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Flashcards in Precast Concrete Deck (16)
1

precast beam shapes

usually rectangular, T-shaped, or L-shaped.

2

advantage of T and L shaped beams

floor flush w/ top of beam (min. total depth)

3

very efficient, widely used,
topping slab poured, cover joints and level floor.

single T and double T sections

4

typ. rec. shape w welding plates top+bottom.
cast w haunches (shoulders)

Precast Columns

5

in addition to T-section as floor/roof,
simple reinforced slabs used.

Floor and Roof Panels

6

Floor and Roof Panels: solid slab =

light loads + short spans

7

Floor and Roof Panels: hollow, cored slab =

heavier load + longer span
increased depth, while min weight.

8

Floor and Roof Panels: hollow, cored slab can be up to this length

up to 36ft long
6-12” thick, 4’ wide

9

multistory technique,
entire floor sections are cast on ground,
one on top of other,
around pre-erected columns.
bond breaker between successive pours.
lifted into place (jacks attached to columns)
connected to columns w weld plates.
typ min formwork and construction time.

Lift slab construction

10

Wall Panels typ. dims

typ 5-8” thick, long enough to span columns or beams.

11

$ savings @ wall panels

if panels span beams, > $ savings in multistory by panels spanning 2 floors.

12

can be cast horizontally right on floor slab using a bond breaker

tilt-up

13

sheet of plastic or liquid solution (better finish)

bond breaker

14

members have internal stresses applied before subject to service loads.
compressive forces where member would be in tension.
more efficient + economical section,
reduces cracking + deflection,
increases shear strength,
longer spans/ greater loads.

Precast, Prestressed Concrete

15

precasting plant.
high-strength stranded cable/wire draped in forms, tensile force applied.
once cured, cables are cut,
compressive forces transferred to concrete through bond between cable/conc.

Pretensioning

16

hollow sleeves or conduits placed in forms on site.
high-strength steel tendons,
stressed w hydraulic jacks after cure,
ends secured to conc.
in bonded construction: sleeves removed, grout forced between tendons/conc.

Post-tensioning