Term
|
Definition
large members span between columns and smaller beams are framed into them
girders span the shorter distance, beams the longer
typical spans are 25-40', with beams spaces about 8-10' on centr
steel framing is usually covered with steel decking, and concrete is poured over the decking to form the slab
common to mid & high rise buildings
*limited space between the bottom of the girders and the suspended ceiling |
|
|
Term
| open-web steel joist system |
|
Definition
joists span between beams or bearing walls
can span from 20' to 144'
depths range from 8 to 72"
spaced 2-6' on center
usually in one story or low rise buildings with wide column spacing |
|
|
Term
|
Definition
concrete is poured into forms and allowed to harden
utilize only mild steel reinforcing set in the formwork before the concrete hardens
sometimes it is post-tensioned with steel cables to create extra compression force.
*if a slab is post tensioned, it cannot be penetrated for pipes or conduit |
|
|
Term
| 5 types of cast in place systems |
|
Definition
1. beam and girder system - spans of 15-30 feet
slab is poured integrally with beams
2. concrete joist system - concrete members are spaced 24 or 36" apart and frame into larger beams, slab is integral
*joists are close together, difficult to drill for pipes/conduit
3. flat plate construction - floor slab is designed and reinforced to transfer loads to the columns, which do not exceed 25' spacing
*typically used where floor to floor height must be kept to a minimum, difficult to drill because of close reinforcement
4. flat slab construction: drop panels are used around the columns (increased slab thickness) to increase strength
5. waffle slab system - two way joist system, provides for heavier loads at slightly longer spans than the flat slab system |
|
|
Term
|
Definition
factory made pieces
high strenght steel cables are stretched in the precasting forms before the concrete is poured. after the concrete attains a certain minimum strength, the cables are released, transferring compressive stresses to the concrete. |
|
|
Term
|
Definition
single & double tee popular because they serve as beam and floor decking, easy and fast to erect
a 2" concrete topping is put over the tees to make a smooth floor surface |
|
|
Term
|
Definition
support loads from above
include live loads (people/furniture) and dead loads (the structure itself) |
|
|
Term
| loadbearing walls in residential construction |
|
Definition
exterior walls, first story exterior walls of a two story
moderately sized openings can be cut with the use of additional studs and a double header |
|
|
Term
| loadbearing walls in commercial construction |
|
Definition
core walls of high building and cannot be pierced except for small openings for pipes
smaller commercial buildings, concrete and masonry walls are typically loadbearing |
|
|
Term
|
Definition
forces acting on building elements
include gravity, lateral, and dynamic |
|
|
Term
|
Definition
includes live and dead loads
initial design allows for allowance per sq. ft. of partitions on dead loads, consult if adding masonry or heavy equipment
high rise buildings, the structural bays at the center of the building are typically designed for heavier loading, so file rooms should be located in those areas during initial planning |
|
|
Term
|
Definition
wind and earthquake loads
in areas where earthquakes are an issue, partitions that are over 6' tall, or are attached to the ceiling, ceilings, ductwork, light fixtures, sprinkler & other piping, bookcases, storage cabinets,lab equipment, access floors need to be detailed to resist earthquake forces |
|
|
Term
|
Definition
sudden or radidly changing load
examples: automobiles in a parking garage, elevators, helicopter landing on the building |
|
|
Term
|
Definition
| installed at partitions that attach to structural floors above and to the perimeter of the building to allow the building to move slightly without putting pressure on the partitions |
|
|
Term
|
Definition
2-4" diameter
beam & girder and one-way pan joist systems the easist to penetrate because there is less reinforcing in these systems
flat plate and flat slab floors are the easiest to cut
Tee sections cannot be cut because they contain tension rods
post tensioned concrete cannot be cut |
|
|
Term
|
Definition
|
|
