FUNCTION

shape concrete slurry

support concrete during curing

support reinforcement

temporary working surface

retain water for hydration process

temporary in nature

FORM DESIGN

negative shape of concrete

corners

no reentrant corners

avoid 90 degree corner

45 corners preferred 1/2" - 1"

rounded corners 1/2" radius

non-adhesive coated surface

form-release compound

oil

wax

plastic

FORM WORK

Form Type:

re-useable

metal

plywood

custom form

wood

cardboard

lost form

metal deck

Styrofoam

fill

tapered form to slip off

no damage to concrete

no damage to form

Appearance

impression

texture

pattern

Structural

joints

Ties

Screw ties

plastic cap

patched

Snap ties

left exposed

Structural

145 pcf unreinforced concrete

150 pcf reinforced concrete

maintain position

maintain shape (deflection)

Work surface

Construction equipment

Function:

Tension

skin reinforcement

for beams over 3' deep

Shear

stirrups

Positioning

continuous cage

Concrete Coverage:

Fire Protection

Corrosion

Exposure

Earth 3"

Exterior 2"

Interior 1.5"

Interior Shells 0.5"

see Leet p. 105 Table 3.3

Spacers:

bolsters - continuous length

chairs - individual bars

plastic

metal - plastic coded

metal - plastic capped

Spacing between Bars:

Coarse aggregate to pass through

>= 1" min.

>= of rebar

Upper bars directly over lower bars

Standards:

bars

bar # = in 1/8"

welded wire fabric

hooks

tie hooks

end hooks

stirrups

steel adheres to concrete

epoxy coated for special applications

Mixture

water

cement

aggregates

fine aggregates

coarse aggregates

admixtures

Mixing:

transit-mixed

mixing drum

surface mixed with shovel

1 shovel cement (94-lb. bag)

2 shovels of sand

3 shovels of gravel

enough water to mix it

Quality Check:

Slump test

cone

12" tall

6" top

12" bottom

5/8" 24" long taping rod

slump measured in inches

7-day break

standard test cylinder

60 - 70% of final strength

up to 90% with high-earlystrength

Portland cement III & admixtures

28-day break

final strength

test cylinder

6"

12" high

w/c ratio - the less water the better

balanced aggregates

cement type, admixtures, curing

LECTURES

To Home Page

Timetable

Prof. Dr. Hermann Gruenwald

(mail comments to: HGRUENWALD@ou.edu)

College of Architecture

The University of Oklahoma