Chapter 2 Flashcards
Concepts of Construction
Arch
Combines the function of a beam and a column
Attitude
Vertical or horizontal orientation
Axial Load
A load that passes through the centroid of a section under construction and is perpendicular to the plane of the section.
Bar Joist
Lightweight steel truss joist
Beam
A structural member that transmits forces perpendicular to such forces to the reaction points
Bent
A line of columns in any direction
Braced Frame
A structural system that uses diagonal members to provide bracing against lateral wind and earthquake loads
Bracket
Diagonal member that supports what would otherwise be a cantilever
Brick and Block Composite Wall
Consists of of an exterior wythe of brick directly mortared or parged to an inner wythe of concrete masonry unit (CMU).
BTU
British thermal unit. the qty of heat required to raise 1lb of water 1deg F at the pressure of 1 ATM and temp at 60F.
Built-up Girder
Made of steel plates and angles riveted together, as distinguished from on rolled from one piece of steel
Buttress
Mass of masonry built against a wall to strengthen it. Necessary when a vault or an arch places a heavy load or thrust on one part of a wall
Caloric Value
Measured in BTU, the amount of heat required to raise 1lb of water, 1 deg F
Camber
Upward rise
Cantilever Beam
A beam supported at one end only, rigidly held in position at the end.
Cantilevered
Supported by a cantilever
Cavity or Hollow Wall
A wall built of 2 wythes, separated by a space for rain drainage or insulation
Centroid
The center point at which a body would be stable, or balance, under the influence of gravity
Chord
The outside members (top or bottom) of a truss, as opposed to the inner “webbed” members
Column
A structural member that transmits a compressive force along a straight path in the direction of the member
Composite
Built up of different parts, pieces, or materials
Composite Wall
A wall composed of 2 or more masonry materials that react together under a load
Compression
Direct pushing force, in line with the axis member; the opposite of tension
Concentrated Load
A load acting on a very small area of the structure’s surface; the exact opposite of a distributed load
Continuous Beam
A beam supported at 3 or more points. it is considered structurally advantageous because if the span between 2 supports is overloaded, the rest of the beam assists in carrying the load
Core Construction
No external braces involved
Cross Wall
Any wall at right angles to any other wall; the walls should brace one another
Dead Load
The weight of a building; the dead load consists of the weight of all materials of construction incorporated into a building; including all structural and built in features, and the weight of cranes
Deflection
the deformation or displacement of a structural member as a result of loads acting on it
Demising Wall
Wall bounding a tenant space
Diaphragm Floor
A floor designed to stiffen a building against wind a lateral loads such as earthquakes
Eccentric Load
A force that is perpendicular to the plane of the section but does not pass through the center of the section
Fire Cut
The end of a joist that is cut at an angle to permit the joist to fall out of a wall without damaging the load-bearing wall
Fire Load
The potential fuel available for a fire in a bldg
Fire Resistance
The ability of a material to avoid ignition, combustion, and the thermal effects of a fire
Fire Wall
Wall with a fire-resistive rating and structural stability that separates blgs or subdivides a bldg to prevent the spread of fire
Fixed Beam
Beam supported at 2 points and rigidly held in position at both points. This rigidity may cause collapse of a wall if the beam collapses and the rigid connection does not yield properly
Flitch Plate Girder
Made by sandwiching a piece of steel between 2 wooden beams
Foundation
The lower division of a bldg that serves to transmit and anchor the loads from the superstructure directly to its earth or rock, usually below ground level
Gang Nail
Another name for a gusset plate in a lighweight wood truss
Girder
A beam that supports other beams
Gravity Connection
A connection that depends on the weight of the bldg to hold it in place
Gravity Resistance System
All of the structural elements of a bldg and the connections that support and transfer the loads
Grillage
A series of closely spaced beams designed to carry a particularly heavy load
Gusset Plate
(lightweight wood truss) Connecting plate made of a thin sheet of steel used to connect the components of the truss
Header
A masonry unit that overlaps 2 or more adjoining wythes of masonry to tie the together
Heat Release Rate (HRR)
The rate at which the potential heat in a fuel is released
Homogenous
When describing wall construction, a wall that acts as 1 unit (good bonding exists between bricks, blocks, and mortar)
Hurricane Bracing
Components of a hurricane resistance system that prevent uplift of the components of a structure, including galvanized steel straps used to connect roof trusses to stud walls and anchor bolts used to connect stud walls with sill and sole plates
Impact Load
The effect of a moving load upon a stationary structure
Inverted King Post Truss
A truss incorporating a single compression member; it is inverted because the compression member extends downward
Joist
A beam
K-Bracing
An arrangement of braces between columns that resembles the letter “K”
KIP
1000 lbs of force
Kilojoule (kJ)
Metric unit approximately equivalent to 1 BTU
Kilowatt (KW)
A unit for measuring the energy release of a fire
Knee Wall
A wall typically found in the top floor of a wood-frame home with a peaked roof. This short wall square off the triangular area at the edge of the room where the sloping roof meets the floor
Lateral Impact Wall
A force that acts on a structure from a horizontal direction, such as wind or seismic forces
Ledger Board
A wood board typically attached to a wall’s studs that is used to support wood joists
Lightweight Truss
A collection of lightweight structural components joined in a triangular unit that can be used to support either floors or roofs
Lintel
The horizontal beam that forms the upper structural member of an opening for a window or door and supports part of the structure above it
Live Load
The weight of the bldg contents
Load
Force or other action that results from the weight of all bldg materials, occupants and their possessions, environmental effects, differential movement, and restrained dimensional shapes
Load-bearing Wall
Any wall that carries a load in addition to its own weight
Megastructure
A very large structure
Megawatt (MW)
A unit for measuring the energy release rate of a fire
Moment
The tendency of a force to rotate or twist a structural member
Moment Frame
A structural system that utilizes special “moment” connections between columns and beams to resist rotation due to lateral loads such as earthquakes and wind
Monolithic Concrete
A construction technique in which all successive poured concrete castings are joined together so that the structure seems to be like 1 piece of stone
Needle Beam
When any change is to be made in the foundation of an existing wall, the wall must be supported. Often holes are cut through the wall, and so-called needle beams are inserted and supported on both sides, They pick up the load of the walls
Neutral Axis
The line along which the length of the beam does not change
Non-load-bearing wall
A wall supporting no load other than its own weight
Overhanging Beam
A beam that projects beyond its support, but not far enough to be a cantilever
Panel Points
The connection points joining ties, struts, and chords in a truss
Panel Wall (curtain wall)
Non load bearing enclosing wall on framed bldgs
Parallel-chord truss
A truss in which both the upper and lower chords are parallel to each other
Partition wall
A non load bearing wall that subdivides spaces within any sort of bldg or room
Party Wall
A load bearing wall that is common to 2 structures
Pier
A short column of masonry, usually rectangularin horizontal cross section, used to support other structural members
Pilaster
A masonry column projecting from 1 or both faces of the wall in which its located
Pinned
A description for structural elements that are connected by simple connectors such as bolts, rivets, or welded joints
Plastic Design
Design based on connections that redirect overloads to other sections of the bldg
Portal Bracing
Heavy riveting of girders to columns from the top to the bottom of the frame
Precast
A concrete member that is cast and cured in a place other than its final position in the structure
Precast Concrete Tilt Slab Wall
A type of wall that acts as a vertical cantilever when it is being erected and is braced by tormentors or temporary bracing poles
Q
A designation of the HRR; refers to the rate at which a fuel will burn
Queen Post Truss
A truss with 2 compression members
Rakers
Diagonal bracing columns
Reaction
The response in structures to the imposed loads , which are gradually developed at the supports
Reinforced concrete
In concrete masonry construction, steel reinforcement that is embedded in such a manner that the 2 materials act together in resisting forces
Repeated Load
A load that is applied intermittently
Rigid Frame
Structural frame in which all columns and beams are rigidly connected. There are no hinged joints, and the angular relationship between beam and column members is maintained under load
Rising Roof
A phenomenon in wood trusses in which differences in moisture levels between the upper and lower wood truss chords cause the truss to bend and create a rise in the roof
Rubble Masonry Wall
A wall composed of inner and outer wythes of coursed masonry. The space between the wythes is filled with random masonry , sometimes mixed with mortar. Such walls are unstable to lateral thrust
Safety Factor
The ratio of the strength of the material just before failure to the safe working stress
Sand-lime mortar
A water-soluble mixture used in the past as mortar, when water is applied, the mortar can be washed away
Self-releasing Floor
A type of floor in which floor girders are set on anchor boxes in walls and caps attached to columns. A wood cleat or steel dog-iron similar to a big staple is used to provide minimal stability. Often used in heavy-timber construction.
Self-weight
Another term for dead load
Serpentine Wall
A curving wall
Shear
Forces occurring within a building member when opposing forces pull the member in opposite directions
Shear Wall
A wall that counteracts the effects of lateral loads such as wind and earthquakes
Simple Beam
A beam supported at 2 points near its ends. In simple beam construction, the load is delivered to the 2 reaction points and the rest of the structure renders no assistance in an overload
Spaceframe
A 3D pyramid-like truss
Spandrel Girder
A girder that ties wall columns together in a framed blgd
Steel Joist
An open web design used for the support of floors and roofs
Stiffness
The capacity of a member of framework to resist imposed loads without excessive deflection
Strain
The actual percentage of elongation (deformation) when a material is stressed
Stress
Force per unit area that produces a deformation
Stretcher
A masonry unit laid horizontally with its length in the direction of the face of the wall
Structural Elements
Components of a structure that include beams, trusses, columns, arches, and walls
Structural Frame
All members of a structure that are tied together to carry the imposed loads to the substructure, and hence to the ground
Strut
A bracing column
Suspended Beam
A simple beam, with 1 or both ends suspended on a tension member such as a chain, cable or rod
Suspended Load
A hanging load supported from above
Tension
A pulling or stretching force in line with the axis of the body; the opposite of compression, which is pushing, crushing stress
Tie
(truss member) the tensile connecting members of a truss web
Tie Rod
A rod in tension, used to hold parts of a structure together
Torque
The measurable turning force applied to a structural member
Torsion
A force tending to twist a structural member
Transfer Beam
A beam that typically carries a load around a large opening or over an area in order to avoid intervening columns
Transmission
The manner in which a load is spread from the point of application to the ground
Triangular Truss
A roof truss that is triangular in shape, it is used to create a peaked roof
Truss
A type of beam that is a framed structure consisting of a triangle or group of triangles arranged in a single plane in such a manner that loads applied at the points of intersections of the members will cause only direct stresses (tension or compression) in the members
Tube Construction
Externally braced structure
Ultimate Strength
The highest load that a member or structure can sustain before failure occurs
Uniformly Distributed Load
A load that applied evenly over an area
Veneer Wall
A wall made up of a single vertical thickness of masonry that is designed to improve the exterior appearance of a bldg
Vierendeel Truss
A rectangular truss with very rigid corner bracing
Voussoir
A wedge-shaped block whose converging sides radiate from a center, forming an element of an arch or vaulted ceiling
Wall
A structural element that transmits to the ground the compressive forces applied along the top or received at any point on the wall
Wall Column
A column of steel, reinforced concrete, or solid masonry (such as brick or solid block) in a block wall. Concentrated loads such as main girders are applied to the wall directly above the wall column.
Watt (W)
A unit for measuring the energy release of a fire
Web
The group of struts, ties, and panel points in a truss
Weep Hole
A drainage hole in a masonry wall that allows water trapped inside the wall to escape
Wet Joint
Cast-in-place concrete that unites the rods projecting from precast sections
Wind Load
The positive or negative force of the wind acting on a structure
Wythe
A single continuous vertical wall of masonry units (1 masonry unit in thickness)
