Several recent projects display how MEVA's KLK climbing system and Imperial (inch-foot) sized forms contribute to efficient concrete construction.
In downtown Chicago, developer Robin Construction is currently building a 21-story high-rise condominium. General contractor AMEC Construction Management assigned Goebel Concrete Forming to do the concrete work. In order to meet the schedule and the budget—even through the tough Illinois winter—Goebel worked with Accurate Formwork, Chicago, to use MEVA's Imperial wall formwork system in combination with the KLK climbing system. The entire perimeter walls were formed with this fast roll-back system by using 8-foot and 1.5-foot panels to reach the wall height of 9.5 feet. Because the architects required a perfect tie hole grid, fake tie holes were drilled into the facing to achieve the required pattern. Accurate Formwork was able to do this with almost no additional cost because the facing did not have to be replaced afterwards.
In Madison, Wis., Dane County decided to expand its courthouse with a new eight-story building. Advance Shoring, MEVA's St. Paul, Minn., distributor, provided the KLK climbing system for nine vertical elevator and staircase shafts. Each was poured concrete; the two smaller shafts were four lifts, and the others were nine lifts. The MEVA KLK 230 jump system allowed Miron Construction to use MEVA Imperial Wall Forms and aluminum-beam gangs from their own stock. Assistant project manager Dan Carl said the KLK system allowed them to, “predictably schedule the form lift process, which enabled Miron to coordinate the tower crane schedule with the ongoing structural steel placement.”
In Louisville, Ky., at the crossing of three interstates, one of America's largest exhibition and convention centers is expanding. The $47 million project was awarded to general contractor Hall Contracting of Kentucky. The structure, with 80,000 square feet of walls, had to be completed within 15 months, so Hall was looking for a formwork supplier able to handle a project of this dimension. With story heights from 37 to 80 feet and with 100-foot-long shear walls, Hall's superintendent Cannon Kerr decided to rely on MEVA's Imperial wall formwork system. The shear walls were poured in 30- to 46-foot lengths and in two steps: the bottom portion was a 37-foot-high lift and subsequent pours were supported by the KLK brackets. The standard platforms (consisting of only two KLK brackets) were 16 feet long and were used for all pours.
At the Lake Cumberland Regional Hospital in Somerset, Ky., general contractor Abel Construction Company, Louisville, used MEVA forms for a new five-story tower. The most interesting part of the tower was four elevator and stair shafts. The panels on the outside were mounted to the rollback carriages of the KLK climbing system while the inside panels were placed on a shaft platform using MEVA's folding suspension. The shafts were poured in five steps: the first pour in a 12-foot lift, followed by four 16-foot-high pours. The wall thicknesses varied from 1 to 2 feet. An unusual detail was that one wall of one shaft was inclined, widening 1 foot every 16 feet of height.
Custom composite column forms
The New Central Library in downtown Minneapolis, scheduled for completion in 2006, will replace the outdated, nearly 100-year-old Central Library. The six-level structure is part of the Great Libraries of Minneapolis, a ten-year $166 million public/ private capital improvement partnership to upgrade all of Minneapolis' Public Libraries by 2010.
Designed by AIA Gold-Medal-winning architectural firm Cesar Pelli & Associates, aesthetic goals were key to the design. The landmark project, covering two blocks and 400,000 square feet required 400 columns that would be prominent throughout the facility. As a visual focal point of the project, the specifications required that the concrete columns, with their sloping capitals, have minimal seams and bug holes.
After reviewing paper and steel round column forming options, which didn't meet seam and one-piece vertical height requirements, St. Paul-based distributor Brock White Company contacted MFG Construction Products of Independence, Kan. (a division of Molded Fiber Glass Companies), to explore a composite solution. MFG produced a mock-up form made of fiberglass-reinforced thermo-set composite and made four pours to test the mix design and to check column finish and release agent requirements.
Having achieved the desired aesthetic and production results, MFG was selected as the sole supplier for the project's monolithic forms. MFG custom made the forms in two parts, shipped them to Minneapolis, then assembled them on-site. Forty forms were used to construct more than 400 columns. The building's first-floor columns are 19 feet high and decrease by 1 foot for each successive floor. The forms, therefore, were cut down, braced, oiled, leveled, and then poured for each subsequent floor.
Each of the 19-foot-tall by 40-inch-diameter columns required about 8 cubic yards of concrete. The 8000-psi mix had a high volume of cement, so the forms had to be stripped after only one day to prevent the cement from reacting with the fiberglass.
“Since the forms were designed and constructed for repeated use (with normal care and application of form release),” said Brock White Company's Roland Studler, “approximately 80 pours were achieved on each form with an average of five columns poured each day.” Studler also noted a deformation issue involving the capitals. “The capitals that were molded at the plant became out of plumb by ½ inch during transport. MFG personnel reacted quickly by performing cut, slice, re-epoxy, and re-brace adjustments onsite to ensure their horizontal uniformity and achieve the aesthetic design goals.”
Unlike paper or steel RCF, MFG forms are corrosion-resistant and can therefore be stored conveniently and economically outdoors. They also have the ability to nest/stack to reduce storage/shipping space and cost requirements.