foreign material before reuse. Form ties that are to be completely
withdrawn shall be coated with a nonstaining bond breaker.
3.1.2
Fiber Voids
Voids shall be placed on a smooth firm dry bed of suitable material, to
avoid being displaced vertically, and shall be set tight, with no buckled
cartons, in order that horizontal displacement cannot take place. Each
section of void shall have its ends sealed by dipping in paraffin, with any
additional cutting of voids at the jobsite to be field dipped in the same
type of sealer, unless liners and flutes are completely impregnated with
paraffin. Prior to placing reinforcement, the entire formed area for slabs
shall be covered with a 1.22 x 2.44 m 4 x 8 feet minimum flat sheets of
fiber void corrugated fiberboard. Joints shall be sealed with a moisture
resistant tape having a minimum width of 75 mm 3 inches. If voids are
destroyed or damaged and are not capable of supporting the design load,
they shall be replaced prior to placing of concrete.
3.1.3
Fiber Void Retainers
Fiber void retainers shall be installed, continuously, on both sides of
fiber voids placed under grade beams in order to retain the cavity after
the fiber voids biodegrade.
3.2
CHAMFERING
Except as otherwise shown, external corners that will be exposed shall be
chamfered, beveled, or rounded by moldings placed in the forms.
3.3
COATING
Forms for Class A and Class B finished surfaces shall be coated with a form
releasing agent before the form or reinforcement is placed in final
position. The coating shall be used as recommended in the manufacturer's
printed or written instructions. Forms for Class C and D finished surfaces
may be wet with water in lieu of coating immediately before placing
concrete, except that in cold weather with probable freezing temperatures,
coating shall be mandatory. Surplus coating on form surfaces and coating
on reinforcing steel and construction joints shall be removed before
placing concrete.
3.4
REMOVAL OF FORMS
Forms shall be removed preventing injury to the concrete and ensuring the
complete safety of the structure. Formwork for columns, walls, side of
beams and other parts not supporting the weight of concrete may be removed
when the concrete has attained sufficient strength to resist damage from
the removal operation but not before at least 24 hours has elapsed since
concrete placement. Supporting forms and shores shall not be removed from
beams, floors and walls until the structural units are strong enough to
carry their own weight and any other construction or natural loads.
Supporting forms or shores shall not be removed before the concrete
strength has reached 70 percent of design strength, as determined by field
cured cylinders or other approved methods. This strength shall be
demonstrated by job-cured test specimens, and by a structural analysis
considering the proposed loads in relation to these test strengths and the
strength of forming and shoring system. The job-cured test specimens for
form removal purposes shall be provided in numbers as directed and shall be
in addition to those required for concrete quality control. The specimens
SECTION 03100A
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