CM 310 Midterm 2 || All Correct.
What is a flying form? correct answers a large pre-assembled formwork and falsework unit,
often forming a complete bay of suspended floor slab.
Difference between forming a suspended slab using hand set shores/forms and forms compared
to using a flying form system? correct answers Hand set shores take a lot of time and labor cost,
but if your building has repeatable floor design, a reusable flying form system can be much faster
and efficient hoisted by crane
Distinguish pretensioning vs post-tensioning systems ? correct answers Pretensioning= reduced
cracking and smaller structural members(less dead load) Cons= more skilled labor/higher quality
control----------------------------Postensioning= contains mild steel bars
What type of members precast or cast in place are typically associated with pre/post tensioning?
correct answers Pre tensioning is pre cast Post tensioning is on site
When is concrete placed in pre tensioning? correct answers At the precaster's plant
When is concrete placed in post tensioning? correct answers site cast members done at the
construction site
Distinguish gang wall form and a hand set wall form correct answers Gang wall is for floor slabs,
and large pre fabricated panel forms, Hand set wall forms are for non identical flooring systems
that have specific differences for each floor (nonrepeatable)
Know how long forms for suspended slab and beam soffits must remain in place correct answers
When the formwork from horizontal surfaces are stripped and moved to next level, they are still
supported by shores (reshoring), 70% of specified concrete strength are when horizontal
formwork can be moved
What are the essential components of a post tensioned system? correct answers Tendon- one or
more pieces of prestressing steel coated with protective coating and inside a duct or sheathing,
they have anchors to transmit forces into structure
How does an isolated slab on grade function? correct answers Has to be on undisturbed, stable
soils with no organic material. As long as bearing capacity of soil isnt too low, the slab can
distribute the load well around
Who is responsible for formwork design? correct answers General contractor, stripping time is
structural engineer
Identify essential methods used in forming a waffle slab and one way floor joist correct answers
Both use a dome that rests next to other domes creating squares throughout, When the concrete is
poured it only goes between the square domes creating a "waffle" appearance. One way floor
joists are long rectangular domes
, What type of reinforcing is used in a post tensioned elevated concrete floor? correct answers
Combo of common rebar and several high strength tendon reinforcing, stressed after concrete is
poured
What is total precast construction correct answers All concrete panels, members, beams casted
before site and connected on site, but nothing is newly poured
What is a precast hollow core slab correct answers A slab with voids in the central region,
reduces dead load by 40-50%
What is a pre cast double tee units correct answers Slab is connected to the beams in one pour
with two beams connected to create a double tee, typically 8ft wide and 4ft between beams, need
to be pre casted
What is a precasted inverted tee beam correct answers Typically used to support members for
hollow core slabs or double tee units, are prestressed
What is the purpose of a concrete topping on a hollow core slab correct answers If there is no
cover on top of hollow core, loads can be on top of voids and risk failure, with the added slab on
top, the loads can distribute better.
What is Precast method correct answers an industrialized reinforced concrete (RC) method
involving the use of factory produced PCa parts instead of full or in part production of cast-in-
site concrete. Environmentally friendly due to superior resource conservation.
What is site cast method correct answers Site cast method invovles all of the formwork and
planning to pour on site compared to pouring before and constructing
What is the difference between architectural pre cast concrete and structural precast concrete
correct answers Architectural is for an aesthetic and structural is for supporting the structure and
needs to hit a minimum psi strength
SIP Components (Structural Insulated Panel) correct answers - Expanded Polystyrene
- Facings may be oriented strandboard (OSB) or plywood
- The most common thickness of OSB facing is 1⁄2 in.
- SIP wall panels are either 4 ft or 8 ft wide
-
Types of panels manufactured and delivered to the job site correct answers - Based on the
analysis of the drawings, the manufacturer determines the size, shape, configuration, and
thickness of the panels and prepares necessary shop drawings for their fabrication.
- Because almost no cutting is required on site, the panels are shipped to the site when needed,
eliminating the need for elaborate site storage facilities.
What is a flying form? correct answers a large pre-assembled formwork and falsework unit,
often forming a complete bay of suspended floor slab.
Difference between forming a suspended slab using hand set shores/forms and forms compared
to using a flying form system? correct answers Hand set shores take a lot of time and labor cost,
but if your building has repeatable floor design, a reusable flying form system can be much faster
and efficient hoisted by crane
Distinguish pretensioning vs post-tensioning systems ? correct answers Pretensioning= reduced
cracking and smaller structural members(less dead load) Cons= more skilled labor/higher quality
control----------------------------Postensioning= contains mild steel bars
What type of members precast or cast in place are typically associated with pre/post tensioning?
correct answers Pre tensioning is pre cast Post tensioning is on site
When is concrete placed in pre tensioning? correct answers At the precaster's plant
When is concrete placed in post tensioning? correct answers site cast members done at the
construction site
Distinguish gang wall form and a hand set wall form correct answers Gang wall is for floor slabs,
and large pre fabricated panel forms, Hand set wall forms are for non identical flooring systems
that have specific differences for each floor (nonrepeatable)
Know how long forms for suspended slab and beam soffits must remain in place correct answers
When the formwork from horizontal surfaces are stripped and moved to next level, they are still
supported by shores (reshoring), 70% of specified concrete strength are when horizontal
formwork can be moved
What are the essential components of a post tensioned system? correct answers Tendon- one or
more pieces of prestressing steel coated with protective coating and inside a duct or sheathing,
they have anchors to transmit forces into structure
How does an isolated slab on grade function? correct answers Has to be on undisturbed, stable
soils with no organic material. As long as bearing capacity of soil isnt too low, the slab can
distribute the load well around
Who is responsible for formwork design? correct answers General contractor, stripping time is
structural engineer
Identify essential methods used in forming a waffle slab and one way floor joist correct answers
Both use a dome that rests next to other domes creating squares throughout, When the concrete is
poured it only goes between the square domes creating a "waffle" appearance. One way floor
joists are long rectangular domes
, What type of reinforcing is used in a post tensioned elevated concrete floor? correct answers
Combo of common rebar and several high strength tendon reinforcing, stressed after concrete is
poured
What is total precast construction correct answers All concrete panels, members, beams casted
before site and connected on site, but nothing is newly poured
What is a precast hollow core slab correct answers A slab with voids in the central region,
reduces dead load by 40-50%
What is a pre cast double tee units correct answers Slab is connected to the beams in one pour
with two beams connected to create a double tee, typically 8ft wide and 4ft between beams, need
to be pre casted
What is a precasted inverted tee beam correct answers Typically used to support members for
hollow core slabs or double tee units, are prestressed
What is the purpose of a concrete topping on a hollow core slab correct answers If there is no
cover on top of hollow core, loads can be on top of voids and risk failure, with the added slab on
top, the loads can distribute better.
What is Precast method correct answers an industrialized reinforced concrete (RC) method
involving the use of factory produced PCa parts instead of full or in part production of cast-in-
site concrete. Environmentally friendly due to superior resource conservation.
What is site cast method correct answers Site cast method invovles all of the formwork and
planning to pour on site compared to pouring before and constructing
What is the difference between architectural pre cast concrete and structural precast concrete
correct answers Architectural is for an aesthetic and structural is for supporting the structure and
needs to hit a minimum psi strength
SIP Components (Structural Insulated Panel) correct answers - Expanded Polystyrene
- Facings may be oriented strandboard (OSB) or plywood
- The most common thickness of OSB facing is 1⁄2 in.
- SIP wall panels are either 4 ft or 8 ft wide
-
Types of panels manufactured and delivered to the job site correct answers - Based on the
analysis of the drawings, the manufacturer determines the size, shape, configuration, and
thickness of the panels and prepares necessary shop drawings for their fabrication.
- Because almost no cutting is required on site, the panels are shipped to the site when needed,
eliminating the need for elaborate site storage facilities.
