FORM MATERIALS

We finished Chapt. 1 & 2and we are reviewing Chapt. 3 & 4!!!

Chapter One- Introduction to FormingChapter Two- General Objectives in Formwork BuildingChapter Three-Overall Planning for FormworkChapter Four-Materials, Accessories, Proprietary Products

Book Overview

What are the objectives of any form design?

The form design must provide,

SAFETY

THE BEST QUALITY

ECONOMICS(PLANNING & COST)

What types of forms are used in formwork?

1. Prefab Forms2. Pans and Domes for concrete joist3.Void and Duct Forms4.Column Forms5. Stay-in-place forms

What types of shoring is used in formwork?

1.Shoring Scaffolding2.Vertical Shores3.Scaffold-Type Shoring4.Horizontal Shoring

What materials and accessories are used in formwork?

1. Lumber 2. Steel 3.Aluminum 4. Glass-Fiber-Reinforced Plastics(4-16) 5.Fabric Forms(4-18) 6. Form Lining Materials(4-20) 7.Fasteners (4-25 to 4-33) 8. Ties(4-34) 9.Anchors(4-36) 10 Hangers(4-37) 11. Jacks(4-37) 12. Spreaders & Spacers(for rebars) 4-38 13. Steel Strapping & Column Clamps (4-39&40) 14. Prefab Forms (4-41) video 15. Pans and Domes (4-45)

1. Lumber (overview)

• Choice of lumber is affected by the availability and cost• Lumber is required to be straight, structurallysound, and partially seasoned (19-25%)Note: Do not use old lumber with new. If lumber is too dry it will swell under moistconditons, and if too moist it will shrink in dryconditions.• Commonly used lumber is the DF-L, DF-S,Spruce-Pine Fir, and Hem-Fir• Dressed lumber is used for formwork, and the rough sawn boards are used in bracing andshoring.(formwork used here means the members that are used to shape the concrete)

1. cont. Lumber (overview)• Dressed lumber is surfaced lumber (i.e. S1SE,S1S2E,S4S,etc)Refer to P. 4-4 for wood propertiesalso P.4-6 for wood stresses, note thereis no Ft (tension parallel to the grain) • Note adjustment factors as noted on P. 4-6 & 4-7. No size adjustment is required for construction and standard grade lumber• Engineered Wood Products are

becoming more common due to dwindling supplies of sawn lumber and in many cases can give us better strength characteristics. (i.e. glulam, LVL, etc.)

1. cont. Lumber(Plywood/Sheathing)

• Plywood is common in most systems as sheathing• Sheathing is used in direct contact with concrete. It is primarily : plywood, steel,aluminum, etc.

It does not include liner panels or othersurfacing directly contacting concrete

Why do we need to protect plywood?• Concrete has water • Concrete is an alkaline• Concrete has abrasive constituents• Concrete is heavy & a fluid

How do we protect plywood?

1. cont. Lumber(Plywood/Sheathing)

• We bond interior with water-resistant glue and exterior with water-proof glue

• exterior plywood is required for reuse

What is overlaid plywood?• Overlaid plywood is exterior plywood

with additional resin-impregnated fiber faces permanently fused under heat and pressure

It is either High Density Overlaid (HDO) or Medium Density Overlaid (MDO)Overlays provide high strength, light wt., dimensional stability, rock resistance

What is overlaid plywood?

• High Density Overlaid (HDO) P. 4-12Overlays provide high strength, light wt., dimensional stability, rock resistance, hardand smooth• Resin Overlay- add ability to

• Withstand severe exposure w/o further finishing

• Resists abrasion• Prevent water penetration• Prevent deterioration from chemicals

&solvents• Overlay thickness -.012 w/60#per

1000sf of panel surface• Ply Bonding - 100% water proof glue• Construction- Inner plies: C or C

plugged and face is B or better• Maximum reuse (200 pours)

What is overlaid plywood? (cont)

• Medium Density Overlaid (MDO) P. 4-12Sanded two sides, oiled at will • Needs good quality edge sealer before

1st pour (10 to 20 reuses)• Not recommended for forms but can be

used.• Recommended use of a release agent

• Other overlays • glass-fiber-reinforced plastic• formica• epoxy resin

• Non Overlaid Plywood• Classification for veneer is A-D• Classification for Panel Strength is

Group 1 to 5(i.e DF-L is Strongest andin group#1)

2.& 3. Steel/Aluminum Pretty much used the same way as wood but allows for greater spans or heavier loads (i.e. channels,angles, I-beams, etc.)

Aluminum is lighter weight and can produce forming units larger than other materials can manage.(i.e can be 50% wider than plywood, and have the same weight)

For section 4-15 on the slide see video and follow textbook.

*4. Glass-Fiber-Reinforced Plastics(fig.4-53)

*5.Fabric Forms(fig. 4-15)

*6. Form Lining Materials(fig 4-17)

7.Fasteners (4-25 to 4-33)

*8. Ties(4-34)

9.Anchors(4-36)

10 Hangers(4-37)

*11. Jacks(fig 4-35)

*12. Spreaders & Spacers(for rebars) 4-38

13. Steel Strapping & Column Clamps (4-39&40)

14. Prefab Forms (4-41)

15. Pans and Domes (4-45)