7. BEAMS, JOINTS, GIRDERS, AND FLOORS

beam

rigid structural member designed to carry and transfer transverse loads across space to supporting elements (columns, posts, etc.)

joists

small, parallel beams for supporting floors, ceiling or flat roofs

girder

large, principal beam designed to support concentrated loads at isolated points along its length

floor

the level, base surface of a room or hall upon which one stands or walks

simple beams

have single span, with a support at each end (no restraint at the supports)

cantilever beams

supported by one end only

continuous beams

beams resting on more than two supports

solid

built-up

glue-laminated

flitch plate

box beam

spaced

reinforced concrete beam and girders

concrete beam designed to act together with longitudinal and web reinforcement in resisting applied forces

point of inflection

section of a beam at which the bending moment changes from positive to negative is called the  ____

rectangular beams

t-beams

type of RC beam where a reinforced concrete floor slab and its supporting beam are built at the same time and thoroughly tied together

beam with compression reinforcement

also called doubly reinforced beams, beams with reinforcement in the compression and tension side of the beam

cantilever beams

beams that are supported at one end only

hollow box girders

• double reinforced beams used for long spans

• hollowed in the center of the section to reduce its dead loa

bean brackets or corbels

short beam extensions from columns used to support rafters or trusses

I-beam

ideal type of steel beam

plate girders

a beam composed of a wide plate, known as a web, at the top and bottom of which are riveted angles and plates

box girders

a built up beam in which more than one web plate is used

open web steel joists

lightweight, shop fabricated steel members having a trussed web

light gauge steel joists

manufactured from cold formed sheet or strip steel

form an economical floor system that is lightweight, non-combustible, and damp roof

wood joist system

small joists members closely spaced

wood plank and beam

larger beams spaced further apart and spanned with structural planking or decking

concrete

precast or cast-in-place)

steel joist system

lightgage or open-web joists clearly spaced

joists supported by beams or walls

steel beam and decking

heavier beams spaced further apart and spanned with steel decking or precast concrete planks

• floor extension perpendicular to joists

• floor extension parallel to joists

wood floor framing extensions

wood beam w/ ledger

wood beam w/ lapped or spliced joists

steel beam w/ ledger

steel beam under joists

floor joists on beams/girders

sill

horizontal timber, at the bottom of the frame of a wood structure, which rests on the foundation

bridging

a brace, or a system of braces, placed between joists to stiffen them

One way solid slab and beam

most commonly used type of reinforced concrete construction

one way joist slab or ribbed slab

a one-way joist slab consists of relatively small adjacent T-beams

two-way waffle slab

a waffle slab is a two way concrete slab reinforced by ribs in two directions

two way flat plate

is a concrete slab of uniform thickness reinforced in two or more directions and supported by columns without beams or girders

two way flat slab

flat plate thickened at its column supports to increase its strength and moment-resisting capacity

drop panel or drop

area of increased thickness

slab on grade

concrete slab placed over a dense or compacted base and supported directly by the ground

form decking

serves as a permanent framework for a reinforced concrete slab until the slab can support itself and its live load

composite decking

type of metal decking; welding shear studs through the decking to the supporting beam below

cellular decking

welding a corrugated sheet to a flat steel sheet, forming spaces for electrical and communications wiring

solid flat slab

hollow core slabs 

single tees

double tees

rectangular beams

AASHTO girders

pre-cast concrete floor systems

• economical of materials

• eliminates cracks

• remarkable elastic properties

advantage of prestressed concrete