Hamilton Form, Ltd.
7009 Midway Road
Fort Worth, TX 76118

Phone: 817 590-2111
Fax: 817 595-1110
sales@hamiltonform.com

PCI NPCA CPCI

Frequently Asked Questions

How does pretensioning affect my forms?

Self-stressing forms are designed to resist both the hydrostatic forces of concrete, and the compressive forces applied to the form by prestressing. Our engineers design forms based on the amount and placement of prestressing force based on criteria outlined by the customer. The first rule in pretensioning is: Never Exceed the Capacity of the Form.

When prestressing, it is critical to balance the prestressing load being applied to the form. This helps protect your form from eccentric loading that can cause serious form damage. Balance the load being applied to the form by paying attention to the following:

  1. Ease the form into tension by symmetrically loading the form. Move from side to side and up and down so that the load is being evenly applied.
  2. In general, you should tension the lower strands first, then, move in an ascending pattern upward.
  3. When tensioning a double tee, tension a few strand in one stem, then move to the other stem, tensioning this stem with the same designated number of strand. Moving side to side in an upward manner will ease the form into full loading and also allow for free movement of the form as tensioning is completed.
  4. When tensioning a dual, triple or quad pile form, use the same logic. Partially tension one side, then, move side to side and upward to reach full loading.
  5. Never pour one side of a dual form and not the other without paying proper attention to how the form is being stressed. If you need to cast only one side of a dual cavity piling form, you may need to at least partially stress the side not being used to help balance the loading on the form.
  6. If you have a triple pile form and need to pour only one cavity, use the center cavity not one of the side cavities so that you do not eccentrically load your form.

If you have any questions or concerns, consult with your plant engineer, or call Hamilton Form at 817 590-2111.