Level 3 C4 Precast/Tilt Up Flashcards
One advantage of pre cast units manufactured in a plant is _______ control
quality
The use of ____ _____ can reduce the rebar and concrete volume of a precast unit
stress cables
The decision to use a mobile or existing casting yard is determined by the _____ and ______ of the units.
quantity and design
On the jobsite, precast units can be secured to each other by using _____ and/ or weld plates.
dowels
What is a pre cast pile?
a long structural member that penetrates deep into soil.
What is a pile shoe?
It covers the tip of a precast concrete pile and protects it from damage while it is being driven into the ground
_____ _____ are screwed in to protect the insert against being filled with concrete during the pour.
Plastic caps
Pretensioning occurs before or after the concrete is poured?
before
Why must prestressed cables be clean?
So that the concrete can bond TIGHTLY to them
When does post tensioning occur?
After the concrete has achieved its design strength
What type of buildings are tilt panels typically used on?
Buildings that are 2-3 stories tall
To cast tilt up panels on an existing slab you must use a ____ _______
bond breaker
In order to lift the tilt up panels, one type of insert used is a _____ _____ _____ _______
remote release system insert.
When choosing a crane, several important points must be considered, one of them is the _____ of the panel.
weight
What must be installed and secure immediately after the panel is set in place?
Braces
For precise elevation control, tilt up panels are set on steel ___
shims
Tilt up sandwich panels use what kind of insulation between the two layers (wythes) of concrete?
isocyanurate(Rigid Foam)
What is the average energy savings of a tilt up sandwich panels?
20-60%
What is a vital component of sandwich panels?
The connectors that tie the two layers together
Concrete stairs are classified as either ______ or ______
interior or exterior
Stairs require steel reinforcing, the mat is placed in the throat (sometimes called the effective depth) of the stair.
Placement is closer to the ______ because the load is from the top.
bottom
Building code
Exterior stairs must be supported by piers 150mm in diameter or concrete foundation wall _____ thick
200mm
The bottom edge of the riser board should be ______ to allow for troweling.
beveled
What are the 2 major components of bridges?
- An upper superstructure
- A lower substructure
Why are pre cast components used extensively in bridge construction?
Because of the longer spans and lighter weights of the units.
Concrete _____________ are used to support the superstructure girders.
bridge seats/ bearing plates
____ _____ can be used to support pier cap formwork
Friction collars
What is a diaphragm ?
A short wall used between sections or girders.
What supports the ends of the bridge structure?
Abutments and piles
The use of _____-_____ cables supports more tensile strength and allows greater spans.
post-tensioned
