Tunnel-Form Construction in L.A. Debut : European Method of Pouring Concrete Units Held Cheaper, Faster
The 124-unit, five-story Japanese Retirement Home under construction at 325 S. Boyle Ave. in Boyle Heights looks like any other reinforced concrete structure.
Looks are deceiving in this case: The project, scheduled for completion in February, is the first in Los Angeles to be constructed using techniques that have been in wide use in Europe for almost two decades.
The walls and ceiling of each unit are poured at the same time, using tunnel forms supplied by the Canoga Park-based American subsidiary of Machinefabriek Aarding, a company headquartered in Nunspeet, the Netherlands.
Faster, Cheaper
For buildings of 60,000 square feet or larger, tunnel-form construction is at least 20% faster and 20% less expensive than methods that use plywood or prefabricated metal forms, according to Jacque S. Schwarz, managing director of Aarding Forms Inc., Canoga Park.
Europe is in the forefront of reinforced concrete technology, and Aarding is a major force in tunnel shutterings, as the squared-off, U-shaped forms are called in Europe, according to Ivan Warren, vice president of Aarding Forms Inc.
California may have the reputation for innovation, but the construction industry here--more so than in other parts of the nation--is relatively slow to accept new techniques, he added.
“Tunnel forming has been widely used in Florida, in other East Coast cities and in the Midwest, where it is particularly adaptable to cold weather concrete pouring,” Warren said.
The only other serious stateside competitor to Aarding is Outinord, a French firm with U.S. operations in Florida. Both companies are represented in Fillmore Center, a mixed-used residential/retail development under construction in San Francisco’s Western Addition, according to Schwarz. Aarding’s forms were used in the M-1 tower in the San Francisco project, while the competitor’s forms are being used in the T-1 tower, he said.
There are other tunnel form manufacturers in Europe, especially West Germany, where concrete construction is widespread, Schwarz said.
“The building must be designed to take into account the repetitive nature of tunnel forming, which lends itself to structures like hotels, retirement complexes and apartment buildings with different spans, but which repeat themselves in a construction cycle,” he said.
California applications of Aarding forms include Ramada Inns in Cypress and Sunnyvale, and a Days Inn in La Palma, Warren said. The firm’s products, which are available for sale or rent, have also been used in a 296-unit Hemet retirement complex scheduled for completion in February, and a Radisson Suites Hotel under construction in Rancho Bernardo.
Because as many as six units can be poured during a typical working day using the Aarding tunnel forming system, the cost of a concrete building--with all its advantages of fire and termite resistance and soundproofing--is now competitive with that of the Type 5 wood-framed construction so common in California, Warren said.
He credits Yosh Nasu, vice president of Kajima Engineering & Construction Co. with initiating the use of tunnel forms on the Boyle Heights project. The architect is Sata/Kikuchi, Pasadena, and the structural engineering firm is Kamei/Wheeler & Gray, Los Angeles. The concrete subcontractor is Sunseri Construction Co., Chico.
Hideaki Fujiwara, project manager for Kajima, said in an interview at the job site that tunnel forming is an ideal method to build projects with repetitive element, such as the retirement complex where most of the suites are similar. Also at the job site, John Torres, superintendent of the construction division of Kajima, said the work went smoothly--especially since it was the first time Kajima had employed the tunnel form method for pouring concrete.
