1. What have we accomplished? STRENGTH OF MATERIALS
FORM NOMENCLATURE AND SAFETY
What have we accomplished?
STRENGTH OF MATERIALS
TIMBER DESIGN
SOIL MECHANICS
STEEL DESIGN
Where do we go from here?
Book Overview
Chapter One- Introduction to Forming
Chapter Two- General Objectives in
Formwork Building
Chapter Three-Overall Planning for
Formwork
Chapter Four-Materials, Accessories,
Proprietary Products
Chapter Five -Load and Pressures
Chapter Six- Form Design

2. Introduction to Forming
What is forming and formwork?
Formwork is the total system of support
for placed concrete.
It is a major cost of a concrete structure
(it accounts for as much as 60% of the cost)
What is its purpose?
to safely support the reinforced concrete in
its plastic state until it has reached adequate
strength
What are the objectives of any form design?
the form design must provide the best quality,
safety and at also be economical

3. Introduction to Forming
the best quality entails:
1. alignment to adjacent surfaces
2. resistance to excessive deflections
3. a good surface finish
4. structural integrity to withstand service
loads
5. its ability to use standard materials
6. dimensional consistency or its repetitive
members
Note: Safety and Economics will be covered
in more detail later on

4. Introduction to Forming
What kind of nomenclature or terminology
is associated with forming?
Form ties- installed through the forms to
resist the bursting pressure exerted by the
concrete. ( has a clamping device at each
end for attachment to and support of the
wales

5. Introduction to Forming
Beam- horizontal structural load bearing
member
Braces- fastened to one side of the forms to
prevent shifting when concrete is placed
Formwork- the total system of support for
freshly placed or partially cured concrete.
This includes the mold or sheathing that
contacts the concrete as well as supporting
members

6. Introduction to Forming
What kind of nomenclature or terminology
is associated with forming?
joists- horizontal members which directly
support sheathing
reshoring- the construction operation in which
the original shoring is adjusted or replaced to
support partially cured concrete and other
imposed loads
Sheathing - the material forming the contact
face of forms and providing the resistance to
the pressure of the freshly placed concrete
Shoring(falsework)-the elements used ,
excluding the formwork, to support fresh
concrete and/or structural members during
construction(i.e. vertical posts, lateral bracing,
etc.)

7. Introduction to Forming What kind of nomenclature or terminology
is associated with forming?
Sill(Mud Sill)-a member, usually wood,
designed to distribute the vertical shoring loads
to the ground or the slab below.
Stringer(Ledgers)- horizontal structural
members which directly support joists

8. Introduction to Forming
Studs- members to which the vertical sheathing
is attached and provide support for it, it is
installed vertically
Wales(Walers)-installed perpendicular to the
studs in order to support the studs, to hold
the studs in position, to ensure good alignment
for the forms and to recieve the form ties

9. Introduction to Forming What kind of nomenclature or terminology
is associated with forming?
Cleat-small board used to connect formwork
members or used as a brace
Base Plate- a device used between post, leg
or screw and foundation to distribute the
vertical load(mudsill)

10. Introduction to Forming
Strongbacks- installed perpendicular to wales
to provide additional strength and rigidity to
high forms
Batten(Batten Strip)-a narrow strip of wood
placed over the vertical joint of sheathing or
paneling, or used to hold several boards
together

11. Introduction to Forming
What kind of nomenclature or terminology
is associated with forming?
Sources:
Glossary refer to Appendix page A-3
Pictures with spec A-16 to A-20
Pictures of Vertical shoring 4-51
Pictures of Ties 12-19

12. Introduction to Forming
What are the safety issues involving form
design?
Causes for Formwork Failures:
1.Improper or inadequate shoring
2. Inadequate bracing of members
3. Lack of control of rate of conc. placement
4.Improper vibration or consolidation of conc.
5.Improper or inadequate connections
6. Improper or inadequate bearing details
7.Premature stripping of formwork
8.Errors in placement of reshoring
9.Improper, or lack of, design of formwork
10. Inadequate strength of form material
11. Failure to follow codes and standards
12. Modifications of vendor-supplied equip.
13. Negligence of workers or supervisors

13. Introduction to Forming
What are the safety issues involving form
design?
Examples Formwork Failures:
1.Improper or inadequate shoring
i.e wrong size(too small to carry the load
or too long and buckles)
2. Inadequate bracing of members
lack of cross or horizontal bracing
the cross bracing is preferred
3. Lack of control of rate of conc. placement
This causes excessive pressures
high discharge point causes impact loads
in cold conditions the setting rate is retarded
4.Improper vibration or consolidation of conc.
internal problems- impact loads on members
external problems-liquefaction occurs, and
vertical sleaves vibrate out of plumb alignment

14. Introduction to Forming
What are the safety issues involving form
design?
Examples Formwork Failures:
5.Improper or inadequate connections
Fasteners suitability (threaded vs. nails)
or inadequate number of nails
6. Improper or inadequate bearing details
Shores placed directly on ground w/o plate
uncompacted or suitable soil conditions
insufficient thickness to bridge gaps
7.Premature stripping of formwork
inadequate time duration to set or cure
8.Errors in placement of reshoring
improper locations (introduce secondary
stresses)
insufficient quantity provided

15. Introduction to Forming
What are the safety issues involving form
design?
Examples Formwork Failures:
9.Improper, or lack of, design of formwork
lack of basic design principles
use of too high allow stress values
insufficient loading consideration(i.e impact)
improper loading value(i.e. conc thickness)
10. Inadequate strength of form material
i.e Construction grade vs. structural grade
damage due to use
insufficient & improper ties to multiple
members
11. Failure to follow codes and standards
Failure to follow the ACI-concrete
NDS-wood
AISC-steel

16. Introduction to Forming
What are the safety issues involving form
design?
Examples Formwork Failures:
12. Modifications of vendor-supplied equip.
proprietary equipment- misuse
13. Negligence of workers or supervisors
untrained workers
poor supervision

17. Introduction to Forming
Inspection Stages recommended by ACI:
1. Preliminary Inspection is after the forms
are built and prior to the oiling or re-bar
placement
2. Semi-Final Inspection is prior to final
cleanup
3. Final Inspection is immediately before
concreting to make sure surface is clean and
oiled
Recommendation:
During the concrete pouring listen to forms
for cracking and popping noise
look at all portions and check for
displacement of elements and vertical
misalignment

18. Introduction to Forming
What are the safety issues involving form
design?
See Case Studies in 2-4 to 2-8