ARCHIVED – CCMC v4n3-6

Volume 4, Number 3, Spring/Summer 1999

Archived Content

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CCMC evaluates bell-shaped foundation forms

CCMC's role is to help Canadian manufacturers gain both national and international market acceptance of their construction products by providing sound technical evaluations. A recent evaluation of an innovative foundation form for concrete column footings shows how this process works.

Since this product was not covered explicitly by current building codes, CCMC was approached to develop technical requirements for this type of foundation form. Rather than using the conventional method of building forms, with their inherent costs of wood and steel, and tools and labour, the new product comprises an engineered cone-shaped form made of recycled lightweight high-density polyethylene, which comes in a variety of shapes and sizes (see Figure). It is used in conjunction with a traditional column forming tube, which is placed around the top opening of the form.

column
COLUMN FOOTING FORM

CCMC's role was to determine whether the product could perform as it had been promoted. The evaluation required the units to be installed as recommended by the manufacturer and to remain in place during and after being filled with concrete. In accordance with the testing criteria established by CCMC:

  1. the top of the attached forming tube had to remain in place to receive the columns, beams and joists;
  2. the sloped surfaces of the form had to withstand the placement of backfill before the concrete was poured without collapsing or bending excessively; and
  3. the development of entrapped air pockets in the form was not permitted.

Field tests were necessary to confirm all of the above criteria.

For this type of forming system, concrete is required to be designed, mixed, placed, cured and tested in accordance with the standard, CAN3-A438-M, Concrete Construction for Housing and Small Buildings. CCMC's technical guide addresses other aspects of the design of such systems - specifically, allowable loads on forms for different types of soil, ranging from soft clay to sound bedrock. The final evaluation reports for this type of product will indicate the allowable loads for each footing form and the maximum spacing for both exterior and interior footings.

The innovative column footing form described above was evaluated against the technical requirements developed by CCMC and found to meet these requirements. It is now listed in the CCMC Registry of Product Evaluations, under "BIGFOOT SYSTEMS(tm)", CCMC 12839-R. The manufacturer of this product has informed CCMC that he has gained acceptance from regulatory bodies in the United States and Japan, which he attributes to the CCMC evaluation.

Specific questions can be directed to Mr. Ron Waters at (613) 993-6602, fax (613) 952-0268, or e-mail ron.waters@nrc-cnrc.gc.ca

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