Chapter 11- Fire Resistive Construction Flashcards
The problems that fire departments face regarding concrete construction can be divided into three distinct areas:
- Collapse during construction with no fire
- Fire during construction
- Fire in completed, occupied buildings
For any unit area, steel has __ times the compressive strength of concrete. Steel is, however, more costly.
15
Autoclaved Aerated Concrete Units (AAC) may be formed into panels, blocks, and floor slabs. It can be cut easily, thereby obtaining the desired dimensions. In terms of fire protection, the material has held up well when tested in an American Society for Testing and Materials (ASTM) E-119 furnace, achieving a __ hour rating with an __ inch thick block wall.
4
8
A major advantage of __ __ is that the floors can be thinner. Thinner floors will allow several more rentable floors in a tall building.
Post tensioning
There is an economic limit to the height of an ordinary brick bearing wall building. This exists because of the requirement that the walls increase in thickness as the building’s height increases. The limit is generally about __ stories, but there are brick bearing wall buildings as tall as __ stories.
6
16
In recent years, it has become possible to build brick bearing wall buildings __ or more stories in height, with no wall thicker than __ inches.
20
12
Concrete poured at __ degrees F will develop __ more pressure than at __ degrees F.
50
1/3
70
Sometimes workers burn scrap wood in steel barrels or use kerosene heaters to keep warm. By far the most dangerous, and perhaps most common heating method is the use of __.
Liquefied petroleum gas (LPG)
__ __ structures include bridges and parking garages. Post tensioned concrete presents a greater catastrophic collapse hazard during a fire than does conventional __ concrete.
Post tensioned
reinforced
Fireproofing of steel is classified as __ or __.
Individual
Membrane
__ fireproofing provides protection for each piece of steel.
Individual
__ fireproofing does not protect individual members. In one method, wire lath and cement plaster are used. In another method, the fireproofing of the floor is accomplished by a rated floor–ceiling assembly.
Membrane
The disadvantage of concrete is it __. In the effort to reduce dead weight of a building, and thus its cost, fireproofing is often a tempting target.
Weight
One of the fire protection advantages of concrete construction is that it lacks __ voids.
Inherent
The concrete in fire resistive construction serves two purposes;
- It resists compressive stresses.
- It protects the tensile strength of steel from fire.
