PCD-A1

7/25/2019 PCD-A1

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50 TERMS USED IN PRE – STRESSED CONCRETE DESIGN

Anchorage device - The hardware assembly used for transferring a post-tensioning force from the

tendon wires,strands or bars to the concrete.

Anchorage Seating - Deformation of anchorage or seating of tendons in anchorage device whenprestressing force is transferred from jack to anchorage device.

Anchorage Spacing - Center-to-center spacing of anchorage devices.

Anchorage one - The portion of the structure in which the concentrated prestressing force istransferred from the anchorage device into the concrete ( ocal !one", and then distributed more widelyinto the structure (#eneral !one" ($rticle %.&'.'".

!a"ic Anchorage Device - $nchorage device meeting the restricted bearing stress and minimum platestiffness re uirements of $rticles %.&'.).&.& through %.&'.).&.*+ no acceptance test is re uired for asic$nchorage Devices.

!onded Tendon - restressing tendon that is bonded to concrete either directly or through grouting.

Ca#$e Shear - ertical component of a prestress force which is inclined to the hori/ontal. 0sed in shearcalculations and generally reduces the effects of applied shear forces.

Coating - 1aterial used to protect prestressing tendons against corrosion, to reduce friction betweentendon and duct, or to debond prestressing tendons.

Contin%o%" &or 'ive 'oad" - 1ulti-span structure utili/ing precast-prestress units with a castin-placedeck. The top slab is reinforced across the bents thereby making the structure, 2continuous for live loads.23ee $rticle 4.4.5, Design of an 262 #irder Continuous for ive oad.

Contin%o%" Str%ct%re - 1ulti-span structure constructed continuous over several spans withoute7pansion joints.

Co%p$er" (Co%p$ing") - 1eans by which prestressing force is transmitted from one partial-lengthprestressing tendon to another.

Creep o& Concrete - Time-dependent deformation of concrete under sustained load.

C%rvat%re *riction - 8riction resulting from bends or curves in the specified prestressing tendonprofile.

De#onding (#$an+eting)- 9rapping, sheathing, or coating prestressing strand to prevent bondbetween strand and surrounding concrete.

Diaphrag, - Transverse stiffener in girders to maintain section geometry.

D%ct - :ole or void formed in prestressed member to accommodate tendon for post-tensioning.

Edge Di"tance - Distance from the center of the anchorage device to the edge of the concretemember.

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E&&ective Pre"tre"" - 3tress remaining in concrete due to prestressing after all calculated losses have

been deducted, e7cluding effects of superimposed loads and weight of member+ stress remaining inprestressing tendons after all losses have occurred e7cluding effects of dead load and superimposedload.

E$a"tic Shortening o& Concrete - 3hortening of member caused by application of forces induced byprestressing.

End Anchorage - ength of reinforcement, or mechanical anchor, or hook, or combination thereof,beyond point of /ero stress in reinforcement.

End !$oc+ - ;nlarged end section of member designed to reduce anchorage stresses.

*riction (po"t-ten"ioning) - 3urface resistance between tendon and duct in contact during stressing.

Genera$ one - <egion within which the concentrated prestressing force spreads out to a more linearstress distribution over the cross section of the member (3aint enant <egion" ($rticle %.&'.&.'".

Gro%t Opening or .ent - 6nlet, outlet, vent, or drain in post-tensioning duct for grout, water, or air.

/inge C%r$ - 0nwanted deflection of the cantilever portion of a hinged span caused by application ofthe full prestress force to the member in its unloaded state.

Inter,ediate Anchorage - $nchorage not located at the end surface of a member or segment+ usuallyin the form of embedded anchors, blisters, ribs, or recess pockets.

ac+ing *orce - Temporary force e7erted by device that introduces tension into prestressing tendons.

'ight1eight Concrete - 0nit weight of concrete that is='&> lb per cu ft.

'oca$ one ?The volume of concrete surrounding and immediately ahead of the anchorage device,subjected to high local bearing stresses ($rticle %.&'.&.&".

'o"" o& Pre"tre"" - <eduction in prestressing force resulting from combined effects of strains inconcrete and steel, including effects of elastic shortening, creep and shrinkage of concrete, rela7ation ofsteel stress, and for post-tensioned members, friction and anchorage seating.

Nor,a$ 1eight Concrete - 0nit weight of concrete that is@ '*> lb. per cu ft.

Partia$ Pre"tre""ing - Technology wherein the structure is designed with a combination of prestressingsteel andmildsteel reinforcing. 3ee 2$Design rocedure for artial restressing of Concrete o7 #irder

ridges2 by 3teven . 1c ride dated Aanuary 45, '%B).

Po"t-Ten"ioning - 1ethod of prestressing in which tendons are tensioned after concrete hashardened.

Preco,pre""ed one - ortion of fle7ural member cross-section compressed by prestressing force.

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Pre"tre"" *ra,e - That portion of a continuous structure between e7pansion joints to be prestressedfor it s total length.

Pre"tre"" Path - Trace ofprestressing tendon throughout the length of the member.

Pre"tre""ed Concrete - <einforced concrete in which internal stresses have been introduced toreduce potential tensile stresses in concrete resulting from loads

Preten"ioning - 1ethod of prestressing in which tendons are tensioned before concrete is placed.

Pre"tre"" Shortening - ;lastic and inelastic shortening of a member due to the application of theprestressing force.

Pre"tre"" Mo,ent - 1oment resulting from the eccentricity of the prestress tendon.

Re$a2ation o& Tendon Stre"" - Time-dependent reduction of stress in prestressing tendon at constantstrain.

Re"%$tant Mo,ent - The resulting moment due to prestressing is the algebraic sum of the primary andsecondary moments.

Secondar3 Mo,ent - 1oment resulting from induced reactions atthesupports of a prestressedcontinuous member. The term 2secondary2 is somewhat misleading since the moments are not alwayssecondary in magnitude and therefore play an important part in the stresses along the member.

Shear 'ag - on-uniform distribution of bending stress over the cross section.

Shrin+age o& Concrete - Time-dependent deformation of concrete caused by drying and chemicalchanges (hydration process".

Specia$ Anchorage Device - $nchorage device whose ade uacy must be proven e7perimentally in thestandardi/ed acceptance tests of Division 66, 3ection '5.4.&.4.

Tendon - 9ire, strand, or bar, or bundle of such elements, used to impart prestress to concrete.

Tran"&er- $ct of transferring stress in prestressing tendons from jacks or pretensioning bed to concretemember.

Tran"&er 'ength - ength over which prestressing force is transferred to concrete by bond inpretensioned members.

4rapping or Sheathing - ;nclosure around a prestressing tendon to avoid temporary or permanentbond between prestressing tendon and surrrounding concrete.

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50 S M!O'S USED IN PRE – STRESSED CONCRETE DESIGN

$s E area of non-prestressed tension reinforcement

$Fs E area of compression reinforcement

$Gs E area of prestressing steel

$sf E steel area re uired to develop the compressive strength of the overhanging portions of the flange

$sr E steel area re uired to develop the compressive strength of the web of a flanged section

$v E area of web reinforcement

b E width of flange of flanged member or width of rectangular member

bv E width of cross section at the contact surface being investigated for hori/ontal shear

bF E width of a web of a flanged member

C<c E loss of prestress due to creep of concrete

C<s E loss of prestress due to rela7ation of prestressing steel

D E nominal diameter of prestressing steel

d E distance from e7treme compressive fiber to centroid of the prestressing force, or to centroid ofnegative moment reinforcing for precast girder bridges made continuous

dt E distance from the e7treme compressive fiber to the centroid of the non-prestressed tensionreinforcement

;3 E loss of prestress due to elastic shortening

e E base of aperian logarithms

fcds E average concrete compressive stress at the c.g. of the prestressing steel under full dead load

fcir E average concrete stress at the c.g. of the prestressing steel at time of release

fFc E compressive strength of concrete at &B days

fFci E compressive strength of concrete at time of initial prestress

fct E average splitting tensile strength of lightweight aggregate concrete, psi

fd E stress due to unfactored dead load, at e7treme fiber of section where tensile stress is caused by

e7ternally applied loads

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fpc E compressive stress in concrete (after allowance for all prestress losses" at centroid of cross

section resisting e7ternally applied loads or at junction of web and flange when the centroid lies within theflange (6n a composite member, fpc is resultant compressive stress at centroid of composite section, or at junction of web and flange when the centroid lies within the flange, due to both prestress and momentsresisted by precast member acting alone."

fpe E compressive stress in concrete due to effective prestress forces only (after allowance for allprestress losses" at e7treme fiber of section where tensile stress is caused by e7ternally applied loads

fps E guaranteed ultimate tensile strength of the prestressing steel, $GsfFs

fr E the modulus of rupture of concrete

Hfs E total prestress loss, e7cluding friction

fse E effective steel prestress after losses

fGsu E average stress in prestressing steel at ultimate load

fFs E ultimate stress of prestressing steel

fsy E yield stress of non-prestressed conventional reinforcement in tension

fFy E yield stress of non-prestressed conventional reinforcement in compression

fGy E yield stress of prestressing steel ($rticle %.'>" E 5.%5 fFs for low-rela7ation wire or strand

E 5.B> fFs for stress-relieved wire or strandE 5.B> fFs for Type 6 (smooth" high-strength barE 5.B5 fFs for Type 66 (deformed" high-strength bar

h E overall depth of member

6 E moment of inertia about the centroid of the cross section

I E friction wobble coefficient per foot of prestressing steel

E length of prestressing steel element from jack end to point 7

1cr E moment causing fle7ural cracking at section due to e7ternally applied loads

1Gcr E cracking moment

1dJc E composite dead load moment at the section

1dJncE non-composite dead load moment at the section

1ma7 E ma7imum factored moment at section due to e7ternally applied loads

1n E nominal moment strength of a section

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1u E factored moment at section K 1n

p E $sJbdt, ratio of non-prestressed tension reinforcement

pF E $FsJbd, ratio of compression reinforcement

u E factored tendon force

L E statical moment of cross-sectional area, above or below the level being investigated for shear,about the centroid

M E friction curvature coefficient E total angular change of prestressing steel profile in radians from jacking end to point 7 E factor for concrete strength

NG E factor for type of prestressing steel E 5.&B for low-rela7ation steel E 5.*5 for stress-relieved steel E 5.>> for bars

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60 ENG'IS/ 7 TAGA'OG TERMS USED ON SITE

Ani$3o (3tirrup" - $ reinforcing device to resist shear and diagonal tension stresses in a beam.

A"intada - Concrete :ollow locks aying $lignment

!a$ang+a" (8ramework" - $n assemblage of structural elements or members fitted together to form a

structure, as a multistory building, a rigid-frame shed, or a truss. !iga ( eam" - $ structural member that is fabricated from metal, reinforced or prestressed concrete, wood, fiber-reinforced plastic, or other construction materials and that resists loads perpendicular to itslongitudinal a7is

!i"agra (:inge" - $ movable joint used to attach, support, and turn a door (or cover" about a pivot+consists of two plates joined together by a pin which support the door and connect it to its frame, enablingit to swing open or closed.

De !andeha ( aneled Door" - $ door having a framework of stiles, rails, and muntins which form oneor more frames around thinner recessed panels.

G%i$i$an (#irder" - #irder is the term used to denote the main hori/ontal support of a structure whichsupports smaller beams. $ girder is commonly used many times in the building of bridges, and planes.

/a,#a (DoorJ9indow Aamb" - $ door jamb (also sometimes doorjamb or doorpost" is the verticalportion of the frame onto which a door is secured.

/ardinera (3tringer" - $n inclined member supporting the treads and risers of a staircase.

/%$og ( lumb obJ lumb ine" - $ plumb-bob or a plummet is a weight, usually with a pointed tip onthe bottom that is suspended from a string and used as a vertical reference line, or plumb-line.

'adri$3o (Cement rick" - $ type of brick made from a mi7ture of cement and sand, molded underpressure and cured under steam at &55O8 (%4OC"+ used as backing brick and where there is no danger ofattack from acid or alkaline conditions.

'arga Ma"a (3lab" - That part of a reinforced concrete floor, roof, or platform which spans beams,columns, walls, or piers.

Pa$itada ( lastering" - laster is a building material used for coating walls and ceilings. laster starts asa dry powder similar to mortar or cement and like those materials it is mi7ed with water to form a paste which liberates heat and then hardens.

Pie De Ga$$o (Diagonal race" - $n inclined structural member in compression andJor tension+ usuallyemployed to stabili/e a frame against hori/ontal forces, such as wind.

Pierno ( olt" - $ rod, usually of metal, with a s uare, round, or he7agonal head at one end and a screwthread on the other, used to fasten objects together.

Pi$arete (3tud" - $ vertical member of appropriate si/e (&2 7 *2 to *2 7 '52" (or >5 mm 7 '55 mm to '55mm 7 &>5 mm" and spacing ('P2 to 452" (or *55 mm to )>5 mm" to support sheathing or concrete forms

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60 ENG'IS/ 7 TAGA'OG TERMS USED ON SITE

Re#ocada (3cratch Coat" - The first coat of plaster or stucco applied to a surface in three-coat workand usually cross-raked or scratched to form a mechanical key with the brown coat.

Reo"tra ( urlin" - $ hori/ontal roof beam, perpendicular to the trusses or rafters+ supports the roofingmaterial or the common rafters.

Si#e (;aves" - Those portions of a roof that project beyond the outside walls of a building.

S%$era" (Aoist" - $ joist is one of the hori/ontal supporting members that run from wall to wall, wall tobeam, or beam to beam to support a ceiling, roof, or floor.

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PCD-A1