOR VISCOUS AND TEMPERATURE SENSITIVE MATERIALS.
URS Corporation implemented a new solution to keep ground water collected in frac tanks from freezing at the Knolls Atomic Power Laboratory. Located in Niskayuna, NY, the Knolls Atomic Power Laboratory (KAPL) is dedicated to the support of the US Naval Nuclear Propulsion Program. KAPL was developed after World War II in 1946 under a contract between General Electric and the United States government.
Today, KAPL is a government-owned, contractor-operated laboratory run by Bechtel Marine Propulsion Corporation for the US Department of Energy. KAPL is responsible for the research, design, construction,
operation, and maintenance of U.S. nuclear-powered warships, and manages work on nuclear ships at numerous shipyards across the country.
On January 7, 2008, the U.S. Department of Energy (DOE) awarded URS Corporation a $67 million task order to deactivate and demolish the Separations Process Research Unit (SPRU) located at the Knolls
Atomic Power Laboratory in Niskayuna, New York. The site, used for U.S. atomic weapon reserach, closed in 1953. Part of the operation involves collecting, transferring, and storage of ground water in frac tanks located on-site. URS Corporation realized they needed to keep the ground water in the frac tanks from freezing. They contacted Powerblanket® for a custom solution.
Powerblanket’s world-class custom design team accepted the challenge and delivered quickly to have the system in place in time for winter. This solution provided freeze protection, allowing for continuous operation and minimized downtime during the project. URS completed their project on time and on
budget thanks to Powerblanket’s custom frac tank heaters. CUSTOM TANK HEATING Powerblanket provides the most innovative heating solutions on the market, providing uniform safe heat. Our custom engineered wraps are no exception. With a full team of design engineers, custom heating solutions
provide maximum freeze protection for a wide variety of applications. Heating, insulating, thawing, and protecting fluids from harsh outdoor environments is our specialty.
Powerblanket is kicking off part two of its Share-the-Warmth campaign with November’s “Glovember” glove drive.
Powerblanket is kicking off part two of its Share-the-Warmth campaign with November’s “Glovember” glove drive. Employees and their families are encouraged to donate pairs of gloves suited to winter weather. As per last month, donations will benefit the Rescue Mission of Salt Lake.
Since 1972, the Rescue Mission of Salt Lake is dedicated to serving the 3,000 homeless Utahns who sleep on the street every night, 80 percent of which are located along the Wasatch Front. Every year, the Rescue Mission provides more than 73,000 articles of clothing to those in need.
Gloves are essential to staying warm during Utah’s winter months. Please take an extra minute to pick up a pair of gloves while doing your Thanksgiving shopping and help out our local Utahns!
In what seemed like an underserved market, one business has been leading the way in quality gun accessory manufacturing. That’s why the September Power Manufacture Award goes well-deserved to Stealth Gear USA.
How it all Began:
Based in American Fork, Utah, Stealth Gear USA was created on the idea of a better gun carrying case. According to the company’s website, founder Paul Laemmlen, it all started with a mishap with his handgun while shopping at a local store.
“It all started the day my loaded handgun fell out of a poorly-designed IWB holster and onto the floor of a busy retail establishment,” he says on the company’s website. “That holster (manufactured by a major US holster company) was retired that day to the reject holster pile. After an exhaustive search for a better IWB holster, I was disappointed with the poorly-conceived and over-priced offerings on the market.”
It wasn’t long before Stealth Gear USA was born, bringing quality and practical gun holsters and accessories to the world.
What truly sets Stealth Gear USA apart from its competitors is their carefully-crafted, award-winning, American made VentCore® holster. The product was one of Laemmlen’s original creations when he first designed the product out of his garage in 2012. With 30 individual components handmade to order, including parts that utilize rust-free metal and breathable fabric, the holster serves citizens, military and police forces in more than 50 countries.
Not your Average Gun Accessory Maker:
Stealth Gear USA isn’t content in participating in the latest trends in accessory manufacturing. According to a company spokesman, Stealth Gear USA seeks to be on the cutting edge of what’s next in the market.
“We don’t release a product unless its innovative or better than what’s currently available on the
Market,” the spokesman said. “Too many companies ‘pile on’ and just copy their competitors. With our Research and Development Department, Market Research Committee, and New Product Development Committee structure – which is composed of team members with significant engineering and product education experience and backgrounds – we believe we are capable of bringing a more robust and cross-disciplinary product development process to our products.”
Creating a Proud Legacy:
Getting into an industry market can be tough in today’s environment for small businesses. Stealth Gear USA knew this to be a fact, and strove to regulate its growth in ways that would allow its top-quality employees to be the drive of expansion and profit.
“Early on, it was very challenging trying to keep up with the overwhelming demand while building an underlying business that could support the demand and grow to meet market needs,” the spokesman said. “It didn’t take long for us to discover that our industry is subject to hyper-competition, political realities, and knock-offs and imitations. Through all these challenges we focused on what we could control – the quality of our products and our customer service.
Looking to the future, Stealth Gear USA says it’s well prepared to face a world where the market is ever changing.
“We are extremely proud of the team we’ve built and the processes we have refined over the past five years. We’re in a position now to aggressively pursue new and exciting products not only within the concealed carry market, but beyond.”
Powerblanket is proud to award the Power Manufacture Award to Stealth Gear USA due to the company’s excellence in manufacturing a quality product that puts them above the competition. Fore more information on Stealth Gear USA and its products, visit www.stealthgearusa.com.