03 11 13.00 10 STRUCTURAL CONCRETE FORMWORK.doc

SABER Solicitation FA2517-08-R-5002

SECTION 03 11 13.00 10

STRUCTURAL CONCRETE FORMWORK

PART 1 GENERAL

1.1 REFERENCES

1.1.1 The publications listed below form a part of this specification to the extent referenced. The publications are referred to in the text by the basic designation only. Unless otherwise noted, the latest published version and/or revision shall be used.

1.1.1.1 ACI INTERNATIONAL (ACI)

a. ACI 301

Specifications for Structural Concrete for Buildings

b. ACI 117 Standard Specifications for Tolerances for Concrete Construction and Materials

c. ACI 347

Guide to Formwork for Concrete

1.1.1.2 AMERICAN HARDBOARD ASSOCIATION (AHA)

a. AHA A135.4

Basic Hardboard

1.1.1.3 APA - THE ENGINEERED WOOD ASSOCIATION (APA)

a. APA PS 1

Voluntary Product Standard for Construction and Industrial Plywood

1.1.1.4 ASTM INTERNATIONAL (ASTM)

a. ASTM C 578

Standard Specification for Rigid, Cellular Polystyrene Thermal

Insulation

1.1.1.5 U.S. ARMY CORPS OF ENGINEERS

a. UFGS Unified Facilities Guide Specifications (Corrugated Fiberboard Void Forms)

1.2 SUBMITTALS

1.2.1 Government approval may be required on any of the following items. Items requiring submittals will be listed on the Submittal Register. Provide copies of all submittals per the requirements in Section 01 33 00, Submittal Procedures, or as listed on the Submittal Register.

1.2.1.1 SD-02 Shop Drawings

a. Formwork

(1) Drawings showing details of formwork, including dimensions and locations of joints, supports, studding and shoring, and sequence of form and shoring removal.

b. Corrugated Fiberboard Void Forms

(1) Void form shop drawings shall show method of providing specified void below all concrete construction shown on the drawings. Information shall include void thickness, layout of void forms, special forms required at drilled piers or pier caps and layout of special accessories. Details showing protection of void forms prior and during concrete placement and method of sealing void form joints and ends to prevent concrete intrusion into void space shall be provided.

1.2.1.2 SD-03 Product Data

a. Design

(1) Design analysis and calculations for form design and methodology used in the design.

b. Form Materials

(1) Manufacturer's data including literature describing form materials, accessories, and form releasing agents.

(2) Void form product data shall show the void form capacity for concrete placement and construction loads meets the specified loading. Product data shall also provide certification of void breakdown beginning no later than 14 days from date of concrete placement and complete breakdown occurring no later than six months from date of placement.

c. Form Releasing Agents

(1) Manufacturer's recommendation on method and rate of application of form releasing agents.

1.2.1.3 SD-04 Samples

a. Void Forms

(1) One sample unit of each type of fiberboard void form prior to installation of the voids.

1.2.1.4 SD-07 Certificates

a. Void Forms

(1) Certificates attesting that void forms conform to the specified requirements.

1.3 DESIGN

1.3.1 Formwork shall be designed in accordance with methodology of ACI 347 for anticipated loads, lateral pressures, and stresses. Forms shall be capable of producing a surface which meets the requirements of the class of finish specified in Section 03 30 00 CAST-IN-PLACE CONCRETE. Forms shall be capable of withstanding the pressures resulting from placement and vibration of concrete.

1.4 STORAGE AND HANDLING

1.4.1 Corrugated cardboard void forms shall be stored above ground level in a dry location. Void forms shall be kept dry until installed and overlaid with concrete.

PART 2 PRODUCTS

2.1 FORM MATERIALS

2.1.1 General

2.1.1.1 Provide concrete forms, accessories, shoring and bracing as required to accomplish cast-in-place concrete work.

2.1.1.2 Design and construct forms to provide resultant concrete that conforms to design with respect to shape, lines, finish and dimensions.

2.1.2 Forms For Class A and Class B Finish

2.1.2.1 Forms for Class A and Class B finished surfaces shall be plywood panels conforming to APA PS 1, Grade B-B concrete form panels, Class I or II. Other form materials or liners may be used provided the smoothness and appearance of concrete produced will be equivalent to that produced by the plywood concrete form panels. Forms for round columns shall be the prefabricated seamless type.

2.1.3 Forms For Class C Finish

2.1.3.1 Forms for Class C finished surfaces shall be shiplap lumber; plywood conforming to APA PS 1, Grade B-B concrete form panels, Class I or II; tempered concrete form hardboard conforming to AHA A135.4; other approved concrete form material; or steel, except that steel lining on wood sheathing shall not be used. Forms for round columns may have one vertical seam.

2.1.4 Forms For Class D Finish

2.1.4.1 Forms for Class D finished surfaces, except where concrete is placed against earth, shall be wood or steel or other approved concrete form material.

2.1.5 Retain-In-Place Metal Forms

2.1.5.1 Retain-in-place metal forms for concrete slabs and roofs shall be as specified in Section 05 30 00 STEEL DECKS.

2.1.6 Pan-Form Units

2.1.6.1 Pan-form units for one-way or two-way concrete joist and slab construction shall be factory-fabricated units of the approximate section indicated. Units shall consist of steel or molded fiberglass concrete form pans. Closure units shall be furnished as required.

2.1.7 Form Ties

2.1.7.1 Form ties shall be factory-fabricated metal ties, shall be of the removable or internal disconnecting or snap-off type, and shall be of a design that will not permit form deflection and will not spall concrete upon removal. Solid backing shall be provided for each tie. Except where removable tie rods are used, ties shall not leave holes in the concrete surface less than 1/4 inch nor more than 1 inch deep and not more than 1 inch in diameter. Removable tie rods shall be not more than 1-1/2 inches in diameter.

2.1.8 Form Releasing Agents

2.1.8.1 Form releasing agents shall be commercial formulations that will not bond with, stain or adversely affect concrete surfaces. Agents shall not impair subsequent treatment of concrete surfaces depending upon bond or adhesion nor impede the wetting of surfaces to be cured with water or curing compounds.

2.1.9 Fiber Voids

2.1.9.1 Fiber voids shall be the product of a reputable manufacturer regularly engaged in the commercial production of fiber voids. The voids shall be constructed of double faced, corrugated fiberboard. The corrugated fiberboard shall be fabricated of standard kraft paper liners, impregnated with paraffin, and laminated with moisture resistant adhesive, and shall have a board strength of 275 psi. Voids which are impregnated with paraffin after construction, in lieu of being constructed with paraffin impregnated fiberboard, are acceptable. Voids shall be designed to support not less than 1000 psf. To prevent separation during concrete placement fiber voids shall be assembled with steel or plastic banding at 4 feet on center maximum, or by adequate stapling or gluing as recommended by the manufacturer. Fiber voids placed under concrete slabs and that are 8 inches in depth may be heavy duty "waffle box" type, constructed of paraffin impregnated corrugated fiberboard.

2.2 FIBER VOID RETAINERS

2.2.1 Polystyrene Rigid Insulation

2.2.1.1 Polystyrene rigid insulation shall conform to ASTM C 578, Type V, VI, or VII, square edged. Size shall be 1-1/2 inches thick by 16 inches in height by 3 feet in length, unless otherwise indicated.

PART 3 EXECUTION

3.1 INSTALLATION

3.1.1 Formwork

3.1.1.1 Forms shall be mortar tight, properly aligned and adequately supported to produce concrete surfaces meeting the surface requirements specified in Section 03 30 00 CAST-IN-PLACE CONCRETE and conforming to construction tolerance given in TABLE 1. Where concrete surfaces are to have a Class A or Class B finish, joints in form panels shall be arranged as approved. Where forms for continuous surfaces are placed in successive units, the forms shall fit over the completed surface to obtain accurate alignment of the surface and to prevent leakage of mortar. Forms shall not be reused if there is any evidence of surface wear and tear or defects which would impair the quality of the surface. Surfaces of forms to be reused shall be cleaned of mortar from previous concreting and of all other 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

3.1.2.1 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 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 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

3.1.3.1 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

3.2.1 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

3.3.1 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

3.4.1 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 shall be removed from molds at the age of 24 hours and shall receive, insofar as possible, the same curing and protection as the structures they represent.

3.4.2 Tolerances for formed surfaces shall conform to ACI 117 – Standard Specifications for Tolerances for Concrete Construction and Materials except as modified in Table 1 below:

TABLE 1

TOLERANCES FOR FORMED SURFACES

3.4.2.1 Variations from the

In any 10 feet of plumb:

length ----------------- 1/4 inch

a. In the lines and

Maximum for entire surfaces of columns, length ------------------- 1 inch piers, walls and in arises

b. For exposed corner

In any 20 feet of columns, control-joint length ----------------- 1/4 inch grooves, and other

Maximum for entire conspicuous lines length------------------ 1/2 inch

3.4.2.2 Variation from the

In any 10 feet of level or from the length ------------------1/4 inch grades indicated

In any bay or in any 20 on the drawings:

feet of length---------- 3/8 inch

a. In slab soffits, Maximum for entire ceilings, beam soffits, length ----------------- 3/4 inch and in arises, measured before removal of supporting shores

b. In exposed lintels, In any bay or in any 20 feet of sills, parapets, length ----------- ----- 1/4 inch horizontal grooves, Maximum for entire and other conspicuous length------------------ 1/2 inch lines

3.4.2.3 Variation of the linear

In any 20 feet --------- 1/2 inch building lines from

Maximum -----------------1 inch established position in plan

3.4.2.4 Variation of distance

1/4 inch per 10 feet of distance, between walls, columns, but not more than 1/2 inch in any partitions one bay,and not more than 1 inch total variation

3.4.2.5 Variation in the

Minus ---------------- 1/4 inch sizes and locations

Plus ----------------- 1/2 inch of sleeves, floor openings, and wall opening

3.4.2.6 Variation in

Minus ----------------- 1/4 inch cross-sectional

Plus ------------------ 1/2 inch and beams and in the thickness of slabs and walls

3.4.2.7 Footings:

a. Variation of dimensions

Minus ------------------ 1/2 inch in plan

Plus ------------------- 2 inches when formed or plus 3 inches when placed against unformed excavation

b. Misplacement of

2 percent of the footing eccentricity width in the direction of misplacement but not more than

2 inches

c. Reduction in thickness

Minus ------------------ 5 percent of specified thickness

3.4.2.8 Variation in steps:

Riser ------------------ 1/8 inch

a. In a flight of stairs

Tread ------------------ 1/4 inch

b. In consecutive steps

Riser ------------------ 1/16 inch

Tread ------------------ 1/8 inch

End of Section 03 11 13.00 10

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