Brannigan's Building Construction for the Fire Service Chapter 2
What is a precast in reference to building materials?
a concrete member that is cast and cured in a place other than its final position in the structure
What is a moment connection?
a connection between columns and beams that adds to resistance to lateral loads
What is a gravity connection?
a connection that relies on the weight of the building to hold it in place
What is monolithic concrete?
a construction technique in which all successive poured concrete castings are joined together so that the structure seems to be like one piece of stone
What is a serpentine wall?
a curving wall
What does it mean to say a building is pinned?
a description for structural elements that are connected by simple connectors such as bolts, rivets, or welded joints
What is a bracket?
a diagonal member that supports what would otherwise be a cantilever
What is a weep hole?
a drainage hole is a masonry wall that allows water trapped inside the wall to escape
What are diaphragm floors?
a floor designed to stiffen a building against wind and other lateral loads
What is torsion?
a force tending to twist a structure
What is a lateral impact load?
a force that acts on a structure from a horizontal direction such as wind or seismic forces
What is an eccentric load?
a force that is perpendicular to the plane of the section, but does not pass through the center of the section
What is tension?
a pulling or stretching force in line with the axis of the body, the opposite of compression
What are vierendeel trusses?
a rectangular truss with very strong corner bracing
What is a tie rod?
a rod used in tension to hold parts of a structure together
What is a spaceframe roof?
a roof that includes 3-d pyramid-like trusses
What is an example of a torsional force?
a screwdriver turning a screw
What is a grillage?
a series of closely spaced beams designed to carry a particularly heavy load
What is a pier?
a short column of masonry, usually rectangular, used to support horizontal cross sections
What is a suspended beam?
a simple beam with an additional beam added on both ends that is suspended on a tension member such as a chain cable or rod
What are wythes?
a single continuous vertical wall of masonry unit
What is an example of tensile forces?
a steel cable supporting a suspended walkway
What is a wall?
a structural element that transmits compressive forces, received along any point, to the ground
What is a beam?
a structural member that transmits forces perpendicularly to the reaction points
What is braced frame construction?
a structural system that uses diagonal members to provide bracing against lateral wind and earthquake loads
What is moment frame construction?
a structural system that utilizes special moment connections between columns and beams to resist rotation due to lateral loads
What is a parallel chord truss?
a truss in which both the upper and lower chords are parallel to each other
What is an inverted king post truss?
a truss incorporating a single compression member, it is inverted because the compression member extends downward
What is a triangle truss?
a truss that is triangular in shape, used to create a peaked roof
What is a 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 or steel dog similar to a big staple is used to provide minimal stability, often used in heavy timber construction
What is a precast concrete tilt slab wall?
a type of wall that acts as a verticle cantilever when it is being erected and is braced by tormentors or bracing poles
What is a watt?
a unit for measuring the energy release rate of a fire
What is a megastructure?
a very large structure
What is a demising wall?
a wall bounding a tenant space
What is a cavity or hollow wall?
a wall built of two types of wythes separated by a space for rain drainage or insulation
What is a composite wall?
a wall composed of 2 or more masonry materials that react together under load
What is a rubble masonry wall?
a wall composed of inner and outer wythes of masonry
What is a non load bearing wall?
a wall supporting no other load than its own weight
What is a structural frame?
all members of a structure that are tied together to carry the imposed loads to the substructure
What is the gravity resistance system?
all of the structural elements of a building and the connections that support and transfer the loads
What is a flitch plate girder?
made by sandwiching a piece of steel between two wooden beams
What is a buttress?
mass of masonry built against a wall to strengthen, used when a vault or arch places a heavy load or thrust on a part of a wall
What is a kilojoule?
metric unit approximate equivalent to BTU
How is stress measured?
pounds per square inch (psi) & pounds per square foot (psf)
What is fire resistance?
the ability of a material to avoid ignition, combustion, and the thermal effects of fire
What is the caloric value?
the amount of heat necessary to raise 1 pound of water 1 degree F
What is stiffness?
the capacity of a member or framework to resist imposed loads without excessive deflection
What does the variable Q express?
the heat release rate (hrr)
What is the heat release rate (hrr)?
the rate at which potential heat in a fuel is released
What is a safety factor?
the ratio of the strength of the material just before failure to the safe working stress
What is the fire problem with suspended load construction?
the tensile members have less fire resistance than large columns, the loads can not properly be delivered to the foundation and can cause collapses much quicker
What is a live load?
the weight of the building contents
What is a needle beam?
thin beams that are inserted to the foundation of an existing wall when a change is being made
What is the attitude of a beam?
vertical or horizontal orientation
What is a homogenous wall?
when describing wall construction, a wall that acts as one unit, good bonding exists between bricks, blocks and mortar
What does KIP mean?
1000 pounds force
What is a kilowatt?
1000 watts, a unit for measuring energy release rate in a fire
What is a megawatt?
1000000 watts, a unit for measuring the energy release rate of a fire
What happens as a column gets longer?
Its load-carrying capacity decreases
What is the formula for Euler's law?
Pc=3.1415^2 x EI/L^2 Pc is the critical load, the absolute maximum load E is the elasticity and the ability of the column to return to original shape I is the moment of inertia L^2 is the length of the column squared
What is a reaction?
The response in structures to the imposed loads, which are generally developed at the supports
What is a fixed beam?
a beam held together rigidly at two points, may cause wall collapse if the beam collapses and the connection do not yield properly
What is a cantilevered beam?
a beam supported at one end only, held rigidly in position at that end
What is a continuous beam?
a beam supported at three or more points, it is considered advantageous because if the span between two supports is overloaded the rest of the beam assists in carrying the load
What is a joist?
a beam supporting part of the structure of the building, typically arranged in parallel series to support a floor or ceiling
What is a truss?
a beam that is a framed structure arranged in a single plane in such manner that loads applied at the points of intersections of the members will cause only direct stress in the members
What is an overhanging beam?
a beam that projects beyond its supports, but not far enough to be considered a cantilever
What is a girder?
a beam that supports other beams
What is a transfer beam?
a beam that typically carries a load around a large opening or over an area on order to avoid intervening columns
What is a lightweight truss?
a collection of lightweight structural components that can be used to support either floors or roofs
What is a wall column?
a column of steel, reinforced concrete, or solid masonry within a block wall
What is an example of compression forces?
a concrete column supporting a floor
What is a spandrel girder?
a girder that ties wall columns together in a framed building
What is a suspended load?
a hanging load supported from above
What is a steel joist, or bar joist?
a lightweight steel truss joint
What is a bent?
a line of columns in any direction
What is a concentrated load?
a load acting on a very small area of the structure's surface, the opposite of a distributed load
What is a uniformly distributed load?
a load that is applied evenly over an area
What is a repeated load?
a load that is implied intermittently
What is an axial load?
a load that passes through the centroid of a section of construction and is perpendicular to the place of the section
What is a party wall?
a load-bearing wall that is common to two structures
What is a pilaster?
a masonry column projecting from one or both faces of the wall in which it is located
What is a stretcher?
a masonry unit laid horizontally with its length in the direction of the face of the wall
What is a header?
a masonry unit that overlaps 2 or more adjoining wythes of masonry to tie them together
What is a composite material?
a material that is made up of different parts and pieces
What is a live load?
a moving, variable weight added to the dead load or intrinsic weight of a structure
What is a panel wall?
a non-load bearing enclosing wall on framed buildings
What is a partition wall?
a non-load bearing wall that subdivides spaces within any story of a building or room
What is a rising roof?
a phenomenon in wood trusses in which difference in moisture levels between upper and lower wood truss chords cause the truss to bend and create a rise in the roof
What is a queen post truss?
a truss with two compression members
What is a veneer wall?
a wall made up of a single vertical thickness of masonry that is designed to improve the exterior appearance of a building
What is a shear wall?
a wall that counteracts the effects of lateral loads such as wind and earthquakes
What is a knee wall?
a wall typically found in the top floor of a wood-frame home with a peaked roof
What is sand-lime mortar?
a water-soluble mixture used in the past as mortar
What is a voussoir?
a wedge shape block whose converging sides radiate from a center, forming an element of an arch or vaulted ceiling
What is a ledger board?
a wood board typically attached to a walls studs that is used to support wood joists
What is K-bracing?
an arrangement of braces between columns tht represent the letter K
What is a camber?
an upward rise
What is self-weight?
another term for dead load, the overall weight of a building with all of its structural and construction materials
What is a dead load?
another term for self-weight,the overall weight of a building with all of its structural and construction materials
What is an added dead load?
any addition to a building's original dead load such as air conditioning units being added to a roof
What is an added live load?
any additional weight added to the current live load
What is a cross wall?
any wall at right angles to any other wall, the walls should brace one another
What is a load bearing wall?
any wall that carries a load in addition to its own weight
What is a built up girder?
beam made of steel plates and angles riveted together, as distinguished from one rolled from one piece of steel
How can you increase the load-carrying capacity of a column?
by using bracing
What is a wet joint?
cast-in place concrete that unites the rods projecting from precast sections
What is hurricane bracing?
comoponents of a hurricane resistance system that prevent uplift of a structure
What are structural elements?
components of a structure that are tied together to carry the imposed loads to the substructure and the ground
What are the four general types of forces that can be applies to a structural member?
compression, tension, torsion, and shear
What is reinforced concrete?
concrete that has steel imbedded within it in such a manner that the two materials act together in resisting forces
What is a gusset plate?
connecting plate made of a thin sheet of steel used to connect the components of the truss
What is a brick and block composite wall?
consists of an exterior wythe of brick directly mortared of parged to an inner wythe or concrete masonry unit
What is the difference between a dead load and a live load?
dead loads can be accurately calculated live loads are indeterminate and must be estimated based on the projected use of the building and such variables such as snow, wind, and rain
What is a plastic design?
design based on connections that redirect overloads to other sections of the building
What is a raker?
diagonal bracing columns
What is compression?
direct pushing force in line with the axis, the opposite of tension
What is tube construction?
externally braced structure
What is shear?
forces occurring within a building member when opposing forces pull the member in opposite directions
What are loads according to NFPA 5000?
forces or other actions that result from the weight of the building materials, occupants, occupants' possessions, environmental effects, differential movement, and restrained dimensional changes
What is the eternal enemy of every building?
gravity
What is portal bracing?
heavy riveting of girders to columns from the top to the bottom of the frame
What is core construction?
internally braced structure
How is strain measured?
it is measured in in fractions of an inch of deformation per inch of original length of the material
How does fire effect structural elements?
it weakens and destroys the structural elements and/or the connections between them, this can place loads on other elements that cannot handle them which could result in a collapse
How do you measure the fire load using the metric system?
kj/m^2
What is Euler's law?
law that states that there is a critical load for a column and the addition of even a single atom over the critical load can cause sudden buckling and collapse
What is a BTU?
short for British Thermal Unit, the amount of heat necessary to raise 1 pound of water 1 degree F at 1 atmospheric pressure and temperature of 60 degress
What are arches?
structural elements that combine the function of a beam and column
What is a rigid frame?
structural frame in which all columns beams are rigidly connected
What is a column?
structural member that transmits a compressive force along a straight path in the direction of a member
What are ties?
tensile connecting members of a truss web
What is a centroid?
the center point at which a body would be stable
What is deflection?
the deformation or displacement of a structural member as a result of loads acting on it
What is an impact load?
the effect of a moving load upon a stationary structure
What is a fire cut?
the end of a joist that is cut at an angle to permit the joist fall out of a wall without damaging the load bearing wall
What is a web?
the group of struts ties and panel points in a truss
What is a material's ultimate strength?
the highest load that a member or structure can sustain before failure occurs
What is a 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
What are stress and strain in reference to a building?
the internal force per unit area that produces a deformation and the actual percentage of deformation when a material is under stress
How is fire resistance closely related to mass?
the less mass an element is inherently less fire resistant
What is a neutral axis?
the line along witch the length of the beam does not change
What is a foundation?
the lower division of a building that serves to transmit and anchor the loads from the superstructure directly to the ground
What is transmission of loads?
the manner in which a load is spread from the point of application to the ground
What is torque?
the measurable turning force applied to a structural member
What is an example of a shearing force?
the movement of tectonic plates against each other
What is a chord?
the outside members of a truss as opposed to the inner webbed members
What is a wind load?
the positive or negative force of the wind acting on a structure
What is a fire load?
the potential fuel for a fire in a building
What is a fire wall?
wall with a fire-resistive rating and structural stability that separates buildings or subdivides a building to prevent the spread of fire
How do you measure the fire load in BTU/sq ft?
weight of the fuel x caloric value/ floor area
