1AbrasionThe process of wearing away by friction.
2AbutmentA concrete support wall constructed at both ends of a bridge or an arch, in order to resist the horizontal force from the bridge or the arch, support the ends of the bridge span and to prevent the bank from sliding under.
3AcceleratorA substance such as calcium chloride (CaCl2), added in small quantities (max. 0.03% of the cement) to plain concrete to hasten its hardening rate, its set or both.
4AcquisitionThe process of obtaining Right-of-Way.
5Active Earth PressureThe horizontal push from earth onto a wall. The active earth force from sand on to a free retaining wall is equivalent to that from a fluid of density 0.25 to 0.30 times that of the sand. The force from sand on to a fixed retaining wall is very much more.
6Addendum Or AddendaWritten instruments or documents issued prior to the execution of a contract to modify or revise the bidding documents.
7Adhesion Or BondThe sticking together of structural parts by mechanical or chemical bonding using a cement or glue.
8Admixture Or AdditiveA substance other than aggregate, cement or water, added in small quantities to the concrete mix to alter its properties or those of the hard concrete. The most important admixtures for concrete are accelerators, air-entraining agents, plasticizers and retarders.
9Affidavit Of Non-CollusionA sworn statement, by bidders for the same work, that their proposal prices were arrived at independently without consultation or a secret agreement or cooperation for a fraudulent or deceitful purpose between or among them.
10AgentThe person who legally represents the contractor and acts for him on all occasions. He is often a Civil Engineer
11Air-Entrained ConcreteA concrete used for constructing roads. It has about 5% air and is therefore less dense than ordinary good concrete, but it has excellent freeze-thaw resistance. The strength loss is roughly 5% for each 1% air entrained. Air entrained concrete produced by adding an admixture to concrete or cement, which drags small bubbles of air (Smaller than 1 mm in diameter) into the concrete mix. The bubbles increase the workability and allowing both sand and water contents to be reduced.
12Alignment(1) The fixing of points on the ground in the correct lines for setting out a road, railway, wall, transmission line, canal, etc. (2) A ground plan showing a route, as opposed to a profile or section, which shows levels and elevations.
13AppurtenanceAn item which belong with, or is designed to complement something else (For example, a manhole is a sewer appurtenance.)
14ApronA floor constructed along the channel bottom to prevent scour. Aprons are almost always extension of culverts.
15AquiferAn underground source of water capable of supplying a well.
16Arithmetic MeanThe average value which is defined as the sum of all of the observations divided by the number of observations.
17Artesion WellA spring which water flows naturally out of the earth’s surface due to pressure placed on the water by an impervious overburden and hydro-static head.
18Arterial HighwayA general term denoting a highway primarily for through traffic usually on a continuous route.
19As-Built Drawings Or Record DrawingsConstruction drawings revised to show significant changes made during the construction process, usually based on marked-up prints, drawings and other data furnished by the contractor or the Engineer.
20Asphaltic Concrete Friction Course (Acfc)A hot mixture of asphalt cement with an open-graded aggregate (20% to 25% air voids) of a maximum size of 3/8 inch used as a surface (Wearing) course.
21Asphalt Rubber (Ar)A mixture of asphalt cement and rubber used as a crack sealent, binder, or membrane.
22Asphaltic Concrete (Asphalt Rubber)A hot mixture of asphalt cement, rubber, fine and coarse aggregate and mineral admixture mixed together and placed as an asphaltic concrete pavement surface layer. The advantages of this mix are: It stops cracks from reflecting through pavement layers, reduce the riding tires noise and is a useful way to dispose of the used rubber tires.
23Auxiliary LaneThe portion of a roadway adjoining the traveled way for truck climbing, speed change or for other purposes supplementary to through traffic movement.
1BallastCoarse stone or hard clinker, sand or slag carried by a moving unit to keep it held down or to keep equilibrium steady.
2BankA mass of soil rising above a digging level.
3Base CourseOne or more layers of specified materials of designed thickness (Usually asphaltic concrete course), placed on a subbase course or a subgrade to support a surface course.
4Basement MaterialThe material in excavation or embankment underlying the lowest layer of subbase, base, pavement, surfacing or other specified layer which is to be placed on.
5BasinA receptacle for runoff (Storm) water.
6BatterInward slope from bottom to top of a wall face.
7BermAn artificial horizontal ledge in an earth bank or cutting to ensure the stability of a steep side slopes of roadbed (Shoulder). Also berms are built to hold water on land that is to be flood irrigated.
8BeamA horizontal structural member designed to resist loads which bend it.
9Bearing(1) The supporting section of a beam length or area. (2) The compressive stress between a beam and its support (bearing pressure), particularly on foundations. (3) The horizontal angle turned between a datum direction such as true north and a given line.
10Bench MarkA relatively fixed point whose elevation is known and used as a datum for leveling.
11Bending FormulaFormula for beams of any homogeneous material. Moment (M)= Stress X Modulus of Section or (M)= Force X Arm
12Bernoulli EquationIs an Energy equation for two points along the bottom of an open channel experiencing uniform flow.
13BidderAny individual, firm, partnership, corporation, or combination thereof, submitting a proposal for the work contemplated, acting directly or through a duly authorized representative.
14Binder(1) A material such as cement, tar, bitumen, gypsum plaster, lime, or similar material, when mixed with other material, it causes unifomity, consistency, solidification or cohesion. (2) The clay or silt in hoggin or the cement rock. (3) A stirrup or steel rod usually about 6 to 10 mm diameter used for holding together the main steel in a reinforced-concrete beam or column.
15Bituminous Seal CoatA thin bituminous application to a surface or wearing course to seal and waterproof small voids and to embed sand or chips to provide better traction.
16Bleeding Or Flushing(1) Separation of clear water from the cement paste of mortar or concrete. Two types are known, the first beneficial, the second harmful to concrete strength, but they may co-exist. The first occurs during compaction, water can flow out of concrete, lie on its surface, and thus encourage good curing for the first few hours during hot weather. The second type of bleeding occurs after compaction, water segregates beside or under the steel or larger stones, weakening the bond between them and the body of the concrete. A plasticizer should enable the water to cement ratio to be lowered to reduce this type of bleeding. (2) Upward migration of bituminous material resulting in a film of asphalt on the surface.
17BlemishAny imperfection which mars the appearance of wood, concrete, paint or other finished surface.
18BlindingMat or mattress or sealing coat. A layer of lean concrete usually 2 to 4 inches thick, put down on soil such as clay to seal it and provide a clean bed for reinforcement to be laid on.
19BlotterAbsorbant material (i.g., sand) to dry freshly wet surfaces.
20BoringA drilling into the earth to bring up samples of the soil.
21BorrowSuitable material excavated from sources outside the roadway prism (i.g., Borrow Pit), to provide fill elsewhere, primarily for embankment.
22BoulderA rock which is too heavy to be lifted readily by hand.
23BoulevardA wide city street usually planted with shade-trees (Landscaped).
24BridgeA single or multiple span structure, including supports, erected over a depression or an obstruction such as water, a highway or railway and having a track or passageway for carrying traffic.
25Bridge BearingThe support at the bridge pier or abutment, which carries the weight of a bridge.
26Bridge DeckThe load-bearing floor of a bridge, that carries and spreads the loads to the main beams.
27Bridge LengthThe greater dimension of a structure measured along the center of the roadway between backs of abutment backwalls or between ends of the bridge floor.
28Bridge Roadway WidthThe clear width of structure measured at right angles to the center of the roadway between the bottom of curbs or between the inner faces of parapet or railing.
29BypassRoad joining two parts of an older road to avoid a town or village.
1Calendar DayAny day shown on the calendar, and the 24-hour period thereof from 12:01 a.m. to midnight.
2CantileverA beam which is securely supported at one end, and hangs freely at the other; an overhanging beam.
3CamberA slightly arched surface of a road to compensate for anticipated deflection or to allow for drainage.
4Cantilever FootingA combined footing that supports an exterior wall or exterior columns.
5Capillary Pressure Or Seepage ForceIn ground which is being drained from outside an excavation, capillary pressures help the excavated earth to stand steeply. However, if the ground is being drained from inside and not from outside the excavation, the capillary pressures will help the earth face to collapse.
6Capillary WaterWater just above the water table which is drawn up out of an aquifer due to capillary action of the soil.
7CarriagewayThe part of a highway which carrier vehicles.
8CassionA cylindrical or rectangular rigged-wall for keeping water or soft ground from flowing into an excavation while digging for foundations or piles.
9Cast-In-Place Or Cast-In-SituConcrete deposited in its permanent place.
10CaulkingUsing pressure gun for filling of a crack, crevice, seam or joint to make it air or water-tight.
11CementA mixture of silicates and aluminates of calcium that when mixed with water it binds a stone-sand mixture into a strong concrete within a few days.
12Cement MortarMortar usually composed of four parts sand to one of cement, with a suitable amount of water.
13Centerline Or HighwayA line equidistant from the edges of the median separating the main traveled ways on a divided highway, or the center line of the main traveled way on undivided highway.
14ChannelA natural or artificial water course.
15ChainageA length (Usually 100 feet) measured by chain or steel tape.
16Change OrderA written order issued by the Engineer to the Contractor, and signed by both, which set forth any necessary or desirable changes in the contract including, but not limited to, extra work, increases or decreases in contract quantities, the basis of payment, contract time adjustments and other additions or alteration to the contract. A change order signed by the Contractor indicates his agreement therewith.
17CharacteristicA measurable property of a material, product or item of construction.
18ChevronV shaped strips meeting at an angle.
19Chezy Manning EquationUsed to measure water flow in open channels.
20ChromatingPriming with lead or zinc to prevent forming of rust.
21ClayVery fine-grained soil of colloid size(Finer than 0.002 mm), consisting mainly of hydrated silicate of aluminum. It is a plastic cohesive soil which shrinks on drying, expands on wetting, and gives up water when compressed.
22Coarse Aggregate(1) For concrete: aggregate which retained on the No. 4 sieve (4.76 mm). (2) For bituminous material: aggregate which retained on a sieve of 3 mm square opening.
23CobbleRock fragments between 3 to 6 in size.
24Cohesion Of SoilThe stickiness of clay or silt. It is the shear strength of clay, which generally equals about half its unconfined compressive strength.
25Cohesive SoilA sticky soil like clay or clayey silt.
26Cohesionless SoilSand, gravel and similar soils, also known as frictional soils since their properties are defined more by their angle of internal friction than by cohesion.
27CompactionArtificial increase of the dry density of a granular soil by mechanical means such as rolling the surface layers, or driving sand piles for deep compaction, vibroflotation, or impact methods. There are many methods of compaction, six main types of compacting equipment are: (1) pneumatic-tyred rollers, in which the rear wheels cover the gaps left by the front wheels, (2) tamping rollers, (3) sheepsfoot rollers, (4) vibrating rollers, (5) frog rammers (trench compactors), and (6) vibrating plates. The last two are used for confined spaces.
28CompoundA homogeneous substance composed of two or more elements that can be decomposed by chemical changes only.
29ConcreteA mixture of water, sand, stone, and a binder (Usually portland cement) which hardens to a stonelike mass. There are four types of portland cement.
30Normal Portland CementThis is a general-purpose cement used whenever sulfate hazards are absent and when the heat of hydration will not produce objectionable rises in temperature. Typical uses are sidewalks, pavement, beams, columns and culverts.
31Modified Portland Cement (Sulfate-Resistant Portland Cement)This type of cement is applicable when exposure to severe sulfate concentration is expected, generally used in hot weather in the construction of large concrete structures. Its heat rate and total heat generation are lower than for normal portland cement.
32High-Early Strength Portland CementThis type develops its strength quickly. It is suitable for use when the structure must be put into early use or when long-term protection against cold temperatures is not feasible. Its shrinkage rate, however, is higher than for types I and II, and extensive cracking may result.
33Low-Heat Portland CementFor extensive concrete structures, such as gravity dams, low-heat cement is required to minimize the curing heat. The ultimate strength also develops more slowly than for the other types.
34ConduitAny open channel, pipe, etc., for flowing fluid. A pipe or tube in which smaller pipes, tubes, or electrical conductors are inserted or are to be inserted.
35Consistency Of ConcreteEase of flow or workability of concrete, measured by slump test or Kelly ball test.
36ConsolidationThe gradual, slow compression of a cohesive soil due to weight acting on it, which occurs as water, or water and air are driven out of the voids in the soil. Consolidation only occurs with clays or other soils of low permeability, it is not the same as compaction, which is a mechanical, immediate process and only occurs in soils with at least some sand.
37Continuous BeamA beam extending over several spans in the same straight line.
38Continuous Or Combined FootingA long footing supporting a continuous wall or two or more columns in a row.
39ContractorThe person or persons, firm, partnership, corporation, or combination thereof, private or municipal, who have entered into a contract with the State (Client).
40ContractThe written agreement between the State (Client) and the contractor setting forth the obligation of the parties hereunder, including, but not limited to, the performance of the work, the furnishing of labor, equipments and materials and the basis of payment. The contract includes the Advertisement for Bids, Proposal, Bidding Schedule, Contract Agreement and Contract Bonds, Certificate of Insurance, Standard Specifications, Supplemental Specifications, Special Provisions, Project Plans, Standard Drawings and any Supplemental Agreements that are required to complete the construction of the work in an acceptable manner within a specified period, including authorized extensions thereof, all of which constitute one instrument.
41Contract Payment BondThe approved form of security, executed by the Contractor and his surety or sureties, guaranteeing complete performance of the contract and all supplemental agreements pertaining thereto and the payment of all legal debts pertaining to the construction of the project.
42CopingThe cap or top course of a wall.
43CorrosionDisintegration or deterioration of metal, concrete or reinforcement by electrolysis or chemical attack.
44CorrugationsRegular transverse undulation or alternate ridges upon a metal pipe surface to give greater rigidity to thin plates.
45CourseThe roadway horizontal pavement layer.
46CriteriaThe Client’s requirements for the design and construction of a particular type of building, or structure.
47Critical(1) Of, relating to, or being a turning point or specially important juncture. (2) Relating to or being a state in which a measurement or point at which some quality, property or phenomenon suffers a definite change.
48Cracking In ConcreteCracking is always expected in reinforced concrete, since it has such a high shrinkage on hardening. Additional cracks will occur on the stretched side of a beam. Reinforcement shall be inserted sufficient in quantity and closeness to make the cracks invisible to the naked eye and very close together. Contraction and expansion joints are constructed to reduce cracking.
49CrackAn open seam not necessarily extending through the body of a material. There are around 7 types of cracks in asphaltic or portland cement concrete.
50Alligator CrackA crack caused by fatigue of the asphaltic concrete surface layer or excessive movement of the underlying layers. Typically alligator cracks form an interconnected network of irregularly shaped polygons varying in size from a few square inches to 1 square foot.
51Block CrackA crack caused by shrinkage of the bound surface material. Typically block cracks form an interconnected network of nearly square shapes varying in size from 1 square foot to several square feet.
52Durability(D) CrackA series of closely-spaced cracks adjacent and roughly parallel to concrete pavement joints. caused by the freezing and thawing of unsound aggregates that have a high moisture content.
53Random CrackA crack that is neither longitudinal or transverse crack and that has a little or no interconnection with other cracks. May be caused by movement, either of the pavement structure or subgrade or both.
54Reflective CrackCrack in a pavement surface layer caused by the high stresses from movements of a cracked underlying layer.
55Transverse Or Temperature CrackA long crack approximately perpendicular to the centerline caused by longitudinal shortening of the bound surface layer, sometimes called temperature cracks as the shortening is often caused by contraction from temperature changes. Typically transverse cracks extend across the full width of the pavement.
56Craze CrackNumerous fine cracks which appear on the surface of concrete in a hexagonal or octagonal pattern. This type of crack is caused by improperly trowelled concrete surface.
57CulvertA covered channel up to about 12 feet in width or a large pipe for carrying a watercourse below ground level, usually under a road or railway.
58CuringKeeping freshly poured concrete or mortar damp for specified time (Usually the first one week of its life) so that the cement is always provided with enough water to harden. This improves the final strength of concrete, particularly at the surface, and should reduce surface cracking or dusting.
1DadoConcrete barrier on the sides of bridge approach slab; the part of pedestal between cap and base.
2DatumAny elevation taken as a reference point for leveling.
3Deck(1) A flat roof, a quay, jetty or bridge floor, generally a floor form with no roof over upon which concrete for a slab is placed. (2) Formwork for a level surfaces.
4Deformed BarA reinforcing bar with ridges to increase bonding between the reinforcing bar and concrete.
5Density Index (Relative Density):is a measure of the tendency or ability to compact soil during loading. The density index is equal to 1 for a very dense soil; it is equal to 0 for a very loose soil.
6DetourA temporary route for traffic around a closed portion of a road.
7DeviationDifference between the value and the average of a set.
8Diaphragm(1) A stiffening plate in a bridge between the main girders in a bridge or a stiffening web across a hollow building block. (2) Legamentous wall separating two cavities.
9DilutionReducing a concentration of soluble material by adding pure water.
10DistillationSalt removal process from brackish or sea water by boiling and condensation.
11DitchLong narrow excavation for drainage, irrigation or burying underground pipelines.
12Divided HighwayA highway with separated traveled ways for traffic, generally in opposite directions.
13DredgeTo dig or excavate under water.
14DuctA protective tube or a brick or concrete trench or corridor along which pipes or cables pass through the ground.
15DuctilityThe ability of a metal to undergo cold plastic deformation without breaking, particularly by pulling in cold drawing.
16DurabiltyThe ability of materials to resist weathering action, chemical attack, abrasion or other conditions of service.
17Dyke(1) A mound of earth along a river or channel bank to retain floodwater. (2) large ditch. (3) A tabular-shaped igneous intrusion.
1EasementThe right to use or control the property of another for designated purposes.
2Eccentric LoadA load on a column applied at a point away from the column center and therefore putting a bending movement on the column equal in amount to the load multiplied by the arm.
3EfficiencyIt is the power output divided by the power input.
4ElastomerElastic rubber like substance, neoprene, etc.
5EmbankmentA ridge of earth or rock placed, shaped and compacted to carry a road, railway, canal, etc., or to contain water.
6Empirical FormulaA formula or rule based on one or many series of observations or trials, but with no theoretical calculation.
7EmulsionA mixture with water. Asphalt emulsions are produced by adding a small amount of emulsifying soap to asphalt cement and water. When the water evaporates, the asphalt sets.
8EncroachmentThe use of the highway right-of-way for nonhighway structures or other purposes.
9EnergyA capacity for doing work, expressed in work units. Energy may be inherent in the speed of a body (Kinetic energy) or in its position relative to another body (Potential energy).
10EngineerThe State (Client) representative Engineer, acting by and under the authority of the laws of the State (Client). The Engineer is responsible for the Engineering monitoring and checking of construction work progress and conformance to the project specifications requirements.
11EngineeringThe science through which the properties of matter and the sources of power are utilized for man’s benefit.
12Epoxide, Epoxy, Ethoxylene ResinA synthetic, usually two-part material that can set and harden under water or be used for bonding roof bolts or for repairing concrete in heavily trafficked areas, etc.
13ErosionWearing or scouring caused by the abrasive action of moving water or wind.
14ErraticValues which seem to vary excessively from the average.
15ErrorA difference from an average value. An unintentional deviation from correct value.
16Expansion Or Contraciton JoingA gap or space in the steel or the concrete to accommodate both thermal expansion and contraction.
17ExpresswayA divided arterial highway for through traffic with full or partial control of access.
18ExtrapolateTo project tested values, assuming a continuity of an established pattern.
19Extra WorkAdditional construction work for which no price or compensation is provided for in the contract and for which the Contractor is not deemed liable under any other provision of the contract, but found by the Engineer to be necessary or desirable for the satisfactory completion of the contract.
20ExtrusionForming rods, tubes, or sections of specified shape by pushing hot or cold metal or plastics through a shaped die to the required section.
1Factor Of SafetyThe stress at which failure is expected, divided by the design stress (maximum permissible stress).
2FalseworkSupport for concrete formwork or for an arch during construction.
3FatigueThe lowering of the breaking-load of a member by repeated reversals of stress so that the member fails at a much lower stress than it can withstand under static loading.
4FaultingThe difference in elevation of two adjacent concrete slabs at a joint, primarily caused by the traffic-induced movement of base material particles from under one joint edge to under the adjacent joint edge.
5FillEarthwork in embankment or backfilling.
6Fillet3 to 6 inches wide shamfer for column to add beauty and strength by avoiding sharp angels.
7Fillet WeldA weld of roughly triangular cross-section between two pieces at right angles.
8Fine Aggregate(1) Sand or grit for concrete which passes the No. 4 sieve (4.76 mm) and retained in the No. 200 sieve (74 micron or 0.074 mm). (2) Sand or grit for bituminous road-making which passes a sieve of 3 mm square opening.
9Fixed CostsAny necessary labor, material and equipment costs, directly expended on the item or items under consideration which remain constant regardless of the quantity of the work done.
10FlakingPeeling off of the coating.
11Flexible PavementAn asphaltic pavement structure having sufficiently low bending resistance to maintain intimate contact with the underlying structure, yet having the required stability furnished by aggregate interlock, internal friction between particles and cohesion to support traffic.
12FlexureWord meaning bending.
13FlumeA wooden, steel or concrete open channel to carry or measure water flows.
14Fly-AshThe ash which goes to the chimney from pulverized coal and is caught in the fluegas dust extractors. It is used as pozzolan or as an admixture to cement.
15ForceThat which tends to accelerate a body or change its movement (i.g., the weight of a body is a force which tends to move it downwards).
16Formation LevelThe surface level or elevation of the ground surface after all digging and filling, but before concreting.
17FormworkThe wood molds used to hold concrete during the placement and curing processes.
18Foundation FailureFoundations of buildings can fail in one of two ways, first by differential settlement, secondly by shear failure of the soil.
19FreewayA divided arterial highway with full control of access.
20Frictional SoilA clean silt, sand or gravel that is a soil whose shearing strength is mainly decided by the friction between particles. In Coulomb’s equation, sand shear strength is given by the statement S = P tan O, since sand has no cohesion.
21Frontage RoadA local street or road auxiliary to, and located on the side of an arterial highway for service to an abutting property and adjacent areas, and for control of access.
22FrostWeather during which dew is deposited as ice. The danger to construction caused by frost is that water expands by about 9% of its volume when it freezes. Therefore concrete or mortar which have not set and contain free water are disintegrated by it.
23Fusion WeldingThe welding of metals or plastics by any method which involves melting of the edges of the parts to be joined without pressure. Usually a filler rod provides the weld metal.
1GabionsCompartmented rectangular containers made of galvanized hexagonal steel wire mesh and filled with stone. Gabions are used to stabilize and protect embankment slopes from erosion.
2Gantry(1) A temporary staging for carrying heavy loads, such as earth. (2) overhead structure that supports signs, usually built of square timbers or steel joists.
3Geosynthetics (Geomatrix, Geomembrane And Geotextile)Thin fabrics membranes and composites placed between soil layers to prevent sliding and for reinforcing or to retard the migration of clay into the pavement structure or placed between pavement layers for reinforcing or to retard crack propagation from an underlying layer to the one above it.
4GirderA large beam, usually of steel or concrete. Its chords are parallel or nearly so, unlike a truss.
5GoreThe V (Triangular) shaped area immediately beyond the divergence of two roadways bounded by the edges of those roadways.
6GranularMaterial that does not contain more than 35 percent of soil particles which will pass a No. 200 sieve.
7GradingShaping and leveling the ground surface, usually by earth-moving equipments such as graders.
8Gradient Or GradeThe rise or fall per unit horizontal length (Slope) of a pipe, road, railway, flume, etc. Slope also expressed as the number of degrees from the horizontal or as a percentage.
9GravelGranular material retained on a No. 4 sieve (4.76 mm) which is the result of natural disintegration of rock, or untreated or only slightly washed, rounded, natural aggregate, larger than 5 mm.
10GridAny rectangular layout of straight lines (Generally used in locating points on a plan).
11GrillageA footing or part of a footing consisting of horizontally laid timbers or steel beams.
12GroovingThe process of producing grooves in a concrete pavement surface to improve frictional characteristics.
13GroundwaterWater contained in the soil or rocks below the water table. Water table if lowered too much, the ground may settle disastrously.
14Groundwater LoweringLowering the level of groundwater is to ensure a dry excavation in sand or gravel or to enable the sides of the excavation to stand up. Groundwater lowering in this sense is always carried out from outside the excavation either by well-points or from filter wells.
15Grout(1) To fill with grout. (2) Fluid or semi-fluid cement slurry or a slurry made with other materials for pouring into the joints of brickwork or masonry or for injection into the ground or prestressing ducts. Grouting of ducts improves the bond and may reduce corrosion of the tendons but it prevents their inspection and re-tensioning or renewal.
16Gunite, ShoutcreteA cement-sand mortar, thrown on to formwork or walls or rock by a compressed-air ejector, which forms a very dense, high-strength concrete. It is used for repairing concrete surfaces, making the circular walls of preload tanks, protecting wearing surfaces of coal bunkers; covering the walls of mine airways or water tunnels, stabilizing earth excavation slopes and so on.
17Gulley(1) A pit in the gutter by the side of a road. It is covered with a grating. (2) A small grating and inlet to a drain to receive rainwater and wastewater from sinks, baths or basins.
1HeaveUpward movement of soil caused by expansion or displacement resulting from phenomena such as moisture absorption, removal of overburden, driving of piles, frost action, etc.
2HedgeA row of closely planted shrubs forming a fence.
3HighwayThe whole right of way or area which is reserved and secured for use in constructing the roadway and its appurtenances.
4HoneycombingLocal voids or roughness of the face of a concrete structure, caused by the concrete having segregated so badly that there is very little sand to fill the gaps between the stones at this point. Such concrete is weak and should be cut out in a rectangular or square shapes and rebuilt if the wall is heavily loaded.
5HydrationThe combination of water with any substance such as lime or minerals, which is responsible for the alteration of minerals in weathering; the formation of hydrated lime; the setting of cement and so on.
6Hveem’S Resistance Value Test (The R-Value)The R-value is a measure of the ability of a soil to resist lateral deformation when a vertical load acts upon it. The R-value ranges from zero (the resistance of water) to 100 (the approximate resistance of steel). Rvalues of soil and aggregate usually range from 5 to 85.
1ImperviousResistant to movement of water; a description of relatively waterproof soils such as clays through which water percolates at about one millionth of the speed with which it passes through gravel.
2Initial Setting TimeThe time required before a concrete mix can carry a small load without sinking like a mud. This is after about one hour in warm weather.
3Inherent SettlementThe sinking of a foundation due only to the loads which it puts on the soil below it and not to the loads on any nearby foundations. In city sites where the foundations are on clay, all foundations suffer both inherent and interference settlement.
4Interference SettlementThe sinking of a foundation due to loads on foundations near it and the natural extension of their settlement craters beyond their own boundaries.
5Interpolation(1) Inferring the position of a point between known points on a graph by assuming that the variation between them is smooth. Usually the assumption is that the variation is linear (A straight-line variation). (2) To estimate untested values which fall between tested values.
6Invert LevelThe level of the lowest part of a pipe invert.
1Joint SealantA material used as a filler in concrete pavement joints to prevent infiltration of water, soil and other fine particles.
2JoistA horizontal wooden, steel or precast concrete beam directly supporting a floor.
1KeywayA recess or groove in one lift or placement of concrete which is filled with concrete of the next lift, giving shear strength to the joint, also called a key.
2Kinetic EnergyThe energy of a moving body due to its mass and motion. K.E.= W x V / 2 g.
1LaitanceA layer of weak and non-durable cement concrete caused by bleeding as a result of excessive vibration of concrete or over trowelling the mortar. It is weaker than the rest of the concrete and should be cut away and covered with a pure cement wash before laying more concrete on it.
2Landslip Or LandslideA sliding down of the soil on a slope because of an increase of loading (Due to rain, new building, etc.), or a removal of support at the foot due to cutting a railway or road or canal. Clays are particularly liable to slips.
3Lean Concrete Base (Lcb)A mixture of aggregate, cement and water used directly under concrete pavement. The mixture has a lower modulus of rapture than the concrete pavement, and a higher compressive strength than cement treated base.
4LedgeA horizontal projection or cut forming a shelf, cliff or rock wall.
5LimeCalcium oxide (CaO).
6Liquid LimitThe moisture content at the point between the liquid and the plastic states of a clay.
7Liqudated DamagesThe amount prescribed in the contract specifications, to be paid to the State (Client) or to be deducted from any payments due or to become due the Contractor, for each day’s delay in completing the whole or any specified portion of the work beyond the time allowed in the contract specifications.
8Lloyd Davies FormulaA method for calculating the run-off, from which the sizes of sewers are calculated (Runoff water in cubic feet = 60.5 X area drained in acres X rainfall in inches per hour X impermeability factor).
9LoessDeposit of very porous and cavitated wind-blown silt and clay.
10Long ColumnA column which fails when overloaded, by buckling rather than by crushing. In reinforced-concrete work this is assumed to happen when columns which are longer than fifteen times their least dimension.
11Longitudinal JointA joint normally placed between traffic lanes in rigid pavements to control longitudinal cracking.
12Loss Of PrestressLosses of prestressing force after transfer arise mainly through elastic shortening, shrinkage and creep of the concrete and creep of the steel.
13LotAn isolated quantity of material from a single source.
14LuminaireComplete lighting device for the highway.
1MarshesLow lying wet land; swamp.
2MaterialsAny substance specified for use in the construction of the project and its appurtenances.
3Maximum Dry DensityThe dry density obtained by a stated amount of compaction of a soil at the optimum moisture content.
4MeanAn arithmetic mean is an average in which all signs are taken as positive. In an algebraic mean the signs of the quantities are considered and the mean may be either positive or negative.
5MedianThat portion of a divided highway separating the traveled ways for traffic in opposite directions including inside shoulders.
6MembraneA thin film or skin, such as the skin of a soap bubble or a waterproof skin.
7Milling(1) Removing a specified thickness of an existing pavement surface by grinding with a milling machine. (2) Removing metal shavings from a surface by pushing it on a moving table past a rotating toothed cutter.
8MistVery thin fog.
9Moisture ContentThe weight of water in a soil mass divided by the dry weight of the solids and multiplied by 100.
10Moment Carrying Ability Of Reinforced Concrete Beam (Nominal Strength Mn)Mn = Ast. fy [d – 0.59 Ast. fy]/[ fc’b ] or Mn = bd2 fy [1 – 0.59 fy]/ [ fc’ ]
11Monolithic ConstructionConstructed as one piece.
12MortarA paste of cement, sand and water laid between bricks, blocks or stones.
13Movement Joints In ConcreteMovement joints may be of five types, though it is possible for one to combine the properties of one or more others. They reduce or prevent cracking or buckling caused by temperature changes, shrinkage, creep, subsidence and so on. Their location is important. Where possible, they should be placed at points where cracking (or buckling) might start. The five types of joints are: contraction, expansion, hinge or hinged joint, settlement and sliding joints.
14MulchMixes of wet straw and leaf peat.
15MunicipalityCity, town or county.
1Negative MomentA condition of flexture (Bending) in which top fibers of a horizontally placed member (Beam), or external fibers of a vertically placed exterior member (Column), are subjected to tensile stresses.
2NeopreneSynthetic rubber resistant to chemical compound, oil, light, etc.
3Neutral SurfaceIn a beam bent downwards, the line or surface of zero stress, below which all fibres are stressed in tension and above which they are compressed. The neutral axis passes through the center of area of the section (Centroid), if it is of homogeneous material.
1OffsetA horizontal distance measured at right angles to a survey line to locate a point off an edge line.
2Optimum Moisture ContentThat moisture content of a soil at which a precise amount of compaction produces the highest dry density. It is particularly important to achieve this in soil stabilization before the road is completed. It is the percentage of moisture at which the greatest density of a particular soil can be obtained through compaction by a specified method.
3OverburdenMaterial of inferior quality which overlies material of desired quality and which must be removed to obtain the desired material quality.
4OverlayOne or more courses of asphaltic concrete layers placed over existing worn or cracked pavement.
1ParapetAny protective railing, low wall or barrier at the edge of a bridge, roof, balcony or the like.
2ParkwayAn arterial highway for non-commercial traffic, with full or partial control of access, usually located within a park or a ribbon of parklike development.
3Passive PressureA pressure acting to counteract active pressure.
4PavementThe uppermost layer of material placed on the traveled way or shoulders. This term is used interchangeably with surfacing.
5Pavement StructureThe combination of subbase, base course, and surface course placed on a subgrade to support the traffic load and distribute it to the subgrade.
6PeatPlant material partly decomposed by action of water.
7PebblesSmaller pieces of material (0.12 to 0.25 inch minimum size) which have broken away from a bedrock.
8PedestalAn upright compression member whose height does not exceed three times its average least lateral dimension.
9PerforatedPierced with holes.
10PermeabilityThat property of a material which permits a liquid to flow through its pores or interstices.
11Ph ValueAn index of the acidity or alkalinity of a soil in terms of longarithm of the reciprocal of hydrogen ion concentration (e.g., a pH indication of less than 7.0 is acidic, whereas a reading of more than 7.0 is alkaline).
12PierA wide column or a wall of masonry, plain or reinforced concrete for carrying heavy loads, such as a support for a bridge.
13Pier CapThe top part of a bridge pier which uniformly distribute the concentrated loads from the bridge over the pier .
14Pier ShaftThe part of a pier structure which is supported by the pier foundation.
15PileA long slender timber, concrete, or steel structural element, driven, jetted, or otherwise embedded on end in the ground for the purpose of supporting a load or compacting the soil.
16PitAny borrow pit, mine, quarry or surface excavation to obtain sand, clay, gravel, etc.
17PlansThe official project plans and Standard Plans, profiles, typical cross sections, cross sections, working drawings and supplemental drawings, or reproductions thereof, approved by the Engineer, which show the location, character, dimensions and details of the work to be performed. All such documents are to be considered as a part of the plans, whether or not reproduced in the special provisions.
18PlasticityThe property of a soil which allows it to be deformed beyond the point of elastic recovery without cracking or appreciable volume change.
19Plasticity Index (Pi)Numerical difference between the liquid limit and the plastic limit. This is an indication of the clay content on a soil or aggregate.
20Plasticizer Or Water ReducerAn admixture in mortar or concrete which can increase the workability of a mix so much, that the water content can be low and the mortar or concrete strength can thus be increased.
21Plastic LimitThe water content at the lower limit of the plastic state of a clay. It is the minimum water content at which a soil can be rolled into a thread of 1/8 inch diameter without crumbling.
22PlatA small plot of land.
23Portland CementA product obtained by pulverizing clinker consisting mainly of hydraulic calcium silicates. Many different cements now use portland cements or at least contain some, the varieties include: Ordinary, Rapid-hardening, Ultra-high-earlystrength, Portland blast-furnace, Sulphate-resisting and Waterrepellent cements, apart from Colored cements.
24Post-TensioningA method of prestressing concrete in which the cables are pulled or the concrete is jacked up after it has been placed. This method is usual for bridges and heavy structures which are placed in place.
25Potable WaterDrinking water.
26Potential EnergyEnergy due to position such as the elevation head of water or the elastic energy of a spring or structure caused by its deformation.
27PrecisionOf a measurement, the fineness with which it has been read, therefore, precision is different from accuracy.
28Precast ConcreteConcrete beams, columns, lintels, piles, manholes, and parts of walls and floors which are cast and partly matured on the site or in a factory before being placed in their final position in a structure. Where many of the same unit are required, precasting may be more economical than casting in place, may give a better surface finish, reduce shrinkage of the concrete on the site and make stronger concrete.
29PressureA force acting on a unit area.
30PrestressingA process of preparing concrete slabs and beams for extra strength by placing the mix over tightly-drawn special steel wire rope or rods which are later released to provide strong dense concrete. prestressing accomplished by applying forces to a structure to deform it in such a way that it will withstand its working loads more effectively or with less total deflection. When concrete beams are prestressed they deflect upwards slightly by an amount about equal to their total downward deflection under design load. Downward deflection is thus less that half that of a reinforced-concrete beam of the same shape. The struts or braces to deep excavations in bad ground are prestressed to prevent settlement of the surface and damage to neighboring structures.
31Prestressed ConcreteConcrete in which cracking and tensile forces are eliminated or greatly reduced by compressing it by stretched cables, wires or bars within it. Two main methods for prestressing are : post-tensioning and pre-tensioning. Prestressed concrete is economical for spans which are large or where the beam depth must be reduced to a minimum.
32Prime CoatThe initial application of a low viscosity bituminous material to an absorbent surface, preparatory to any subsequent treatment, for the purpose of hardening or toughening the surface and promoting adhesion between it and the superimposed constructed layer.
33Profile GradeThe trace of a vertical plane intersecting the top surface of the proposed wearing surface, usually along the longitudinal centerline of the roadbed. Profile grade means either elevation or gradient of such trace according to the context.
34ProfilographAn instrument for measuring smoothness of a surface (as of metal casting, or a highway or road) by amplification of the minute variations from the plane or arc of smoothness.
35ProjectThe specific section of the highway together with all construction to be performed thereon under the contract.
36ProposalThe offer of a bidder, on the prescribed forms, to perform the work and to furnish the labor, equipments and materials at the prices quoted.
1QuarryAn open pit from which building stone, sand, gravel, mineral, or fill, can be obtained.
1Ramp(1) A steeply sloping road or floor. (2) A connecting roadway between two intersecting highways at a highway separation (3) A short length of drain laid much more steeply than the usual gradient.
2Random SampleA sample selected without bias so that each part has an equal chance of inclusion.
3Rankine TheoryFor dry, cohesionless backfill soil behind retaining walls, the Rankine theory is used to find the vertical and the horizontal (lateral) pressure at any depth, H. The horizontal pressure depends on the coefficient of earth pressure at rest, ko, which varies from 0.4 to 0.5 for untamped sand.
4Rapid-Hardening Or Higl-Early-Strength CementA portland cement which hardens more quickly than ordinary Portland cement and is more costly because it is more finely ground.
5Ravelling Or FrettingProgressive disintegration of a pavement surface through the loss (Breaking away) of aggregate particles from a road surface.
6RavineDeep, narrow cliff or gorge in the earth surface.
7Recycling (Pavement)The re-use of existing pavement materials in a new pavement structure.
8RehabilitationThe improvement of an existing roadway surface by improving the existing surface or by removing (milling) a specified thickness of the existing pavement and placement of additional pavement layers.
9Release Agent Or P Arting Agent Or Parting CompoundA general term that includes any greases, mould oils or sealants, laid over forms or form linings either to ensure a good finish to the concrete, to prevent concrete bonding to forms or to improve the durability of the form or for both.
10Reinforced ConcreteConcrete containing more than 0.6% by volume of reinforcement consisting of steel rods or mesh. The steel takes all the tensile stresses (theoretically). In good design the reinforcement is sufficiently distributed so that the cracks are not conspicuous.
11ResistivityA measure of a substance’s resistance to the flow of electricity through it, expressed in ohm-centimeters. Used on soils to determine coating requirements for new pipe and used to determine the extent of corrosion of existing metal pipes.
12Retarder Or Retarder Of SetAn admixture which slows up the setting rate of concrete.
13Rigid PavementA pavement having sufficiently high bending resistance to distribute loads over a comparatively large area (Portland Cement Concrete Pavement).
14Right-Of-WayA general term denoting land, property of interest therein, usually in a strip, acquired for or devoted to transportation purposes.
15RidgeA long narrow elevation of land.
16RigidityResistance to twisting or shearing.
17RiprapRock used for the protection of embankments, cut slopes, etc., against agents of erosion, primarily water
18RoadbedThe roadbed is that area between the intersection of the upper surface of the roadway and the side slopes or curb lines. The roadbed rises in elevation as each increment or layer of subbase, base, surfacing or pavement is placed. Where the medians are so wide as to include areas of undisturbed land, a divided highway is considered as including two separate roadbeds.
19RoadsideA general term denoting the area adjoining the outer edge of the roadway. Extensive areas between the roadways of a divided highway may also be considered roadside.
20RoadwayThat portion of the highway included between the outside lines of sidewalks, or curbs, slopes, ditches, channels, waterways and including all the appertaining structures and other features necessary to proper drainage and protection.
21Rumble Strip, Serrated Strip Or Jiggle BarA slightly raisedor lowered strip of asphalt, plastic, etc., across the highway traffic lane or along the shoulder lane. Rumple strips are placed together at a spacing (usually one foot) to warn the driver, through an audible warning of the approaching hazard.
22Run-OffThe amount of water from rain, snow, etc., which flows from a catchment area past a given point over a certain period. It is the rainfall less infiltration and evaporation. It can be increased by springs of goundwater or reduced by loss to the ground.
23RusticationHaving the surface rough or irregular, or the joints deeply sunk or chamfered.
24RuttingFormation of longitudinal depressions by the displacement of soils or surfaces under traffic.


1Sagging MomentA bending moment which causes a beam to sink in the middle. Usually described as a positive moment.
2SandGrandular material passing through a #4 sieve (4.76 mm), but predominantly retained above the No. #200 sieve (74 micron).
3Sand EquivalentA measure of the amount of clay contamination in fine aggregate.
4Saturated Surfae Ddry (Ssd)A condition of an aggregate which holds as much water as it can without having any free surface water between the aggregate particles.
5ScalingA delamination of a thin portion of the top of portland. cement concrete.
6Scarifier, Riper Or RooterAn implement which may be self-propelled or towed behind a tractor, with downward projecting tines for breaking a road surface for approximately two feet deep or less.
7Scour Or ErosionRemoval of the sea bed or of a river bed or banks by erosive action of waves or flowing water.
8Screed, Screed Board, Screed Rail Or Tamper(1) A wood or metal templet with which a concrete surface is finished. Screeds are set to the correct level for the slab surface. The screed rail may be cambered but is usually straight. (2) A layer of mortar 2 to 7 cm thick, laid to finish a floor surface or as a bed for floor tiles.
9Sealand Orsealing Compound(1) A fluid of plastic consistency laid over a joint surface or the outside of a joint filler to exclude water. Hot bitumen, rubber strip, plastic strip, hessian caulking, synthetic resins and building mastics are used as sealant. (2) A durable coating of plastics such as epoxy resin or polyurethane, painted on the face of form lining or timber formwork to enable it to be reused many times. (3) Liquid-membrane curing compound. A coating for roads (e.g., bituminous emulsion) over a damp, recently cast concrete surface, which prevents loss of water, and thus ensures proper curing of the concrete. (4) A treatmemt for a set concrete floor which strengthens the concrete surface or binds the aggregate, ensuring that it does not dust. Sodium silicate solution has been successfully used for many years.
10SedimentAny material, mineral or organic matter deposited by water, air, etc., often called silt.
11Septic-TnakUnderground sewage collecting tank.
12Settlement Or SibsidenceDownward movement of a structure such as a railway bridge, dam, or building, due to compression or downward movement of soil below it. It need not be harmful unless different parts settle by different amounts.
13Shear(1) The strain upon, or the failure of a structural member at a point where the lines of force and resistance are perpendicular to the member. (2) The load acting across a beam near its support. For a uniformly distributed load or for any other symmetrical load, the maximum shear is equal to half the total load on a simply supported beam, or to the total load on a cantilever beam. Maximum shear occurs at both ends of a simply supported beam (the acting moment equal to zero near the support’s ends).
14SheathingA sheet metal covering over underwater timber to protect it against marine borers; sheeting.
15Sheet PilesClosely set piles of timber, reinforced or prestressed concrete, or steel driven vertically into the ground to keep earth or water out of an excavation.
16Short ColumnA column which is so short that if overloaded it will fail not by crippling but by crushing.
17ShouldersThe portion of the roadway continguous with the traveled way for accommodation of stopped vehicles, for emergency use and for lateral support of base and surface courses.
18ShovingDisplacement of flexible pavement caused by high shear stresses or because of deficient pavement material.
19ShrinkageThe shrinkage of concrete during hardening can amount to 0.0004 of its length at one year or half this value at two months. Cement mortar shrinks by a similar amount.
20ShutteringThat part of formwork which either is in contact with the concrete or has the form lining attached to it.
21SidewalkThat portion of the roadway primarily constructed for the use of pedestrians.
22SiltGrandular material passing the No. 200 sieve (74 micron), finer than sand but coarser than clay, such particles in the range from 2 to 50 micron. It feels gritty between the fingers but the grains are difficult to see. It can be distinguished from clay by the shaking test or by rolling it into a thread. A thread of silt crumbles on drying, a clay thread does not. Rock flour and loess are materials of silt size.
23SlabA flat, usually horizontal cast concrete member of uniform thickness which extends over three or more supports in a given direction.
24SlagThe waste glass-like product from a metallurgical furnace, which flows off above the metal.
25Slag CementsCements made by grinding blast-furnace slag and mixing it with lime or portland cement or dehydrated gypsum. Slag is also used in making expanding cement and supersulphated cement.
26Slip-FormA narrow section of formwork in slab or wall shuttering that can easily be pulled or raised as concrete in place, and is designed to be removed first, thus making it easy to remove the remaining larger panels. It may also be called a wrecking piece or wrecking strip.
27SlumpThe decrease in height of wet concrete when a supporting mold is removed. It is a measure of consistency of freshly mixed concrete.
28SlurryA thin, watery mixture of neat cement or cement and sand.
29SoilSoil is gravels, sands, silts, clays, peats and all other loose materials including topsoil, down to bedrock.
30Soldier PileAn upright pile used to hold lagging.
31SoundnessResistance to both physical and chemical deterioration.
32SpallingPeeling away of a surface, particularly of portland cement concrete.
33SpanThe distance between the supports of a bridge, truss, arch, girder, floor, beam, etc.
34Spillway Or WastewayAn overflow channel.
35Spread FootingA footing used to support a single column. This is also known as an individual column footing and isolated footing.
36SpecificationsWritten or printed description of construction work to be done forming part of the contract, describing qualities of material and mode of construction, and giving dimensions and other information not shown in drawings. It includes bidding procedures, legal requirements, insurance requirements, material and workmanship requirements, inspection and testing procedures, and procedures for measurement and payment of the work, also the specifications establish obligations of the contracting parties with respect to the State (Client) and his Engineer, it is the obligation to clearly define what is required; to establish a plan for its enforcement to the extent required during the period of execution; and to indicate how the work will be measured and paid for. With respect to the Contractor, it is the obligation of complying with the Contract requirements during the construction period. The Specifications includes Standard Specifications and Special Provisions.
37Special ProvisionsApproved supplementary provisions, additions, revisions or deletions to the standard specifications which may cover conditions peculiar to an individual project.
38Soil StabilizationModification of soils or aggregates by incorporating materials that will increase load bearing capacity, firmness and resistance to weathering or displacement. Common methods are mixing the soil with cement or waste oil or imported soil, also compaction or merely covering with a primer.
39Standard SpecificationsThe current edition of the State’s Standard Specifications for State Road and Bridge Construction.
40Standard DeviationsA measure of variability that can be calculated form the differences between individual measurements in a group and their average.
41Steady FlowFlow which does not vary with time.
42StrandA number of steel wires grouped together by twisting.
43StreetA general term denoting a public way for purposes of vehicular travel, including the entire area within the right-of-way.
44Stress-Absorbing Membrane Interlayer (Sami)A low-stiffness mixture of asphalt cement, rubber and mineral aggregate placed between layers of pavement to retard the transfer of stresses between the layers.
45StructuresBridges, culverts, catch basins, drop inlets, retaining walls, cribbing, manholes, headwalls, buildings, sewers, service pipes, underdrains, foundation drains and other structural features.
46Stripping(1) Loss of binder (Bituminous film) from aggregate particles or from a road surface, due to presence of water. (2) Removing formwork. (3) Clearing a site of turf, brush-wood, topsoil, or the first layer of soil.
47Subbase CourseOne or more layers of specified or selected materials, of designed thickness, placed on the subgrade to support a base course.
48SubcontractorAn individual, partnership, firm, corporation or any acceptable combination thereof, or joint venture, to which the contractor sublets a part of the contract.
49SubgradeThe roadbed materials beneath the pavement structure. The top prepared surface of the subgrade is called finished subgrade elevation.
50SubstructureAll that part of the bridge below the bridge seats, tops of piers, haunches of rigid frames or below the spring lines of arches. Backwalls and parapets of abutments and wing walls of bridges shall be considered as parts of the substructure.
51Subsoil(1) The weather soil directly below the topsoil. (2) The ground below formation level also called the subgrade or foundations.
52Sulphate-Bearing SoilsIf ground water contains more than 0.1% of SO3 or if a clay contains more than 0.5% of SO3, high-alumina cement should be used for all concrete in the ground. Portland pozzolana cement may sometimes give enough protection at lower cost. No precautions needed with foundation concrete in water containing less than 0.02% of SO3 or clay which contains less than 0.1% of SO3.
53SumpA pit in which water or sewage collects before being baled or pumped out.
54SuperelevationExaggerated tilt of roadway on a curve to counteract centrifugal force on vehicles.
55SuperstructureAll that part of a structure above and including the bearing of simple and continuous spans, skewbacks of arches and top of footings of rigid frames, excluding backwalls, wingwalls, and wing protection rails.
56SuretyThe corporate body bound with the contractor for the full and complete performance of the contract and for payment of all debts pertaining to the work.
57SurchargeA surface loading in addition to the soil load behind a retaining wall.
58Surface RecyclingRecycling an existing pavement surface by heating, scarifying (Milling), remixing, rejuvenating with an emulsified recycling agent, placing and compacting.
59Surface WaterWater carried by an aggregate in addition to that held by absorption within the aggregate particles themselves. It is water in addition to saturated surface density water.
60SurfacingThe uppermost layer of material placed on the traveled way, or shoulders. This term is used interchangeably with pavement.
61Surface CourseOne or more layers of specified materials designed to accommodate the traffic load; the top layer of which resists skidding, traffic abrasion and the disintegrating effect of climate. The top layer is sometime called a “wearing course”.
62Swelling PressureThe pressure exerted by a contained clay when it absorbs water. It can amount to considerably more than the pressure of the overlying soil.
1Tack CoatA thin coat of bitumen, road tar or emulsion laid on a road to improve the adhesion of a course above it.
2Tandem RollerA road roller having rolls (drums) of about the same diameter behind each other on the same track.
3Tack WeldA temporary half-inch thick weld that holds steel parts together during fabrication.
4Temperature SteelReinforcement which is inserted in a slab or other concrete member to prevent cracks due to shrinkage or temperature stresses from becoming too large. It generally amounts to a minimum of about 0.1% of the cross-section in any direction. The requirement for a slab, which is two-dimensional, being therefore about 0.2% altogether.
5Temperature StressA stress due to temperature rise or drop. If the expansion due to temperature rise or the contraction due to temperature drop is restrained, the member concerned is stressed in compression during rising temperature or tension during falling temperature.
6TendonA prestressing bar, cable, rope, strand or wire.
7Terzaghi-Meyerhoff EquationThis equation is used to find the gross (ultimate) bearing capacity or gross pressure for a soil:
8ThrustA horizontal force, particularly the horizontal force exerted by retained earth.
9TopsoilThe topmost layer of the soil which by its humus content supports vegetation. It is usually the top one foot of the soil.
10ToleranceAcceptable variation from a standard size.
11ToughnessThe resistance of a material to repeated bending and twisting.
12Torgue, Torsion Or TwistThe twisting effect of a force on a shaft applied tangentially, like the twist on a haulage drum which winds rope on to its circumference.
13Traffic LaneThat portion of a traveled way for the movement of a single line of vehicles
14Travel LaneWhen used to distinguish between passing lane and travel lane, the travel lane is the right lane of a two lane roadway with both lanes going in the same direction. Usually both the passing lane and the travel lane are considered travel lanes with the passing lane considered to be the right travel lane.
15Traveled WayThe portion of the roadway for the movement of vehicles exclusive of shoulders and auxiliary lanes.
16TrussA frame, of steel, but also sometimes of timber, concrete, or light alloy, to carry a roof or bridge, built up wholly from members in tension and compression. It is generally a perfect frame or nearly so, and may be pin jointed.
17TurfingThe covering of an earth surface with growing grass cut from another site. It can also be revetment to slopes which are usually covered by water, made by laying turves on the slope according to a technique like sliced blockwork.
1Uniform FlowFlow which has a constant depth, volume and shape along its course.
2Uplift(1) An upward force on earth due to water leaking into a dam or from any point where water is under high pressure. (2) Lifting of a structure caused by: frost heave, or on the windward side by wind force, or in a dry climate by swelling soil.
1Varried FlowFlow that had a changing depth along the water course. The variation is with respect to location, not time.
2Vibrated ConcreteConcrete consolidated by vibration from an internal or external vibrator. It requires very much less water for effective placing than does concrete compacted by punning, therefore it is much stronger. The formwork, however, must also be stronger when the concrete is to be vibrated. Concrete in hollow-tile floors is not vibrated.
3VibratorA tool which vibrates at a speed form 3,000 to 10,000 rpm and is inserted into wet concrete or applied to the formwork to compact the concrete. Concrete vibrators are of six types: A) For precast work: (1) Platform vibrators, small vibrators carried by one or two men moving up and down a pile or lamp post. (2) Table vibrators, which may vibrate vertically for heavy work or with rotary movement for light pieces. B) For concrete cast in place: (3) Internal vibrators are the best known type. (4) External vibrators are used more in the factory than on the site because of the extra strength required for the formwork. External vibrators are also used for road slabs. (5) A hand screed 12 feet long requires one vibrator, for greater lengths two vibrators are fixed on the screed. C) For very large capacities: (6) Concrete-vibrating machines are used. Vibrators are also used for the compaction of loose soils.
1WarpingDeviation of pavement surface from original profile caused by temperature and moisture differentials.
2Water For Domestic UsePotable water used by the public (Home-use).
3WorkThe product of a force and the distance through which it moves. It is to be distinguished from energy and from power which is a rate of doing work. Energy can, however, be expressed in the same units as work, and often is.
4Work On Engineering ContractsWork here shall mean the furnishing of all labor, materials, equipment and other incidentals necessary or convenient to the sucessful completion of the project and the carrying out of all the duties and the obligations imposed by the contract.
5WeepholeA hole to allow water to escape from behind a retaining wall and thus to reduce the pressure behind it.
6WorkabilityThe ease with which a concrete can be mixed, placed and finished. Wet concretes are workable but weak. Workability can be measured by the slump test, the compacting factor test, and by the V.-B. Consistometer test.
1XylemThe botanical name for wood.
1Yield Or BuckleThe permanent deformation which a metal piece undergo when it is stressed beyond its elastic limit.


1ZonningRestrictions as to size or character of buildings permitted within specific areas, as established by urban authorities.