Post-tensioning

Sa Carneiro airport, Porto (Portugal)

Tensacciai started to operate in the field of post-tensioning in 1956 and in the sixties the beginning of the highway program in Italy offered many chances in the works of art, favoring in this way a remarkable development of the Company.The systems used by Tensacciai were those of partial tensioning. These systems were soon considered insufficient to the owner to face competition of simultaneous tensioning systems.A program of technological renewal began. 0,6” diameter strands started to be used, and the system of multiple and simultaneous tensioning was developed.The use of strand, at that time scarcely present in post-tensioning, made it possible to carry out a system of multiple tensioning which, by assuring the isotensioning to cable components under stressing, complied with a design requirement, not yet achieved by the other systems with the same efficaciousness.An important development was achieved in the seventies: the years of the completion of the big highway program in Italy and of the final success of Tensacciai, as the system universally became used in big public works and in the most important bridges.During the nineties Tensacciai has completely streamlined and innovated its technological and operating structure and has fully developed the electrically insulated post-tensioning system.Moreover, during year 2008 Tensacciai has finally obtained the European Technical Approval and subsequent CE marking for its post-tensioning system after 3 years of intensive testing campaign in several European laboratories.Post-tensioning tendons have been installed in several jobsites in all five continents, in wider applications in viaduct, bridges, tanks, buildings and foundations.

Tensacciai post-tensioning system

Multi-strands tendons foresee a wide range of anchorages and systems for different applications.Post-tensioning system is provided with European Technical Approval and CE marking.

MTAIthe MTAI monogroup anchorage range is now improved and completed.In fact, the MTAI system, with its compact geometry and reduced angle of deviation, is the most modern, high-performance Tensacciai development comprising also a dead anchorage type MTAIM.

MTGcoupling anchorage has been developed and improved, covering the full range of post-tensioning tendons.

MTAIEexternal post-tensioning anchorage

MTAIDelectrically insulated anchorage, widely used and tested in the world’s biggest full scale application, the 4,3 km long Piacenza viaduct.

The production also includes the ST series anchorages, i.e. dead end anchorages with bond end anchorages, CU single strand coupling type, and the DF anchorage used for ring post-tensioning or for intermediate tensioning.Systems are also foreseen for the slab post-tensioning: the 1C15 monostrand unbounded system and the multi-strand bonded PTS system.

As a specialized contractor with decades of experience in the specific field, Tensacciai is able to provide not only the products and the installation but also, through their Engineering Department, all the activities involved in design, such as shop drawings, assistance to design, installation procedures, tension checking and other engineering services related to the installation of post-tensioning works.Tensacciai take care of all the placing, stressing, tension and deformation checking operations with their own specialized teams, taking full responsibility and applying Quality Assurance according to ISO9001.

Steel strand

(notations according to prEN10138-3, in rounded brackets to ETAG013 where possible)

Other typologies of strands are available on request, according to main international standards.

This document provides technical information regarding post-tensionig tendons made of strands 15,7 (0,6”S) or 15,2 mm (0,6”) diameter.

(1) Until prEN10138-3 remains a draft norm, standards and regulations valid at the place of installation can be used.(2) The requirement for 70% Fm is mandatory.(3) Values for 80% Fm may be agreed between supplier and purchaser.

Dimension and properties of 7-wire strands according to prEN 10138-3 (1)

Steel name Y1860S7 Y1860S7

Tensile strength Rm (fpk) [MPa] 1.860 1.860

Diameter D [mm] 15,7 15,2

Cross sectional area Sn (Ap) [mm2] 150 139

Mass M [g/m] 1.172 1.086

Permitted deviation on nominal mass [%] ± 2

Characteristic value of maximum force Fm (Fpk) [kN] 279 259

Maximum value of maximum force Fm – max [kN] 329 306

Characteristic value of 0,1% proof force Fp0.1 (Fp0,1k) [kN] 246 228

Minimum elongation at maximum force Agt (L0 ≥ ) [%] 3,5

Relaxation after 1000 hours at 0,7 Fm (2) [%] 2,5

at 0,8 Fm (3) [%] 4,5

Modulus of elasticity E [MPa] 195.000

Tendons can also be made of 12,7 mm (0,5”) diameter strands: this system is less used but still available in Tensacciai product range.

Ducts

Suggested technical data

Strand no. 4 7 9 12 15 19 22 27 31 37

Internal Ø [mm] 45 62 72 80 85 95 100 110 115 130 Grout requirement

[l/m] 1,2 2,3 2,8 3,6 3,8 4,7 5,2 6,2 6,9 8,6

Cement [kg/m] 1,9 3,6 4,5 5,8 6,1 7,5 8,4 9,9 10,8 13,8

Duct thickness vary from 0,3 up to 0,6 mm on request.These dimensions are indicative only: in any case they must comply with national standards and be in accordance with operating conditions.

Ducts are made of bright or galvanized steel or plastic. The ducts have a corrugated surface to guarantee the adherence between the cable and the surrounding concrete.

Main features of cables using 15,7 mm strand

Strand diameternominal cross section area 140 mm2

nominal mass 1.093 g/m

Number of strands 4 7 9 12 15 19 22 27 31 37

Nominal cross section area of steel Ap [mm2] 556 973 1.251 1.668 2.085 2.641 3.058 3.753 4.309 5.143

Nominal mass of steel [kg/m] 4,24 7,60 9,77 13,03 16,29 20,63 23,89 29,32 33,66 40,18

Characteristic tensile strength fpk = 1.860 MPa

Characteristic ultimate resisting force of tendon Fpk [kN] 1.036 1.813 2.331 3.108 3.885 4.921 5.698 6.993 8.029 9.583

Main features of cables using 15,2 mm strand

The maximum prestressing force to be applied on the tendon is specified in the national standards and regulations in force in the place of use.

Strand diameternominal cross section area 150 mm2

nominal mass 1.172 g/m

Number of strands 4 7 9 12 15 19 22 27 31 37

Nominal cross section area of steel Ap [mm2] 600 1.050 1.350 1.800 2.250 2.850 3.300 4.050 4.650 5.550

Nominal mass of steel [kg/m] 4,69 8,20 10,55 14,06 17,58 22,27 25,78 31,64 36,33 43,36

Characteristic tensile strength fpk = 1.860 MPa

Characteristic ultimate resisting force of tendon Fpk [kN] 1.116 1.953 2.511 3.348 4.185 5.301 6.138 7.533 8.649 10.323

High speed train line Roma Napoli, Colleferro (Italy)

Tensacciai post-tensioning systemTensacciai post-tensioning systemMTAI system, with its compact geometry andreduced deviation angle, is a guarantee for highperformance, both for internal and externalpost-tensioning systems.

Removable grouting cap

Hdpe connector

Metallic or PE duct

Cast iron block

MT anchor plate

MTG system is the range of anchorages suitable for the coupling of cables. It is fully integrated with the MTAI system and allows installation of cables in different separate stages.

MTG anchor plate

Spring

Wedges

Steel connector

Metallic or PE duct

Internal MTAI type

Post-tensioning system rangePost-tensioning tendons anchorages are classified in live anchorages, dead anchorages, couplers, annulars, external and electrically insulated.

Internal MTAIM type

Electrically insulated MTAID type

Coupler MTG type

External MTAIE type

Annular DF type

Post-tensioning systemCenter and edge distance

MTAI system size 4 7 9 12 15 19 22 27 31 37

Minimum edge distance (A) [mm] not including cover

fcm,0 - cyl = 25 MPa 125 165 190 220 250 280 305 340 365 410

fcm,0 - cyl = 33 MPa 110 145 165 195 220 245 265 300 325 360

fcm,0 - cyl = 45 MPa 95 130 144 170 190 215 230 260 280 310

Minimum center distance (B) [mm]

fcm,0 - cyl = 25 MPa 270 355 400 465 520 580 630 700 755 840

fcm,0 - cyl = 33 MPa 240 315 355 410 460 515 555 620 670 740

fcm,0 - cyl = 45 MPa 210 280 315 360 405 450 485 540 585 640

C’ - concrete cover in accordance with European Standard EN 1992-1-1 and national regulations valid at the place of use

Bursting reinforcement

MTAI system size 4 7 9 12 15

Concrete strength 25 33 45 25 33 45 25 33 45 25 33 45 25 33 45

fcm,0 – cyl [MPa]

Φs [mm] 200 170 150 250 210 180 290 260 230 340 310 280 380 350 315

Φb [mm] 10 12 12 14 14

SL [mm] 250 225 200 360 300 270 420 360 330 480 420 360 510 450 420

p [mm] 50 60 60 60 60

No. of turns 5 4,5 4 6 5 4,5 7 6 5,5 8 7 6 8.5 7,5 7

MTAI system size 19 22 27 31 37

Concrete strength 25 33 45 25 33 45 25 33 45 25 33 45 25 33 45

fcm,0 – cyl [MPa]

Φs [mm] 410 380 360 470 430 400 500 470 440 540 500 470 560 530 500

Φb [mm] 16 16 20 20 20

SL [mm] 570 510 450 660 540 480 720 600 540 750 630 570 780 720 630

p [mm] 60 60 60 60 60

No. of turns 9,5 8,5 7,5 11 9 8 12 10 9 12,5 10,5 9,5 13 12 10,5

MTAI system size 4 7 9 12 15 19 22 27 31 37

LTOT [mm] 475 531 688 708 736 783 823 848 1.009 1.107

S [mm] 150 180 200 220 250 280 300 325 350 400

h [mm] 45 49 52 62 69 74 80 87 91 96

hm [mm] 77 84 84 92 98 106 110 115 122 131

d (int/ext) [mm] 45/50 62/67 72/77 80/85 85/90 95/100 100/105 110/115 115/120 130/135

MTAIM system

MTAI system

MTG system size 4 7 9 12 15 19 22 27 31 37

A [mm] 185 215 230 248 265 280 340 340 390 430

B [mm] 90 100 105 104 110 120 120 120 140 150

C [mm] 330 380 400 430 460 460 600 600 730 815

D [mm] 100 120 180 190 208 225 240 250 300 360

E x E [mm] 150 180 200 220 250 280 300 325 370 400

F [mm] 45/50 62/67 72/77 80/85 85/90 95/100 100/105 110/115 115/120 130/135

MTG coupler system

MTAID systemElectrically insulated post-tensioning

MTAID anchorages for electrically insulated post-tensioning meet the demand for totalprotection of pre-stressing cables from corrosive agents. This protection is total andpermanent, since the cable is enveloped completely in a protective sheath from outsideagents, starting from the anchoring blocks. Protection by envelopment consists ofdielectric material made of high-density polyethylene that covers the strands also in theanchoring areas.In this post-tensioning application, the anchoring discs of the strands are separated from thecast-iron blocks of the ends by means of rings made of dielectric material capable ofwithstanding the prestressing effort without becoming deformed.The polyethylene connectors that are positioned inside the cast-iron blocks lead out from theseparating rings; then they are connected to the sheaths by means of elements that makethe system completely waterproof.

Electrically insulated post-tensioning systemoffer measurable advantages:

•electricalinsulationofthecablefrom the surrounding environment; protection against corrosion caused by electrochemical phenomena;• impermeabilityoftheduct; protection against corrosion caused by oxidation and chlorides attack;•totalfillingofpipeswithmortarinjection;•possibilityofcontrolduringstructurelifetime of the integrity of protection with electrical resistance measures;•useofspecialsheathsHDPE; reduction of friction losses.High speed train

line Milano Napoli, Piacenza viaduct, Piacenza (Italy)

MTAID system size 4 7 9 12 15 19 22 27 31 37

A [mm] 150 180 200 220 250 280 300 325 370 400

B [mm] 100 120 180 190 206 225 240 250 300 360

C [mm] 110 140 160 180 200 220 250 270 290 310

D [mm] 45 47 48 51 53 65 74 78 88 94

E [mm] 90 90 90 90 95 100 110 115 125 135

F [mm] 280 324 348 378 428 418 478 478 538 568

G [mm] 58/73 58/73 76/91 76/91 100/116 100/116 100/116 115/131 130/146 130/146

MTAIE system External post-tensioning

through the presence of an inner steelcone that separates strands and inner protective injection from the surrounding elements in the anchorage zone.

Is Tensacciai external-post-tensioning evolution, suitably designed for external cables where full replaceability and protection is required.System can be demounted and substituted

MTAIE system size 4 7 9 12 15 19 22 27 31 37

A [mm] 150 180 200 220 250 280 300 325 350 400

B [mm] 100 120 180 190 208 225 240 250 300 360

C [mm] 135 160 177 195 210 245 265 295 330 330

D [mm] 63/3,6 75/4,5 90/5,4 110/6,6 110/6,6 125/7,4 125/7,4 140/8,3 160/9,5 160/9,5

E [mm] 310 360 430 450 520 600 660 700 750 800

F [mm] 82,5 101,6 127 139,7 152,4 168,3 193,7 203 229 229

MTRN systemAdjustable post-tensioning

The great advantage of this system is to allow force adjustment anytime, depending on the structure behaviour and construction needs.It also gives the possibility to monitor loads, especially in the period following the installation of cables, when either the strands relaxation or the viscous effects of concrete can affect the evaluation of forces.To allow the load check and adjustment, Tensacciai can provide MTRN anchorages, composed of a threaded anchorage with a nut, all protected with a cap filled with grease. The load adjustment operation is carried out with a special annular jack, especially designed for these applications. This system is fully replaceable.Due to the progressive deterioration of already built structures, now the technique of external post-tensioning is becoming more common

during last years, especially in the cases where it’s necessary to increase considerably the resistance of load-bearing beams.On request Tensacciai can supply complete monitoring systems, with load cells and data recording with alert system.

Protection cap Protection tubeBearing plate

Compound sealing

Injection pipe

Galvanized greased and coated strand

NutAnchorplate MTRN Type

Anti-corrosive compound

Salerno - Reggio Calabria Highway, rehabilitation of Incoronata viaduct, Polla (Italy)

CU coupling system

CU system size 4T15 7T15 9T15 12T15 15T15 19T15 22T15 27T15

(7T13) (9T13) (12T13) (15T13) (19T13) (22T13) (27T13)

A [mm] 675 800 950 1250 1.250 1.300 1.385 1.700

B [mm] 45/50 62/67 72/77 80/85 85/90 95/100 100/105 110/115

C [mm] 140 159 177 193 193 193 219 244

D [mm] 300 340 400 400 400 400 400 400

E [mm] - - 800 800 800 800 800 600

F (mm) - - - 1.200 1.200 1.200 1.800 1.400

ST dead end system

ST system size 4 7 9 12 15 19

A [mm] - 80 - 80 - -

B [mm] 210 240 - 400 - -

C [mm] 80 - 160 160 160 240

D [mm] 80 - 160 160 160 240

E [mm] 10 10 12 14 14 14

F [mm] 50 50 60 60 60 70

G [mm] 250 350 400 400 400 400

H [mm] 800 800 800 800 800 900

I [mm] 100 100 150 150 150 220

DF systemAnnular post-tensioning

Special rectangular anchorages are used for ring post-tensioning: these anchorages also uses a special deviator for tensioning with mono-strand jacks.

Additional sizes available on requestDF system size 2 4 6 8 12

A [mm] 85 90 110 115 120

B [mm] 55 60 80 85 90

C [mm] 90 100 140 150 160

D [mm] 100 160 230 320 400

E [mm] 70 80 100 130 160

F [mm] 560 710 860 950 1200

G [mm] 170 200 240 300 330

H [mm] 140 170 210 270 300

Derivation tunnel for hydroelectric plant, Presenzano (Italy)

Malampaya off shore gravity structure, Olongapo (Philippines)

Post-tensioning system for buildings

Monostrand system (1C15)

•Strandsarecoveredwithaspecial corrosion inhibitor grease and with a proof PE coating•Noadherencebetweenductandconcrete•Highperformanceinserviceconditions(SLS)•Possibilitytomaximizecableseccentricity•Rapidityofexecutionandcracking phenomena reduction

Multistrand system (PTS)

•Strandsareallinsertedinsideaduct, that is filled with cementious material after installation•Highperformancebothinservice(SLS) and ultimate conditions (ULS)•Multistrandsystemwith5strands maximum

Unbonded Bonded

Strands used main characteristics

Steel designation Y1820S7G Y1860S7 Y1860S7

Diameter [mm] 15,2 15,2 15,7

Ultimate strength [MPa] 1.820 1.860 1.860

Area [mm2] 165 139 150

Maximum load [kN] 300 259 279

PTS systemslab post-tensioning

PTS system size 3-13 3-15 4-13 4-15 5-13 5-15

(3 strands Ø 12,7 mm) (3 strands Ø 15,2 mm) (4 strands Ø 12,7 mm) (4 strands Ø 15,2 mm) (5 strands Ø 12,7 mm) (5 strands Ø 15,2 mm)

A [mm] 170 170 220 220 220 265

B [mm] 75 75 75 75 75 75

C [mm] 50 60 50 60 50 60

D [mm] 125 155 160 205 200 250

E [mm] 190 190 220 220 220 270

F [mm] 45 45 45 45 45 45

G [mm] 45 45 45 45 45 45

H [mm] 72 72 72 72 72 92

I [mm] 20 20 20 20 20 22

1C15 systemSlab post-tensioning

Live end

Dead end

Coupler

Plant for San Benedetto mineral water, Treviso (Italy)

A [mm] B [mm] C [mm] D [mm]

180 140 80+c 60+c

Center and edge distances valid for fcm,0 – cyl ≥20 MPa

c - concrete cover in accordance with European Standard EN 1992-1-1 and national regulations valid at the place of use

Calculation notes

Friction losses

The calculation of loss of prestressing force due to friction and wobble effects inside tendons is usually made starting from the following equation, taken from EN 1992-1-1:

where:ΔPμ (x) = loss of prestressing force from 0 up to x distance [kN]x = distance from the stressing point [m]Pmax = force at the stressing end [kN]μ = friction coefficient between strands and ducts [1/rad]θ = sum of the angular deviation from 0 up to x distance, irrespective of direction or sign [rad]k = not intentional angular deviation inside tendons, wobble coefficient [rad/m]Values for friction coefficient μ are between 0,18 and 0,22 while k values are between 0,005 and 0,01.Recommended values for calculation are μ = 0,19 [1/rad] and k = 0,005 [rad/m].

ΔPμ (x) = Pmax (1-e-μ(Θ+kx))

Basic elongation evaluation factors

The elongation of the tendon, under the action of one or two jacks, is determined by the designer and verified at the construction site. The elongation calculation must clearly specify the theoretical elongation calculation and the corrective elements taken into account. It must be possible, with great accuracy, to establish the relationship between calculated elongation and measured elongation. In fact, secondary terms should be added to the elongation of the tendon along its length up to the anchorages, to obtain the real elongation.Real elongation measured at the construction site is thus defined as the sum of the following elements:

•DLa:theoreticalelongationofthestrand, calculated on the basis of the length between the anchorages, at one or two ends, depending on whether one or two jacks are used. •DLb:concreteelasticshortening. This bit of information, since it is extremely small, is usually neglected.•DLr:accumulationofdeformationsofthe anchorage devices, for the deflection of the anchorages into the concrete and for the draw-in of the wedges.•DLv:draw-inofthestrandwedgeswithin the jack and jack deformations.

DLo = DLa + DLb + DLr + DLv

Equipments

Together with post-tensioning system Tensacciai has developed a range of dedicated installation equipments, including multi and mono stressing jacks, hydraulic pumps, grouting pumps and load cells.Nowadays Tensacciai is proudly involved in design and production of new stressing jacks, applying technologies and experience to obtain even more performing equipments.

Tensioning of vertical cables

PT seriesmonostrand stressing jacks

Tensacciai manufactures 4 type of “PT” series jacks which differ in terms of tensioning section, weight and dimensions. All the jacks of the “PT” series are equipped with the automatic lock-off.

Type of jack PT 150 KN PT 200 KN PT 250 KN PT 300 KN

Capacity [kN] 150 200 250 300

Stroke [mm] 100 200 200 200

Weight [kg] 16 23 23 28

Tensioning section [cm2] 32,80 47,20 47,20 58,32

Max. tensioning pressure [bar] 550 450 550 550

Max. return pressure [bar] 180 180 180 180

Max. locking pressure [bar] 165 165 165 165

Connection [cm2] 2 tubes 2 tubes 2 tubes 2 tubes

A [mm] 85 100 97 110

B [mm] 600 1000 930 870

C [mm] 60 85 77 88

MT seriesmulti strand stressing jacks

Tensacciai manufactures several types of “MT” stressing jacks (monogroup), ranging from 1000 up to 9000 kN. The “MT” jacks have been designed and built by Tensacciai considering stressing needs: minimum strand waste, jack built-in hydraulic circuit, controlled lock-off, easily removed and controlled wedges, jack rotation around its own axis, making easier to place and wedge onto the tendon. The extreme high functionality and material based quality have made of this jacks’ series its success even under the most severeoperating conditions.

Type of jack MT1000KN MT1500KN MT2500KN MT3000KN MT3500KN MT4500KN MT6000KN MT9000KN

Capacity [kN] 1.000 1.500 2.500 3.000 3.500 4.500 6.000 9.000

Stroke [mm] 250 250 250 250 250 250 250 250

Weight [kg] 100 180 290 350 420 600 1.000 1.250

Tensioning section [cm2] 155,51 302,18 361,00 400,55 492,44 725,71 879,60 1.400,50

Max. tensioning pressure [bar] 600 500 700 700 700 700 700 700

Max return pressure [bar] 180 180 180 180 180 180 180 180

Max. locking pressure [bar] 165 165 165 165 165 165 165 165

Tensioning overlength

with lock-off [cm2] 35 37 37 38 38 45 51 52

A [mm] 950 930 951 984 970 1.107 1.237 1.016

B [mm] 155 130 150 154 148 200 207 195

C [mm] 137 152 173 195 214 243 295 322

D [mm] 162 185 213 236 252 310 380 407

E [mm] 248 310 339 370 415 512 615 714

Detailed technical sheets and instruction manual are available on request.

Type of jack MT1000KN MT1500KN MT2500KN MT3000KN MT3500KN MT4500KN MT6000KN MT9000KN

Capacity [kN] 1.000 1.500 2.500 3.000 3.500 4.500 6.000 9.000

Stroke [mm] 250 250 250 250 250 250 250 250

Weight [kg] 100 180 290 350 420 600 1.000 1.250

Tensioning section [cm2] 155,51 302,18 361,00 400,55 492,44 725,71 879,60 1.400,50

Max. tensioning pressure [bar] 600 500 700 700 700 700 700 700

Max return pressure [bar] 180 180 180 180 180 180 180 180

Max. locking pressure [bar] 165 165 165 165 165 165 165 165

Tensioning overlength

with lock-off [cm2] 35 37 37 38 38 45 51 52

A [mm] 950 930 951 984 970 1.107 1.237 1.016

B [mm] 155 130 150 154 148 200 207 195

C [mm] 137 152 173 195 214 243 295 322

D [mm] 162 185 213 236 252 310 380 407

E [mm] 248 310 339 370 415 512 615 714

MTX seriesmultistrand stressing jack

Foto corretta?

Type of jack MTX2500KN MTX3500KN MTX4500KN

Capacity [kN] 2.500 3.500 4.500

Stroke [mm] 100 100 250

Weight [kg] 350 420 600

Tensioning section [cm2] 409,00 564,22 636,43

Max. tensioning pressure [bar] 660 660 660

Max return pressure [bar] 100-120 100-120 100-120

Max. locking pressure [bar] 100-120 100-120 100-120

Tensioning overlength with lock-off [cm2] 23 26 26

A [mm] 650 665 680

B [mm] 150 160 165

C [mm] 180 214 255

D [mm] 305 347 400

E [mm] 390 466 537

The “MTX” series jacks, as natural evolution of the “MT” series jack, have been designed and built for stressing in very restricted areas, where the overall round dimensions of the jack are fundamental factor.

MTP seriesmultistrand stressing jack

Type of jack MTP850KN MTP1600KN MTP2600KN MTP3500KN MTP5500KN MTP7000KN

Capacity [kN] 850 1.600 2.600 3.500 5.500 7.000

Stroke [mm] 150 250 250 250 250 290

Weight [kg] 95 195 258 665 570 1200

Tensioning section [cm2] 194,78 278,02 549,78 674,49 987,30 1.237,00

Max. tensioning pressure [bar] 465 570 485 495 497 560

Max return pressure [bar] 200 200 200 200 200 200

Max. locking pressure [bar] 100 100 100 100 100 100

Tensioning overlength with lock-off [cm2] 500 750 880 1.200 1.300 1.500

A [mm] 493 780 900 1.170 1.124 1.281

B [mm] 217 165 195 285 217 323

C [mm] 136 170 227 225 256 320

D [mm] 146 218 270 291 336 396

E [mm] 230 280 375 417 496 560

MTP series jack is the last evolution of Tensacciai stressing equipment. This series has been designed during last year after a long experience of many years on jobsites all around the world, and guarantee top efficiency level during installation.

Pumps and equipment

Stressing pump

Tensacciai offers a wide range of hydraulic pumps, which differ in terms of performance ratings, dimensions and weight. The “PT” series jacks require stressing pumps with power ratings ranging between 2.2 and 10 kW. The MT, MTX and MTP series jacks require stressing pumps with power ratings ranging between 7.5 and 30 kW. All Tensacciai pumps are equipped withan automatic lock-off circuit.

Grouting pump

The “GP” pump is available in various models which differ in terms of performance ratings.The grouting pump consists of an eccentric screw pump, a mixer and a turbomixer. All the machines are equipped with a push-button control panel.

Vacuum pump

Tensacciai offers vacuum pumps with power ratings ranging from 4 kW to 7.5 kW.This pump is used to inject grout under a vacuum, thus guaranteeing perfect grouting without any air entrance.

Strand pushing machine

This equipment, designed to insert the prestressing strands into the sheaths, consists of a hydraulic pump and a unit that pushes the strand into the sheath. The two units can be installed at a remote location.Tensacciai also offers various models to meet all construction site requirements.

Bond end machine

The equipment consists of an automatic pump XST/3” and an operating unit (jack UST/3”) that opens the strand. The bond end operation is completely automatic,controlled by an electronic device that regulates both time and force.

Extrusion jack

The equipment consists of a highpowered portable jack (XG2), fed by a hydraulic pump. This jack extrudes passive anchorages(compression grips) at the ends of the strands.The jack drive will vary depending on the type of pump to which it is connected.

Post-tensioning bars

Products

Tensacciai supplies bars with continuous thread for post-tensioning applications, such as buildings, roads and viaducts, tunnels and mines. These systems can be provided in diameters varying from 12 to 75 mm, and are used worldwide in post-tensioning and in pre-tensioning systems application.The advantages in the use of these post-tensioning systems are several and are supported by excellent results achieved in various jobsite.Usable for all reinforcing systems, different corrosion protection systems and steel grades are available.

•Easeofhandlingon-site.•Continuesthreadalongtheentirelengthofthe bar, which ensures optimal adhesion with the cast in concrete.•Cuttosizeandpossibilityofextension using couplers in any position of the bar.•Differentpossibilitiesforprotectionagainst corrosive phenomena: galvanized, hot dip galvanized, epoxy coated, painted acc. DV-Norm. For special applications further steel grades are available.

Application field

•Prestressedconcretestructures•Rehabilitationofbuildings•Temporarysupports

Nut

Coupler

Threaded bar

Bearing plate

Steel barscarachteristics

SAS 670

Continuous threaded barleft hand thread hot rolled, ribbed

Continuous thread barsright hand, hot rolled Y 1050

ft = minimum ultimate strengthFt = minimum ultimate loadAgt = percentage total elongation at maximum forceA = areaA10 = ultimate elongation evaluated on 10 diameters

d [mm] 18 26,5 32 36 40 47 57 65 75

max dA [mm] 21 31 37 42 46 53 64 72 82

fy/ / fpk / A10 950 N/mm² / 1050 N/mm² / 7 % 835N/mm²/1035 N/mm² / 7%

Fpk [kN] 255 580 850 1.070 1.320 1.820 2.671 3.447 4.572

A [mm²] 241 551 804 1.020 1.257 1.735 2.581 3.331 4.418

d [mm] 18 22 25 28 30 35 43 57,5 63,5 75

max dA [mm] 21 25 28 32 34 40 48 63 70 82

fy / ft / A10 670 N/mm² / 800 N/mm² / 10%

Ft [kN] 195 300 390 490 565 770 1.170 2.080 2.540 3.535

A [mm²] 250 375 491 616 707 962 1.466 2.597 3.167 4.418

Accessories

Several kind of accessories are available to satisfy all design requirements. Full range set of couplers, nuts and anchor plates, including special pieces could be realized on request.

Tensacciai is able to provide a wide range of products customisation which enablesuse in new and different shapes.

N° Coating ID thickness Reference code bar length

1 spray galvanization GV m = 8±2m DIN 50961 on request

2 hot galvanization FV m = 100±20m DIN EN ISO 1461 on request

3 epoxy coating EP m = 200±50m ASTM A 934 / A 934M 15 mt

ASTM A 775 / A 775M

Anticorrosion protection

Metallic end cap are always placed when it is necessary to provide a protective injection in the anchorage zone.

Tenso-inox

When it is necessary to ensure a long life service to the structure, even if it is exposed in a particularly aggressive environment, and also a high resistance to corrosion and fatigue with high mechanical strength and ductility is required, TENSO-INOX systems can be used: modern systems with a wide range of use. Developed to meet the demand for solutions with high mechanical characteristics.

Nominal diameter [mm] Area [mm2] Breaking load Ft [kN]

20 320 329

22 387 398

24 461 475

26 541 557

28 627 646

32 819 843

36 1.035 1.066

38 1.156 1.190

40 1.280 1.318

50 1.985 2.044

Tenso-Inox 1030 SS

That is why we provide the indications necessary to design for the most appropriate applications. Tenso-inox bars are made of special stainless steels by process of hot rolling, according to EN 10088 / 3 standards and certified according to EN 10204 3.1.B.Tenso-inox bars are manufactured throughhot rolling process, in special high resistanceand high yield strength steels, with resilience at -20 ° C> = 27 J.

Different typologies of accessories available

Installation

Placing of the steel sheaths

The sheaths are fixed to the reinforcing steel of the structure to avoid that their position changes during the pouring of the concrete. For longitudinal post-tensioning they are usually placed following a parabolic lay-out.

Threading of the strands

Strands are thread one by one inside the placed duct, using special strand pushing machine. Threading operation shall be carried out with care to avoid any damage to the strand or to the steel duct.

Tensioning

Tensacciai jacks have been designed and built considering stressing needs: minimum strand waste (300mm to 500mm), automatic lock-off, easy removal and control of the wedges, jack rotation around its own axis.

Grouting

Grouting of tendon ducts shall be executed using a colloidal cement mortar, with a composition variable depending on temperature and length of tendons. Tendons ducts shall be provided with air vent pipes at the highest parts to ensure the air gets out and grout completely fills internal volume. Grouting equipment consist of an eccentric screw pump, a mixer and a turbo mixer.

Bridges

High speed train line Milano Napoli, Piacenza viaduct, Piacenza (Italy)Electrically insulated post-tensioning

High speed train line Milano Torino, Marchiazza viaduct, Vercelli (Italy)Electrically insulated post-tensioning

Bridges

Imigrantes Highway, San Paolo-Santos (Brasil)

Metro project, Dubai (UAE)

Bridges

Central corridor, Muscat (Oman)Tiziano bridge, Alessandria (Italy)

Funchal airport extension, Madeira (Portugal)

Bridges

Rabat – Fes Highway, section 2 (Morocco)

Adriatic LNG project Mooring Dolphins, Venezia (Italy)

Bridges

Loureiro viaduct, Calhandriz (Portugal)

Metro railway viaduct, Delhi (India)

Bridges

Covas viaduct, Galizia (Spain)

Head Office:via XX Settembre, 2420123 Milano (Italy)tel. +39 024300161fax +39 0248010726info@tensacciai.it

Office in Rome:via Lutezia, 200198 Roma (Italy)tel. +39 0632111820fax +39 063219854tensroma@tensacciai.it

Factory:via 25 Aprile, 8/1020016 Pero, Milano (Italy)tel. +39 0238100064fax +39 0233910227tenspero@tensacciai.it

www.tensacciai.it