������������������������ SECTION 03121

 

������������� ARCHITECTURAL CONCRETE FORM LINERS

 

This section is based on products manufactured by Greenstreak Plastic Products Co., Inc. located at the following address:

���� 3400 Tree Court Industrial Boulevard

���� St. Louis, MO� 63122

���� Telephone:� (314) 225-9400 or (800) 325-9504.

���� Fax:� (314) 225-9854 or (800) 551-5145.

Although this guide specification is proprietary, it does include reference and performance standards.� GREENSTREAK concrete formwork accessories (form liners, rustication strips, control joint formers, chamfer strips, and shims) may be specified in this section or in another Division 3 Architectural Concrete section.� Joints in vertical and sloping walls may require waterstops to prevent water intrusion and staining of the architectural surface.� Form liners can be used for cast-in-place, precast, or tilt-up concrete construction.� This form liner section must be accompanied by an architectural concrete specification.� The specifier should edit this specification to suit the project's requirements.� Selection of the appropriate product for the project is the responsibility of the customer.

PART 1� GENERAL

 

1.1 SECTION INCLUDES

Delete any items below not required.

��� A.� Rigid plastic liners for texturing architectural concrete, form accessories, and release agents.

 

��� B.� Bearing shims for precast concrete.

 

��� C.� Bearing shims for tilt-up concrete.

 

1.2 RELATED SECTIONS

Delete any sections below not relevant to this project; add others as required.

��� A.� Section 03120 - Architectural Cast-In-Place Concrete Formwork.

 

��� B.� Section 03330 - Architectural Concrete.

 

��� C.� Section 03350 - Concrete Finishes.

 

��� D.� Section 03450 - Architectural Precast Concrete - Plant Cast.

 

��� E.� Section 03460 - Architectural Precast Concrete - Site Cast.

 

��� F.� Section 03470 - Tilt-Up Concrete.

 

1.3 SUBMITTALS

 

��� A.� Submit under provisions of Section 01300.

 

��� B.� Product Data:� Show compliance with the Contract Documents.� Include manufacturer's installation instructions.

 

��� C.� Shop Drawings:� Show form liner layout and termination details.� Indicate backup, rustication, reveal, and chamfer strip locations. Include jointing, form tie location and pattern of placement.� Architect/Engineer's review will be for aesthetic criteria.� Contractor is responsible for design of formwork and back-up of form liner for structural stability and sufficiency.

 

��� D.� Samples: 12 inch by 12 inch, of each pattern indicated.

 

��� E.� Certification by release agent manufacturer of compliance with local regulations controlling use of VOC's.

 

1.4 QUALITY ASSURANCE

Because this section accompanies at least one other architectural concrete section, the requirements of that section also apply to this work.� Enter the proper section number and title in the blank below.� For your reference, some of the standard requirements are included in the following reference documents:

 

ACI 117 - Standard Tolerances for Concrete Construction and Materials; American Concrete Institute.

 

ACI 301, Chapter 13 - Specifications for Structural Concrete; American Concrete Institute.

 

ACI 303R - Guide to Cast-in-Place Architectural Concrete; American Concrete Institute.

 

ACI 309, Chapter 7 - Recommended Practice for Consolidation of Concrete; American Concrete Institute.

 

ACI 347, Chapter 5.2 - Recommended Practice for Concrete Formwork; American Concrete Institute.

 

��� A.� Comply with applicable requirements of Section __________ for construction tolerances, formwork design, and placement and consolidation of concrete.

 

��� B.� Mockup:� Provide full scale mockup using actual specific materials, methods and workmanship to be used on the project.

������� 1.� Materials and methods include concrete mix (cement type, aggregate gradation, slump, water/cement ratios, plasticizers and additives), forming system (ties, liner, and formwork), form release agents, placement rate, form pressures, joint sealing, vibrating and stripping practices.

Delete all but one of the following 3 paragraphs.� Mock-up configuration may be indicated on drawings.� For small projects, mock-up may be incorporated as part of finished construction.� On large projects, a separate mock-up is recommended.

������� 2.� Select a convenient portion of the final work to construct as a mockup.� Accepted mockup may remain in the completed work.

������� 3.� Construct a separate mockup on-site.� Remove mockup after completion of work.

������� 4.� Mockup configuration:� As indicated on drawings.

������� 5.� Incorporate required formwork accesories and at least one vertical and one horizontal form liner joint.

������� 6.� On mockup, demonstrate patching and repair procedures for spalled concrete, and voids caused by honeycombing or bugholes.

������� 7.� Include one mockup in the Contract Sum.� Provide additional mockups as required.

������� 8.� Accepted mockup will be standard by which remaining work will be evaluated for technical and aesthetic quality.� Submit variations from mockup materials or techniques for approval prior to use.

������� 9.� Do not begin construction of formwork until mockup have been accepted.

 

1.5 DELIVERY, STORAGE AND HANDLING

 

��� A.� Cover form liners to protect from oil, dirt and ultraviolet exposure.

 

��� B.� Form liners will become more rigid and less impact resistant below 25 degrees F.� Handle with extra care at low ambient air temperature conditions.

 

 

PART 2� PRODUCTS

 

2.1 MANUFACTURER

 

��� A.� Provide products manufactured by Greenstreak Plastic Products Co., Inc., St. Louis, MO, 63122.� Phone: (314) 225‑9400 or (800) 325‑9504.� Fax: (314) 225‑9854 or (800) 551‑5145.

Greenstreak has more than 32 available patterns as shown in our Sweet's catalog.� All three grades of liner (Uni-Cast, Multi-Cast, and Dura-Cast) achieve the same results for the selected pattern.� The Contractor should select the grade based on his expected reuse, means and methods.� Many plastic liners with vertical ribs can be applied inside cylindrical column forms provided the rib spacing is an even multiple of the circle circumference.

2.2 MATERIALS

 

��� A.� Form Liners:� Thermoformed rigid polymer alloy sheets; Greenstreak "Uni-Cast", "Multi-Cast", or "Dura-Cast" at contractor's option.

������� 1.� Void-free surface that won't absorb moisture or cause discoloration of concrete.

Enter the pattern name or number in the blank.� If more than one pattern is used, it may be simpler to indicate the patterns on the drawings.

������� 2.� For textured finish concrete:� Provide special forming materials to produce form surfaces with face design, texture, arrangement, and configuration as shown on drawings;� Pattern:� _________

������� 3.� Provide liners that accomodate form pressures up to 1000 psf.� Comply with manufacturer's recommendations for support of large or deep patterns which may deform under pressure.

For ASTM test physical properties, see Technical Data table in GREENSTREAK'S Form Liner� CSI Spec-Data brochure.

������� 4.� Provide back-up strips as required to support liner from bow or deflection beyond allowable tolerances due to form pressures.

 

��� B.� Accessories:� Provide the following accessories manufactured by form liner manufacturer:

Delete accessories below if not required.� If more than one variation of each type of accessory is used, edit the specification to so indicate and be sure the contractor can tell where each is to be used, either by noting on the drawings or editing the specification.

������� 1.� Rustication strip with 1-1/2 inch face; reusable ABS plastic.

������� 2.� Rustication strip with 1-3/8 inch face; reusable ABS plastic.

������� 3.� Rustication strip with 2-1/8 inch face; reusable ABS plastic.

������� 4.� Radius chamfer: Continuous PVC strip with� 1/2 inch leg.

������� 5.� Radius chamfer: Continuous PVC strip with� 3/4 inch leg.

������� 6.� Radius chamfer: Continuous PVC strip with� 1 inch leg.

������� 7.� Radius chamfer: Continuous PVC strip with� 1-1/2 inch leg.

������� 8.� Triangle chamfer:� Continuous PVC strip with 1/2 inch leg.

������� 9.� Triangle chamfer:� Continuous PVC strip with 3/4 inch leg.

������� 10. Triangle chamfer:� Continuous PVC strip with 1 inch leg.

������� 11. Triangle chamfer:� Continuous PVC strip with 1-1/2 inch leg.

������� 12. Bearing shims:� High impact plastic; Rockwell Hardness M20, Compressive Strength 10,000psi (no fracture at 35,000 psi).

������� 13. Keyway:� "No.521"; 1-3/4 inch throat by 1-1/2 inch deep, reusable, impact resistant.

 

��� C.� Form Release Agent:� Provide release agent verified to be compatible with form liner material.� Barrier type release agents are not recommended for architectural concrete.

������� 1.� Non-staining, with no adverse affects to the concrete surface; compatible with concrete curing method.

������� 2.� Select release agent to maximize number of reuses of liner by reducing form stripping pressures and facilitating cleanup.

������� 3.� Release agent to have stated benefit of minimizing occurance of bugholes.

������� 4.� Complies with local regulations regarding the release of VOC's.

 

2.3 FORM DESIGN

 

��� A.� Design formwork to accomodate form pressures.

 

��� B.� Design tie spacing for tie strength, strength of form, concrete placing rates, allowable deflections, and architectural aesthetic requirements.

Each type of tie leaves a characteristic hole.� The architects/engineer should approve the tie intended for use.� Twisted wire ties should not be used.

��� C.� Provide minimum 1-1/2 inch face concrete cover over metallic, corrosive ties.

 

��� D.� Provide removable or snap-off metal or plastic form ties designed to prevent deflection of form and to prevent spalling concrete surfaces when removed.

 

��� E.� Choose tie strength to match form design, architectural spacing desired, and placing rates.

 

2.4 CONCRETE MIX DESIGN CONSIDERATIONS

 

��� A.� Design aggregate to not exceed form liner rib width to minimize risk of aggregate bridging and subsequent voids.

 

��� B.� While maintaining mix design strength and water/cement ratio, increase slump to 6 inches for workability on rough deep textured form liner patterns.� This is usually accomplished with use of superplasticizer.� Mineral admixtures and pozzolans increase workability but may adversely affect concrete appearance.

 

��� C.� Calcium chloride may corrode metal and darken and mottle the concrete or weaken the form liner and is not recommended for architectural concrete.

 

See ACI 303R for notes regarding Pigments and Pigmented Admixtures.

PART 3� EXECUTION

 

3.1 PREPARATION

 

��� A.� Before placing concrete, verify that lines and levels of formwork and form liner patterns are within allowable tolerances.� Make corrections as necessary.

 

��� B.� On multiple use liners, clean liner before each use.

 

��� C.� Apply form release agent at rate recommended by manufacturer.� Schedule concrete pour as soon as possible after application of release agent to avoid contamination by precipitation, dust, and debris.� Protect reinforcing seal from exposure to release agent.� Generally, apply thin film to minimize bugholes and staining.� Thick applications may not work as well as the manufacturer intended.

 

3.2 INSTALLATION

 

��� A.� Construct form liner and accessories to sizes, shapes, lines and dimensions shown.

 

��� B.� Provide openings, offsets, keyways, recesses, chamfers, blocking, and screeds as required to achieve architectural concrete textured finish.

 

��� C.� Provide solid butt form liner joints backed up to prevent deflection.

 

��� D.� Drill liner to accomodate ties.� If bar type snap ties are used, a sharpened and heated tie can create a tight fitting hole for insertion of ties.

 

��� E.� Anchor liner to form on centers not to exceed 18 inches.� Decrease anchor spacing as neccessary to accomodate form stripping pressures without damaging liner intended for multiple use.

 

��� F.� Form rustication lines located as indicated by nailing rustication strips to formwork within tolerances indicated by the ACI.

 

��� G.� Tightly form corners indicated to be chamfered with PVC chamfer strip.� Make chamfered corners smooth, solid, unbroken, continuous lines, which are uniformly straight.

 

��� H.� Nail keyway to formwork where indicated.

 

��� I.� Seal form liner joints, form liner accessories' joints, and tie holes to prevent cement paste from bleeding.� Bleed may reduce water/cement ratio thus locally darkening and discoloring concrete.� Bleed may also create fins which will spall upon stripping of formwork.

 

3.3 CONCRETE PLACEMENT

 

��� A.� Place concrete in manner required to avoid form exceeding 1000 psf.

ACI report 347R, titled "Guide to Formwork for Concrete," gives equations to calculate formwork pressure as a result of Placement Rate and Concrete Temperature.� GREENSTREAK's plastic form liners are designed to accomodate form pressures up to a maximum of 1000 psf without perceptable deformation.� Wide or deep form liner patterns always require backup strips as indicated in GSK literature to withstand 1000 psf form pressures.� Usually Type 1, 150pcf concrete with a 4 inch max slump, placed with normal internal vibration techniques to a maximum 4 foot depth, and placed at a rate of 4 to 6 feet per hour will not deform GREENSTREAK liners installed per GSK recommendations.� High lifts may exceed allowable placement rate and create potentially damaging form pressures.� Also, high lifts entrap air which results in bugholes and other potential surface defects.

��� B.� Keep concrete lifts less than 24 inches high.

 

��� C.� Thoroughly vibrate concrete to achieve good consolidation, and eliminate entrapped air thereby minimizing voids.� Internally vibrate through to previous lift to avoid lift lines.� Avoid contact with the form liner.

 

3.4 REUSING FORMLINER

 

��� A.� Replace split, or otherwise damaged liner which has the potential to fail on the subsequent pour or whose repair negatively impacts the aesthetics of the concrete finish.

 

3.5 TIE REMOVAL

 

��� A.� Remove ties as soon as possible after formwork has been stripped.� Treat tie ends to prevent staining concrete.

 

��� B.� To prevent spalling, removal of cones should be delayed until the concrete has adequate strength.� Treat tip of tie and dry tamp mortar into void.

See ACI 303R for notes on Treated Architectural Surfaces and Finishing and Final Cleanup (including blemish repair).Delete the following article if neither precast nor tilt-up concrete is applicable to this section.

3.6 LEVELING

 

��� A.� Level tilt-up and precast concrete walls with bearing shims before final grouting.� Use sufficient number of shim packs to not exceed allowable concrete stresses.

 

 

����������������������� Back to SPECDISK Table of Contents

---

sorabji.com > foundcrap > found floppies > specdisk