Using hand set forms for concrete walls is faster than building wooden formwork from scratch. However, this still can take significant time and contractors always are looking for ways to streamline work to save money. For that reason, manufacturers of engineered form systems have focused their efforts on making their systems faster and easier to use.
Clamps, pins, and wedges are some of the methods used to quickly erect and disassemble hand set forms. A quick review of some of the various systems can help you decide what will work best for your project.
Key connecting system
Canada-based Aluma Systems uses a key connecting system that is simple in design and easy to use. Each slotted key is identical; one key is slipped through the panel side rails and another key slides through a slot in the first key. The only tool required is a hammer, says Allan Becker, Aluma's product and technical services manager.
“The fact that the keys are all the same means that you don't have to find the right piece of hardware to use; any key will do,” Becker says. The key system also is used to locate the tie rods between the two panel faces, which means all the tie rods are located at the panel edges.
Germany's Meva Formwork Systems, Peri Formwork, and Doka each use a clamping system for connecting formwork panels. The Meva Assembly Lock system, consisting of a clamp and a wedge pin, is used for both its Imperial and MevaLite forming systems. The wedge pin is locked into the clamp with a single strike from a hammer, and offers a strong connection that is safe to use with vibration. A groove on the inside edge of the company's many size panels allows the lock to be placed anywhere on the panel edge. “There are no holes to line up like other systems,” says Meva's engineering manager Steffen Pippig.
Peri's BFD Alignment Coupler is the one connector for all its wall-forming systems. It fastens, aligns, and tightens the formwork in one operation, and requires only a hammer. Doka's Framax multifunction clamp has an adjustment range up to 6 inches and can easily incorporate wood fillers. The Alisply connecting clamp, from Spain's Alsina Formwork, uses a simple lever action and requires no tools at all.
A major benefit of these clamp-style systems is that they can be quickly attached with a limited number of tools needed to put them together. Fewer tools mean less to carry and faster work. The clamps, though, weigh several pounds each, so when putting the panels together, you should have a bucket of them handy.
In the United States, Symons uses multiple types of connecting systems for its formwork systems. For example, the Rasto system, with its modular design for hand set or gang form applications, uses a clamp that slides closed with a wedge. The Steel Ply system, for hand set or gang form applications in commercial or residential structures, uses a slotted wedge bolt that fits through the panel side rails. The Symons Silver all-aluminum forms come with a pin and wedge system. The curved wedge slides through a slotted pin that connects the panel side rails.
Kansas City-based Western Forms also uses a pin and wedge. The company has a pin lock that attaches to the form even when not in use, so there is no risk of losing it.
Each system has its merits and can significantly reduce the time needed to erect formwork. But each one still requires some practice. Remember, buying a forming system weds you to that system for years to come, so you should be comfortable with how it operates. Take the time to speak with manufacturers about the connecting systems before purchasing.