Summer 2009
form function
News & Information from Hamilton Form Company
FORMWORK
Round Column Form for Mohave County Sheriff Building
he new Mohave County Sheriff's office in Kingman, Arizona is being built with some typical precast concrete products; 32" and 24" double tees, beams, rectangular columns and three different thicknesses of exterior walls. The project also calls for 36 round columns. Coreslab St r u c t u re in Phoenix, Arizona is supplying the precast products, 839 pieces s in all, and doing the erection. Most of the precast products are being produced with existing formwork, but the round columns required a new form; so they called on Hamilton Form. Hamilton Form's engineer Taylor Slate, worked closely with Mark LoStracco at Coreslab, to design a 28 inch round column form that would produce a quality product and maximize efficiency in set-up and stripping. The form consists of a half round column base, capital base and sideforms; a hinged half round column top and capital top plate that bolts into place with Hamilton Form speed bolts. The top and bottom skins on the column interlock for alignment and help minimize seam appearance. Two different column heights are required. A filler was made to accommodate the height change from 20 to 17 feet. The capital area is 6 foot, 2 inches high with bearing ledges on each side. The columns we re poured horizontally. To help concrete flow, shims were used to raise the upper end of the form 4 inches. External vibration was used for consolidation and to reduce air pockets. To help the project's sustainability goals, Coreslab used a self compacting concrete mix with 30 percent fly ash and 100 percent recycled rebar. In addition to the recycled content, the columns will be left unpainted to add to the sustainable features. "The form was easy to set-up and handle," said Gene Blackwell; production manager at Coreslab. "Stripping was easy with no spalling issues. It took less than 30 minutes to strip, and the form was ready to be set-up again." Gene also estimated that using the form saved about 4 hours of production time per day. Mark LoStracco noted "Some finish work needed to be done on the columns, with each taking 1-1/2 to 2 hours, which is pretty good on a round column." Erection is beginning this summer and the new Mohave County Sheriff Building is scheduled to open in the fall of 2009.
Product required very little finishing.
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Round column form at Coreslab Structures.
The form was set-up on a slight slope to aid concrete flow.
External vibrators help consolidate concrete.
PROJECT SP OT LI GHT
Valley Prestress Streamlines Deck Slab Production
Project: Highway 161 Toll Road, Dallas County, TX
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tate Highway 161 in Dallas is an 11.5 mile toll road that will relieve congestion and provide a vital north/south link from DFW Airport to the stadium and entertainment district in Arlington. Designed as an all-electronic toll road, it is scheduled to open on a phased basis in August. Williams Brothers Construction Company has the $215 million contract for the project. The majority of the project is bridgework: including 45,000 feet of drilled shafts; 60,000 cubic yards of concrete substructure; 384,000 feet of concrete beams; 10 million pounds of structural steel; and 3.1 million square feet of bridge deck. Valley Prestress of Eagle Lake, TX is supplying precast concrete products for Williams Brothers. Bridge girders are produced in the company's Eagle Lake location and shipped to the jobsite; while the deck slabs are being produced close to the construction site, saving shipping costs and transportation time. Hamilton Form provided the formwork for the girders and deck slabs. To streamline production and improve productivity, Hamilton Form also designed three different utility machines for use in production of the deck slabs. The machines not only mechanize production, but also improve safety.
Five 400-foot self-stressing casting beds are being used to cast the 8-foot deck slabs. Forms were designed so they could be easily installed and feature wide shelf angles to support the utility machines. A run out track is installed at the end of each bed for machine storage. The utility machines save a significant amount of time. Operations that took four or five men working on a bed are accomplished in a fraction of the time with one man. Some of the most difficult manual operations are automated, saving wear and tear on the crews and improving safety. "For this project, we are producing a large volume of the same product, which lends itself to automation;" says Brian Malaer of Valley Prestress. "The production machines that Hamilton Form designed for us have been very effective in improving efficiency. They've helped us decrease production time and improve costs, which is the name of the game in high volume production." Productivity improvements easily justify the expense, and the fact that each machine can be used on multiple beds makes the investment even more attractive.
Major road construction projects, like State Highway 161 in Dallas, represent an ideal venue for the application of automated machinery and processes to expedite production in an efficient and cost-effective manner.
EQUIPMENT SP OT LI GHT
Utility Machines Combine Tasks to Improve Cost and Efficiency
Form Cleaning, Strand Puller, Oiler Machine
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his machine aids set up by providing form cleaning, oiling and strand pulling operations. The machine is driven by a diesel engine over hydraulic power. The operator rides on top of the machine and controls all of the functions. Two side wall brushes clean the sides of the form, while an 8-foot flat deck brush cleans the deck and pushes debris to the end of the bed. Brushes are raised and lowered hydraulically. The double brush configuration allows the sides and the flat surface to be cleaned in a single pass. The speed of the machine can be adjusted depending on the amount of debris on the bed. One man operates the machine. A process that could easily take three or four men to complete is done in less than one fourth of the time by a single operator.
After the casting surface is cleaned, the machine makes a pass down the bed using the sprayer on the other end of the machine to evenly distribute release agent. The spray is shielded from the wind with vinyl skirts installed in front and on the sides of the spray deck. Next up is the strand puller. The strand puller can pull as many as 8 to 10 strands at a time, dropping strand into each header along the bed. Depending on the number of strand packs at the end of the bed, the puller makes a second or third pass to complete the operation. The strand puller makes a significant contribution to improving productivity. One man drives the machine, pulling 8 to 10 strands at a time is a vast improvement over pulling strand by hand. Manually pulling strand on a 400-foot bed is not only difficult, but potentially hazardous on a slippery surface.
Double brushes allow the form side walls and flat deck surfaces to be cleaned in a single pass. The spray deck is located at the back of the machine, vinyl skirts block the wind.
As many as 8 to 10 prestressing strands can be pulled and dropped simultaneously into each header along the 400-foot beds.
Controls for the finishing machine are located on the side for easy access and to visually check the process. A high frequency pneumatic vibrating screed raises and lowers hydraulically, as needed, to speed concrete consolidation.
A dedicated tarp roller is assigned to each bed. Run out tracks at the end of each bed keep tarps online as needed.
Concrete Consolidation and Finishing Machine
The next machine to work the bed is a finishing machine with a vibrating screed. The screed lifts and lowers hydraulically. Controls are located to the side of the machine so an operator can walk along the bed to observe the process to time the amount of vibration needed to complete consolidation. The machine also has a drag broom attachment for finishing. Once the concrete is partially set, the machine makes another pass along the bed with the drag broom to create the longitudinal brushed finish specified by the DOT.
Tarp Dispenser/Roller Machine
Finally, an operator drives the Tarp Machine down the form and unrolls a custom made tarp cover across the bed for curing. When the bed is ready for stripping, the tarp is rolled up and stored on the same reel. Storing the tarp on the reel saves room at the end of the bed and reduces wear and tear on the tarp. A run out track at the end of each bed is used to store the machine.
PCI CONVENTION
Hamilton Form will be exhibiting at the 55th Annual PCI Convention in San Antonio, Texas; September 12-15, 2009. We hope to see you there.
The Hamilton Form Handy Epicurean Cookbook will be available at the Convention. You still have time to have one of your recipes published in this year's edition of the cookbook. Send your recipe to recipes@hamiltonform.com – or fax your recipe to 817 595-1110. Please stop by and pick up a new cookbook - or new recipes, and a special gift, compliments of Hamilton Form.
Precast/Prestressed Concrete Institute
TECHNICALLY SP EAKIN G
SAFETY TIP
Form Installation & Maintenance Tips
Safety Stretch at GPRM; Kapolea, Hawaii
Anchoring Long Line Forms
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orms move as they are stressed and with temperature changes. Because of this movement, long line forms should be anchored at the centerline of the bed. Centerline anchoring helps mange this movement by splitting the movement in half. Forms should be anchored only at the center; then clipped down about every five feet to maintain alignment and provide resistance to uplift, while allowing the form to expand and contract longitudinally. There are several ways that a form can be clipped, as illustrated below.
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ach day, production at GPRM Prestress in Kapolea, Hawaii begins with a stretch for safety – literally. Employees begin their day with stretching exercises designed to help prevent injuries. The benefits of stretching include: increase range of motion, improved coordination and increased energy. When you consider the fact that 4 out of 5 adults will develop some type of lower back pain in their lives, stretching to prevent injuries makes sense. Production work in a prestress facility is physical, making fitness a concern for management and employees alike. Jim Beaton, the Production Manager at GPRM explains, "The management team in Hawaii saw the program at the GPRM plant in Guam about 5 years ago and brought it back to Hawaii. We shared details of the program with employees during an interactive meeting complete with demonstrations and visual aids. Refresher meetings are also conducted." Stretching at the beginning of your shift is a condition of employment at GPRM, with consequences for noncompliance. Management takes the program seriously. And why shouldn’t they? Since implementing the program 5 years ago, there has been about an 80% reduction in lost time due to back and other muscle injuries.
EMPLOYEE PRO FILE
Bob Mills – Production Manager
For over 30 years, Hamilton Form has benefited from the strong work ethic and dedication that Bob Mills brings to the company. Bob started working at Hamilton Form while still in school; little did he know how long he was going to stay. From department to department, Bob worked throughout the plant gaining hands-on experience in every phase of production. He ran the press break, welded, did layout and finishing work, and worked as the lead man in virtually every department. Bob also spent time on the road doing field repairs and maintenance where he became very good at trouble shooting and learning the business from the customer's point of view. Bob has managed production at Hamilton Form since 1992. Over the years he has seen lots of changes; the ushering in of CNC cutting equipment and plasma cutting, two different plant expansions and the growth of the Equipment and Blanket Divisions. Under Bob's leadership, commitment to quality and lean production processes, he has continually increased productivity and throughput. Since becoming the Production Manager at Hamilton Form, the company has more than doubled its output with no further plant expansions. A prize winning chef, Bob has won numerous awards in Barbeque Competitions and for his chili recipes. He qualified several years to compete in the "International Chili Cook-Off" in Terlingua, Texas. You may have seen some of his recipes in the Hamilton Form Handy Epicurean Cookbook. Some of the best days to be at Hamilton Form are when Bob cooks. Several times a year, Bob cooks for the entire staff. Between the two of them, Bob and his wife Irene have 5 children, 2 grandchildren and 3 dogs. On days off, the family enjoys spending time kicking back at their farm in east Texas.
Form and Function Newsletter is available electronically.
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Hamilton Form Stocks One and a Half Inch Steel Chamfer
Several State DOTs are now specifying 1-1/2 inch chamfer on girders, beams and other cross sections. In response, Hamilton Form now offers steel 1-1/2 inch chamfer, in 10 foot lengths. We also have 1/2, 3/4 and 1 inch steel chamfer in stock and ready to ship. Call 817 590-2111 or e-mail: sales@hamiltonform.com
Hamilton Form Company, Ltd
7009 Midway Road • Fort Worth, Texas 76118 Ph 817.590.2111 • Fx 817.595.1110 www.hamiltonform.com