Ch 6 Alternative and Evolving Construction Trends Flashcards
This approach emphasizes how a building needs to be constructed and is less focused on the end performance. It is strict codes regulations and standards that drive this approach. It places the contractor in a position to make many workaround type decisions when things don’t exactly fit or material requirements are not specified or available.
Prescriptive building approach (contractor) - Industrial & Legacy
This approach to building is more concerned with what a building is required to do, and not necessarily with how it is to be constructed. It is an approach that concentrates on the ends, and not the means to the end. It also allows material suppliers to diversify and innovate and allows building designers to consider alternative materials and methods.
Performance design approach
(suppliers/designers)
For this steel building, C-channel and H-channel shape studs, sills, headers, and joists are used, 1/8 in thick with OSB sheeting to achieve strength
True lightweight steel frame building
For this lightweight steel style, lighter I-beams, and H-columns are used to form the external skeleton of the building (Sometimes referred to as red iron). Lightweight C-channels steel studs are used to fill the exterior and internal wall sections. Lightweight steel 1/8 inch is commonly used in truss configuration (open-web bar joists) for structural members in many types of roofs.
Post and beam steel
(skeleton)
Concerning lightweight steel buildings, the biggest collapse threat of these come with?
A fire in an unfinished basement
These buildings use permanent expanded polystyrene (EPS) forms for poured concrete and come as panels, planks, or blocks
Insulated concrete form (ICF)
Other forms of ICF
Percentage of cement to product: cellular concrete, cement-bonded polystyrene beads, cement-bonded wood fiber
OR
Combination of cement and mineralized wood chips
15% cement 85% recycled expanded polystyrene
15% cement and 85% mineralized wood chips
In the 1990s, builders started to use the ICF concept to form all exterior walls as high as ____ stories
3
ICF buildings over ____ stories are likely to be more like a reinforced concrete building with substantial use of steel
3
ICF decking is gaining popularity as it weighs about ____ percent less than conventional concrete flooring
40%
Three principal methods to build an ICF wall
- Flat panel
- Post and beam
- Grid block
This system creates just that - a concrete post and beam skeleton typically with steel rebar formed by using a combination of EPS planks and panels to form the hollow molds for the concrete post and beams. The finish post and beam ICF wall can range from ____ to _____percent concrete.
Post and beam
40-60%
“Some benefits”
This ICF system is one where thick EPS blocks are stacked in interlocked (like Lego blocks) to create a wall designed with internal cavities, where the concrete forms the lattice or waffle pattern. The concrete used to fill the cavities has to be high slump with minimal or small aggregate content with as _____ to _____ concrete
Grid block
20-30%
“Should cause firefighters concern”
This system uses interlocking pieces of EPS to form a mold, wherein a solid mass of concrete is poured. This is continuous mass of concrete, like a conventionally poured foundation wall. The concrete can be low slump with high aggregate content, preventing a fairly resistive mass for fire conditions. The finish wall is approximately ____ concrete and ____ EPS and steel
Flat panel
80% & 20%
“ Friend to firefighter”
This building is constructed with a panel that consists of two outer skins of OSB, with an insulating core made from expanded or extruded polystyrene (EPS or XPS, EPS most common). Panels range from 4 x 8‘ two as large as 8 x 28‘ or even 10 x 36‘.
Structural insulated panels (SIPs)
SIPs can be built _____ high without a substructure. Taller than ____ floors use a steel post and beam skeleton with sips infill.
Up to 3 stories
3
Conventional type ____ and type _____ buildings may be roofed with SIPs.
III and IV
Two variants of the SIP concept are the EPS core is replaced with a proprietary fill made from ____.
The second variant replaces ___ with ____ that help provide more impact resistance for buildings in hurricane prone areas.
Compressed wheat straw or cellulose
OSB - Thin steel plates
Modern straw bale construction could be of two forms?
Loadbearing (also called Nebraska style) (Straw Bale Building SBB)
Non-load bearing (wood or steel post and beam, bales for infill)
Toe up and bucks are two features of what construction type?
Load-bearing straw bale construction (Nebraska style) (straw bale building SBB)
The real collapse threat with the Straw Bale Building (SBB) is found with?
The roof (engineered wood truss, SIP or solid wood joist/truss)
Drying in straw clay buildings can take?
1-2 months
____ construction is not a construction type. It is instead an approach to construction.
Green
Concerning radiant barrier sheathing, when installed as ____ sheathing, the foil must be facing outward. When installed as _____ sheathing, the foil must be facing inward. A _____ in. airspace should be maintained in front of the foil.
Wall
Roof
3/4 in.
_____ live green roofs typically have a soiled depth of 2 inches to 4 inches
Extensive
(2 x 4 = x equals Extensive)
____ live green roofs typically a soil depth of over 1 foot
Intensive
_____ refers to a variety of wood framing techniques that reduce the amount of lumber and waste used to construct the wood frame building. This is also known as ____.
Advance framing methods (AFM)
Optimal value engineering (OVE)
The AFM framing technique is environmentally friendly, uses ___ to ___ less lumber, and reduces the framing factor from ____to ____.
10-30%
15-25%
Cellulose insulation is a green insulation that consists of _____ percent recycled newspaper
80%
This is the movement of heat through framing members
Thermal bridging (one purpose of AFM/OVE is to reduce this)
The ____ system uses a galvanized steel frame with carbon fiber reinforced EPS for panel fill
ThermaSteel
A wood beam that has layers of high-strength synthetic fiber material sandwiched and bonded to layers of cut timber or laminated strand lumber (LSL). Carbon graphite strands can also be sandwiched in place of the synthetic fiber material.
Fiber reinforced product (FiRP)
Can carry TWICE the load of similar dimension solid wood beam
A live green roof consists of 4 basic elements:
1) Roof capable of
supporting additional
weight
2) Multiple membrane
layers
3) Layer of soil
4) Planted vegetation
Mortarless blocks are like CMU’s but have unique engineered internal shapes filled with EPS. The blocks contain perhaps ____ the amount of concrete as a common CMU.
Half
Autoclaved Aerated Concrete (AAC) has ___the weight of a similar size concrete block
1/5
Block mostly air
This method can be defined as building construction materials, assemblies, and systems that are nontraditional, unusually innovative, or don’t readily fit into the five classic types
Alternative building methods
With alternative construction, what two variations of methods and materials are there?
- Incorporate a mix of standard and alternative methods and materials
- Methods or materials that could be best described as leading edge, innovative, or in some cases, substandard as compared to the conventional construction methods and materials of yesterday
The current advantages of using lightweight steel, as compared to wood, are numerous: (5)
- Reduced cost
- Significant weight reduction
- Ease of installation
- Resistant to termites and mold
- Noncombustible material to help
satisfy code requirements for certain
occupies
The interior finish of lightweight steel construction uses drywall. An ADDITIONAL hazard associated with lightweight steel, particularly C-channel steel studs is:
Heat can cause the studs to warp/twist pulling the attaching screws out of the drywall, allowing fire to extend any horizontal direction
With straw clay buildings, the spread of fire will primarily come from what?
Flammable materials within interior of the building
As it relates to firefighting, green buildings may bring challenges such as: (4)
- Alternative power sources
- Unusual or increased dead and live -
loads - Low mass synthetics
- Recycled or repurposed materials
This is not a new framing technique, but is beginning to be used to provide an energy efficient envelope for exterior walls. Studs are either aligned or staggered, and only one set of studs is loadbearing.
Double stud wall construction
Which Green consideration is capable of enhancing flashover conditions as well as will greatly diminishing the effectiveness of thermal imaging cameras used to find hotspots?
Radiant barrier sheathing (RBS)
This can also be referred to as manufactured board, man-made, wood, and composite wood, which includes a diverse range of EWP’s, that are primarily manufactured by binding fibers, strands, particles, or veneers of wood together with adhesives.
Engineered Wood
Two ways to compress bales (SBB)
- Adding weight to roof
- Compression straps
This modular panel system is EPS sandwiched between steel wire mesh and sprayed with shotcrete at the building site.
Insteel 3-D Panel System
2x 4 framing, OSB sheathing covered with a peel-and-stick membrane (rubberized asphalt adhesive backed by a layer of high-density cross-laminated polyethylene) and single or multiple layers of rigid extruded polystyrene foam insulation.
pressure-equalized rain screen insulated structure technique (PERSIST)
