A Closer Look At FORMWORK: Procedure for Erection of Forms for Footings.

As the title would suggest, this is another post to tell us more on Formwork.

Just before I go into that, in response to the preceeding post on Formwork, I recieved some funny comments via Facebook. Ademola, an Arsenal FC fan said his team needs formwork and he suggested I recommend the highest diameter of reinforcement bars for the team.  I couldn’t stop laughing but the truth is he want his team to come out clean. On the international scene too, drama happened, while some fans called for Arsene’s head some maintained the phrase “In Arsene Wenger we trust”. Either way am not to take side but I would like say that these responses reaffirms the need for good forms.

In building construction, certain components are derived by placing concrete in formworks. More so, a building may have all its components precast including the walls.

Procedure for Erection of Forms for Footings Figure 8-3 will be used to illustrate and describe the step-by-step procedure for erecting wall forms using these panels. At the time the wall footing was poured, short pieces of lumber were set in the concrete flush with the top surface of the footing at about 4-ft intervals to serve as nailer inserts. The procedure in erecting the forms is as follows:

1. Place two rows of plywood-faced 4 × 4 S4S lumber, with the inner faces separated by the thickness of the wall, along the footing as sole plates. The top edge of the plywood facing extends¹⁄8 in. above the top of each plate. Toe-nail the plates to the nailer inserts in the footing.

2. Place through-wall button-end spreader ties at the desired spacing across the sole plates. Either hit each tie with a hammer to embed it in the projecting edge of the plywood or precut notches in the edge of the plywood to receive the ties.

3. Set the lower tier of form panels on the sole plates extending along the footing, with the ends of the panels butting against each other. Fasten the end studs of adjacent panels together, using bolts, short form ties, or double-headed nails. Then nail the lower plate of each form panel to the 4- by 4-in. sill plate, and wedge-clamp the form ties.

4. Space form ties along the top surface of the tier panels.

5. Set another tier of form panels on top of the lower tier. Fasten the ends of the panels together, as described previously, and then nail the bottom plate of the second tier to the top plate of the first tier. Then wedge-clamp the second row of form ties.

6. Install form spacers across the top tier of forms, using 1 × 4 wood boards, metal straps, U-shaped steel rods set through prebored holes in the top plate, or some other suitable method. The U-shaped rods can be inserted and removed quickly and should have a very long life.

7. Install vertical double 2 × 4 wood strongbacks along the inside wall, at 8-ft spacings at the end junctures of panels, using through-wall form ties to hold them in place.

8. As the forms are aligned, attach a brace near the top of each strongback and to a stake set in the ground. Erecting and stripping the forms can proceed at a very rapid rate after the form crew becomes familiar with this procedure.

Excerpt from:

Formwork for Concrete Structures by
Robert L. Peurifoy Late Consulting Engineer Austin, Texas Garold D. Oberlender Professor Emeritus Oklahoma State University

“docendo discitur”: It is learned by teaching.

A Peep into FORMWORK

Another EPL season starts this weekend. Not a lot of drama have happened yet in the transfer market though the top three sides have changed managers. However, these new managers would obviously play the game the best way they know could win the title. In the light of this, they have warned all their players to get into form else they risk their first team appearances. ‘ Whoever fails to get into good shape will rot on the bench’ says one of the new managers. While others are busy grudging and feeling very bad under this condition of their new manager, Concrete, an indispensable player for Building FC sees this as a call for greater Form. Though indispensable, he’s not ready to give any other player a chance to play his role. More so, everyone loves to show off what they’ve got especially under a new manager.

Welcome, this is my first post on this blog and I hope you enjoy it. My little story up there is an introduction which is aimed at setting our minds to what we’d be discussing today, ‘Formwork’. There are several definitions to ‘Formwork’ by different authors but I wouldn’t want to be messy here, I’d just go ahead and give one which I strongly agree to. The American Heritage Dictionary for English Language (4th edition) defines Formwork as “The structure of boards that make up a form for pouring concrete in construction” As concise as this definition is, there is more to formwork than would be discussed here.

A traditional timber formwork for column

Functional requirements of Formwork

1. It should be lightweight without compromising its required strength
2. Formwork components must fit closely enough at joints to resist concrete outflow.
3. Formwork surface must be well prepared to give a neat finish to resulting structural component
4. It must be strong enough to carry imposed dead and live loads of concrete and the people working on it.
5. It must be rigid and tolerant.
6. It must be built to give precise dimensions of structural component.
7. Formwork should be made to make striking/stripping practically uncomplicated
8. Being lightweight, it should be easy to move it around for reuse.

Materials used for Formwork

1. Timber
2. Steel
3. Plywood
4. Aluminium
5. Plastic
6. Fabric
7. Fiberglass
8. Glass Reinforced Plastic
9. Masonry
10. Concrete

Selection Considerations

1. Cost efficiency
2. Efficacy of material to specific task
3. Level of finish desired
4. Availability of technical personnel
5. Number of repeat use intended
6. Environmental factors

“if you want to come out clean then go in with a great form”