A

Abutment- a substructure element supporting each end of a single span or the extreme ends of a multi-span superstructure and, in general, retaining or supporting the approach embankment

Anchor Span- the span that counterbalances and holds in equilibrium the cantilevered portion of an adjacent span during construction

Anchorage- massive concrete structure, also called “cable anchorages” or “shore anchors;” these are placed far enough back from the edge of the water to insure against sliding. They provide stability where the cable end is tied, withstanding the tremendous stress of the loaded cables

Approach Slabs- the concrete transition from the asphalt roadway to a bridge

Asphalt- mixture of tar and rocks used to form roadway; asphalt is placed in several layers or lifts. Also called pavement, referencing how it is placed on the roadway

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B

Barrier Wall- concrete sections used to separate traffic from construction area

Beam- a rigid, usually horizontal, structural element

Bent- a substructure unit supporting each end of a bridge span; also called a pier

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C

Cable- a structural element formed from steel wire bound in strands; the suspending element in a bridge

Cable Saddle- the cable saddles sit at the top of each tower; they hold the main suspension cable where it crosses over each tower leg. As traffic, wind and temperature changes affect the movement of the cables; the saddles absorb the load and shift it to the towers

Cable Spinning- the technique of pulling wires from the anchorage over towers and back to form the main cable; a “spinning wheel” or “traveler” carries the wires that are grouped into strands then bound tightly together to form strong suspension cables

Cable-Stayed Bridge- a bridge in which the roadway desk is suspended from cables anchored to one or more towers

Caisson- a watertight, dry chamber in which people can work underwater

Cantilever- a projecting structure supported only at one end, like a shelf bracket or a diving board

Cast-in-Place- the technique of pouring concrete into a box form on a construction site to create a structural element in its final position

Catwalks- temporary foot bridges used by bridge workers during construction

Cement- One of the ingredients of concrete. Portland cement, the most common type of cement, is calcium silicate cement made with a combination of calcium, silicon, aluminum and iron.  A good way to emphasize the difference between cement and concrete is:  cement is to concrete as flour is to bread

Clearing and Grubbing- removal of trees, stumps, roots, etc.

Cofferdam- a temporary steel or concrete box erected in the water and then pumped dry to provide a work area

Concrete- materiel used to build roadways and sidewalks.  Concrete is a mixture of cement, aggregates (sand, gravel, stone) and water.  When water and cement are combined, a chemical reaction causes the cement to set and harden. When this mixture is added with the aggregates, it acts as an adhesive and holds the aggregates together to form concrete

Crack Relief Layer- Layer of liquid asphalt, rubber and stone used as an absorbing barrier to prevent cracking of the new asphalt layer.  This layer is placed on top of the milled surface before the first layer of structural course is paved.  It is also, referred to as ARMI, or Asphalt Rubber Membrane Interlayer

Culvert- drainage pipe

Curb & Gutter- a concrete surface with a raised lip at the edge of the pavement, which directs water away from the roadway and into a drainage structure- primarily used in urban areas without grassed medians

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D

Deck- the roadway portion of a bridge that directly supports vehicular and pedestrian traffic

Dowel- A pin of wood or metal used to hold or strengthen two pieces where they join

Downstream Face- the side of the dam that is not against the water

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E

Embankment- fill material, usually soil-type material, hauled to a project to build up a low area.  Large amounts of embankment are needed for building up a road surface to meet the bridge height

Eye-Bar- steel bars that hold wire strands of the main cable and that are attached to beams embedded in the concrete of an anchorage

Expansion Joint- a joint designed to provide means for expansion and contraction movements produced by temperature changes, load and other forces

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F

Fender- a wooden piling, usually upright and free-standing, driven into the ground beneath water to absorb some of the impact of docking vessels

Footing- The enlarged, lower portion of a substructure that distributes the structure load either to the earth or to supporting piles; the most common footing is the concrete slab; “footer” is a colloquial term for footing

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G

Girder- the enlarged, lower portion of a substructure that distributes the structure load either to the earth or to supporting piles

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L

Landscaping- beautification process where trees, shrubs and/or flowers are placed alongside roadways and in medians.  Sometimes it is included in road construction projects, but may also be done by local businesses or civic groups

Liquidated Savings- a monetary incentive to encourage contractors to finish projects ahead of schedule; it can be applied to specific phases of construction projects.  Often, it is used for projects in high traffic areas or phases having significant traffic impacts

Live Load- vehicular traffic

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M

Main Beam- a beam supporting the spans and bearing directly onto a column or wall

Maintenance of Traffic (MOT) - Maintenance of Traffic—any process used to control and maintain the movement of traffic in a construction zone.  It can include lane closures, lane shifts, detours, etc.

Median- a traffic separator between opposing traffic; it can be grass or concrete.  Grass medians are often landscaped for beautification

Milling-a process of removing old asphalt by grinding it off the roadway with a large machine; roads are generally milled prior to resurfacing

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O

Open Gate Bridge- a temporary, metal structure used during bridge replacement projects.  The bridge is prefabricated and re-assembled in sections on the project; it allows for faster completion of bridges because the old structure can be torn down and rebuilt in one process, while maintaining traffic

P

Paving- process of placing asphalt on a roadway; dump trucks pour hot asphalt into a paving machine, which then places a smooth layer of the asphalt on the roadway.  The hot asphalt is compacted with large rollers.  As asphalt cools, it hardens to form a strong roadway

Pier- a vertical supporting structure, such as a pillar

Pile- a long, round pole of wood, concrete or steel used as bridge supports driven into the soil by pile drivers

Pile Driver- a machine that repeatedly drops a heavy weight on top of a pile until the pile reaches solid soil or rock or cannot be pushed down any farther

Portal- the clear, unobstructed space of a bridge forming the entrance to the structure

Post-Tensioned Concrete- the embedded steel bards or cables that are stretched into tension after the concrete hardens

Pre-Tensioned Concrete- the embedded steel bars or cables that are stretched into tension before the concrete hardens

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R

Rebar- reinforcing bar (called rebar for short) used for concrete carrying a heavy load, such as footings, foundation walls, columns and pilasters

Reflective Pavement Markers (RPM)- reflectors used with painted markings to delineate travel lanes

Reinforced Concrete- concrete with steel bars or mesh embedded in it for increased strength in tension

Right-of-Way (ROW)- property owned and maintained by the Department of Transportation & Development on either side of a roadway.  On many projects, additional ROW property must be obtained before construction can begin.  It can include ditches, drainage ponds and sidewalks

Roller- machine used to compact road layers, such as asphalt or embankment.  Some rollers vibrate to help compact certain mixes of asphalt

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S

Seeding & Mulching- process of placing grass seed and ground cover, usually loose hay, to prevent erosion of the soil

Sod- grass placed alongside the roadway and drainage structures during phases of construction to prevent erosion of the soil; it is often in conjunction with seeding & mulching

Span- the distance a bridge extends between two supports

Steel- an alloy or iron and carbon that is hard, strong and malleable

Strand Shoe- the device at the end of an eye-bar that holds the wires of each strand for the main suspension cable

Structural Course- lower layers of asphalt used on a roadway.  Often paving projects use more than one layer of structural course

Strut- a piece or member acting to resist compressive stress

Substructure- the parts of a bridge that are below water or land; the piers, or tower foundations, and anchorages

Superstructure- the parts of a bridge that are above water or land—towers, main cables, suspender cables and related parts

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T

Tack- sticky layer of liquid asphalt sprayed on the roadway between new layers of asphalt, which serves as an adhesive

Tension- a stretching force that pulls on a material

Tower- the vertical structure in a cable-stayed bridge that holds up the suspension cables

Turnout- asphalt placed to widen a driveway to make exiting the roadway easier.  It is commonly added to accommodate heavy truck traffic that would have difficulty making a 90-degree turn into a standard driveway

Trestle- a bridge structure consisting of a number of short spans, supported by splayed vertical elements and is usually for railroad use

Truss Bridge- a bridge having a pair of trusses composed of pieces joined together to form a rigid framework

Truss- a rigid frame composed of short, straight pieces joined to form a series of triangles or other stable shapes

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U

Upstream Face- the side of dam that is against the water

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