TTM Slab Bonded and Unbonded Systems

Slab, Bonded and unbonded Post-Tensioning System – Rev. B 1

Use of post-tensioning technologies in modern structures

Today’s building owners and designers need to provide a high level of structural flexibility to meet changing user requirements. Post-tensioning provides greater spans with reduced structural beam depths, resulting in larger column-free areas. As a result, internal layouts are not dictated by tight column grids. Positive deflection and crack control and, if necessary, joint-free slabs, free designers from the limitations of conventional reinforced concrete structures.

Our Unbonded Slab Post-Tensioning System has been used in many buildings and structures. The system foresees strands individually stressed and gripped by wedge action.


Supply of cut tendons with passive pre locked anchorage Bonded and greased mono strand tendons can be supplied, rolled and equipped with pre locked anchorage, directly from TTM. This kind of provision reduces activities on site.

Properly cut Tendons for 1EX15 pre locked anchorage at one edge

Cut tendons equipped with 1EX15 pre locked anchorage

Tendons have 1EX15 pre locked anchorage in one edge. They have rear protection joint which will be positioned on site. Tendons are strapped and protected by slices of paper.


Monostrand Post-tensioning The commercial building segment, including: hotels office towers and condominiums, benefit from a weight reduction from thinner slabs. Furthermore, post-tensioning allows earlier stripping of formwork shortening overall construction time. .

For cast-in place parking structures, it is the improved ride and architectural lighting advantages that are main benefits over precast design. Tendons for slab-on-ground provide a virtually crack-free slab for high durability with direct exposure to expansive soils, groundwater and contaminated run-off .

Our Monostrand system uses 0.6" (15,2mm) diameter strands with compact cross area (165mm2). The strands are given a coating of permanent corrosion-inhibiting coating and are enclosed in an extruded plastic sheath. The grease and plastic provide double corrosion protection, as well as preventing any bonding between the strands and the surrounding concrete.

The plastic sheath is polyethylene with approximately 50 mil wall thickness. To ensure continuous corrosion protection in aggressive environments, special sleeves are used to join the sheaths to the anchorages and each anchorage is provided with a protective cap.


Our Monostrand System features factory-applied corrosion protection, very low friction losses, and full utilization of the structural depth. These light, flexible monostrands can be easily and rapidly installed, leading to economical solutions.


1. Introduction

1.1. General Post-tensioning technology has for many yeas occupied a very important position in the construcion of bridges and storage tanks. The reason lies in its decisive technical and economical advantages. The more important advantages, offered by post-tensioning, may be briefly recalled here:

• By comparison with reinforced concrete, a considerable saving in concrete and steel quantities since, due to the working of the entire concrete cross-section more slender design are possible.

• Smaller deflections than with steel and reinforced concrete.

• Good crack behaviour and therefore permanent protection of the steel against corrosion.

• Almost unchanged serviceability even after considerable overload, since temporary cracks close

again after the overload has disappeared.


• High fatigue strength, since the amplitude of the stress changes in the post-tensioning steel under alternating loads

In addition to the already mentioned general features of post-tensioned construction, the following advantages of post-tensioned slabs over reinforced concrete slabs may be listed as it follows:

- More economical structures resulting from the use of post-tensioning steels with a very high tensile strength instead of normal reinforcing steels;

- Larger spans and greater slenderness. The latter results in reduced dead load, which also has a

beneficial effect upon the columns and foundation and reduces the overall height of buildings of a given height (Fig.2);

- Under permanent load, very good behaviour in respect of deflections and cracking;

- Higher punching shear strength obtainable by appropriate layout of tendons.

This kind of technology is very advantageous to build rectangular slabs with sides 6 –10 metres long. The design of these slabs are foresees the use a mesh of mono-strand cables (0.6”) with 165mm2 cross section area.

The shape of the cables follows the spatial funicular of semi dead load, it has held in the thickness of the reinforced concrete slab and the anchorages at the border are placed in central position fixed to the boundary.


Semi dead load is obtained adding the whole dead load and half of live load. In these conditions the slab has subjected to axial force without bending moment and shear force.

If the live load is lower than 30% of total load, calculus is statically determinate because the bending moment is produced only by +/- the half of live load The compressive stress in slabs with may varies between 1,5 and 2,5 N/mm2.

The advantages obtained using this kind of technology are:

1. It isn’t necessary an automatic calculus, either for complicated structures; 2. Semi dead load didn’t generate bending moment on pillars and walls, therefore the bending reserve of

these elements are available to withstand the horizontal loads; 3. Slabs are perfectly plane with beams’ depth contained in their thickness and they maintain a plane

shape because of the absence of bending foliage;


4. Floors are waterproof because cracks are absent;

5. After 2-3 day from casting it is possible stress the structure ( Rck>150 Kg/cm2 ), 6. By the striking of formwork real slabs and the immediate re-assembling of the formwork for the

subsequent slab the testing of the floors is easily obtained; 7. The surface of the intrados may have a finish that does not need further workings. 8. ; 9. It is easy to make holes while projecting; however, facility is kept after the projecting phase

also if it is not necessary to cut the strands 10. adopting some precautions it is possible to extend the drilling to the spaces near the pillars and

put in axis 11. This kind of structure is usually safer than traditional ones, The structure is less sensitive to

imprecision of construction; therefore, a qualified personnel is required only during the stressing operations. (1 or 2 people).


1.2 - Post-tensioning with or without bonding of tendons

1.2.1 - Bonded post-tensioning As is well-known, in this method of post-tensioning, the post-tensioning steel is placed in ducts, and after stressing is bonded to the surrounding concrete by grouting with cement suspension. Rounded corrugated ducts are normally used. For the relatively thin floor slabs of building, the reduction in the possible eccentricity of the post-tensioning steel with this arrangement is, however, too large, in particular at cross-over points, and for this reason flat ducts have become common


1.2.2 - Unbonded post-tensioning In the early stages of development of post-tensioned concrete in Europe, post-tensioning without bond was also used to some extent After a period without any substantial application, some important structures have again been built with unbonded post-tensioning in recent years.

In the first application in USA, the post-tensioning steel was grassed and wrapped in wrapping paper, to facilitate its longitudinal movement during stressing.

During the last few years, however the method described below for producing the sheathing has generally become common. The strands is first given a continuous film of permanent corrosion preventing grease in a continuous operation, either at the manufacturer’s works or at the post-tensioning firm.

A plastic tube of polyethylene or polypropylene of at least 1mm wall thickness is then extruded over this. The plastic tube forms the primary and the grease the secondary corrosion protection. Strands sheathed in this manner are known as monostrands (fig. 3). The nominal diameter of the strands used is 15mm (0.6”).


1.2.3 - Bonded or unbonded ? This question was and still is frequently the subject of serious discussion. The subject will not be discussed in detail here, but instead only the most important arguments far and against will be listed:

Comparazione delle eccentricità che possono essere ottenute con diversi tipi di cavi


Argument in favour of post-tensioning without bonding.

- Maximum possible tendon eccentricities, since tendon diameter are minimal; of special importance in thin slabs (see Fig.4);

- Post-tensioning steel protected against corrosion ex works; - Simple and rapid placing of tendons; - Very low losses of post-tensioning force due to friction; - Grouted operation is eliminated; - In general more economical

Arguments in favour of post-tensioning with bonding.

- Larger ultimate moment; - Local failure of a tendon (due to fire, explosion, earthquakes etc.) has only limited effects.


2 – LOSSES CALCULATION ELEMENTS AND EVALUATION OF ELONGATIONS

It is necessary to distinguish the shrinkages of tensioning as immediate shrinkages or deferred shrinkages for the correct execution of calculations.

2.1 – Immediate lossees Eurocode 2, 5.10.3

The 5.10.3 (3) paragraph of the European norm UNI EN 1992-1-1:2005 (EC2) recommends to consider the following immediate post-tensioning influences, if applicable, for determining the immediate losses

1. losses due to the friction strand/sheath

2. losses due to the anchorage return (wedge draw-in), 3. lossess due to elastic deformation of piling,

Immediate shrinkages appear during the post-tensioning, reducing the tension generated by the hydraulic jack.

2.1.1 – Tensioning shrinkages due to friction Eurocode 2, 5.10.5.2

Complying with the EC2, 5.10.5.2 , tension shrinkages ( )xµσ∆ in post tensioning due to the friction

can be estimated from:

( )xµσ∆ = ( ) )1(max,kx

Po e +−− θµσ

Where:

->It is the sum of angular displacements over a distance x (regardless of direction or sign);

- It is the fiction coefficient between strand and sheath [rad-1];

- It is a non intentional angular deviation for internal strands (per unit length, rad/m);

x - It is the distance along the strand from the point where pre-stressing force is equal to Pmax

(the force at the active end during tensioning). The value µ depends on the characteristics of the strand and the sheath, on the presence of rust, on the elongation of the tendon and on the tendon profile. The k value for unintentional displacement depends on the quality of workmanship, on the distance between tendons supports, on the type of sheath or duct employed, and on the degree of vibration used in placing the concrete. TTM recommends the following values of µ and k :

µσ∆slσ∆

elσ∆

θ

k

µ


- monostrand viplato ed ingrassato (Sheath HDPE):

0,05 rad-1 < < 0,07rad-1 e 0,004 rad/m < k < 0,008 rad/m - bonded monostrand in galvanized sheath:

= 0,19 rad-1 e k=0,005 rad/m

2.1.2 – Losses due to wedge draw-in Eurocode 2, 5.10.5.3

During the blocking of the wedges in the anchoring, the loss of elongation of the strand is damped by friction with the sheath; this is opposite to what happens during stressing phase. When using parabolic cable, losses due to attrition are constant along the cable itself:

l

kl

lP )(max,0 +

≅∆ θµσσ µ

where: l is the length of strand The reduction of stress, which reaches its higher value near the active anchorage device, progressively and symmetrically decreases and ceases at a certain distance “d” from the anchorage.

Stress losses after wedges draw-in

where: c is the length of strand subjected to wedges draw-in

In TTM post-tensioning system, wedges draw-in, during post-tensioning application, causes a reduction of the strand elongation of mml 5=∆ .

µ

µ


Losses at the origin (on the active anchorage) are:

cl

xslµσ

σ∆

==∆ 2)0(

l

AElc pp

µσ∆

∆=

where: c is the length of strand subjected to wedges draw-in. Losses in section cx ≤ are:

)(2)0( xcl

xsl −∆

==∆ µσσ

2.1.3 – Losses of stress due to elastic deformation of concrete Eurocode 2, 5.10.5.1

Losses of stress due to elastic deformation of concrete are often negligible; however, in a section with “n” post- tensioning strands, deformation of concrete during stressing operations causes deformation of the element under stress and shortening of the already stressed tendons.

This shortening corresponds to a loss of post-tensioning, which may be approximately calculated by the following expression:

PcPcm

Pel At

tE

E

n

n)(

)(2

1 σσ ∆−=∆


where: n number of strands EP is the modulus of elasticity for the prestressing strand Ecm is the modulus of elasticity for the concrete

)(tcPσ∆ is the variation of stress in strands the centre of gravity of the tendons of post-tension at

time t

2.2 – Evaluation of elongations during strands stressing operations During stressing operations it is necessary to compare the actual elongations with the theoretical expected elongation to which should be added corrections to obtain real elongations. Elongations reported in site are the sum of the following elements:

ao LL ∆=∆ + bL∆ + cL∆ + dL∆ + eL∆

where:

aL∆ is the elongation of strand calculated by considering the extra-length necessary for the

hydraulic jacks seize;

bL∆ is the elastic deformation of concrete. The measured elongation usually includes the

elastic shortening of concrete;

cL∆ is the sum of deformations of anchorage devices and wedges draw-in;

dL∆ is the wedge draw-in;

eL∆ is the internal deformation of the hydraulic jack.

2.2.1 – Wedges draw-in on active anchorages Loss of elongation due to wedge draw-in occurs during the anchoring operations after tensioning In accordance with “Static Load Tests, EMPA” reports, dL∆ is valuated in this way:

= 5 mm for stressing by hydraulic jack equipped with anchors

= 10 mm for stressing by hydraulic jack non equipped with anchors

dL∆

dL∆


2.2.2 – Wedges draw-in and deformation on fixed anchorage In accordance with “Static Load Tests, EMPA” reports, anchorages deformations under stress always are imitated and never exceed 1mm. Wedges draw-in on passive anchorages corresponds to a translation of the tendon towards the hydraulic jack. The reported values are about 4-5 mm.

2.2.3 – Hydraulic jacks deformation These deformations are gathered from the elongation of strands when the evaluations are taken from the piston of the hydraulic jack. Internal losses of hydraulic jacks are considered:

TTM Hydraulic jack = 8 mm Elongations directly obtained from strands should not be considered.

2.2 – Stressing values of post-tensioning anchorage in strand 2.3 Ministerial decree, 14 January 2008

Technical norms for calculation, execution and test of structures made of reinforced concrete, normal

and pre-stressed and for metallic structures.

Maximum stress applicable on a strand

Maximum stressing force has to be limited at:

Pspi = 0,85 x fp(0,1)k x Ap e Pspi = 0,75 x fptk x Ap (t=0)

spσ = 0,60 x fptk (t=∝)

where: Pspi is the maximum stress in the time t=0

spσ is the stress on a strand at time t= ∞

fp(0,1)k is the characteristic 0,1% proof-stress of pre-stressing steel fptk is the breaking stress Ap is the cross-sectional area of the strand


2.4 – Stressing values on post-tensioned anchorages in strand

Eurocode 2, 5.10.3

In accordance with 5.10.3(2) of EC2, the value of the beginning pre-stressing force Pm0(x) (at time t = t0) from the anchorage immediately applied after tensioning, is obtained subtracting from force Pmax, at the time of stressing, the immediate losses ∆Pi(x),

The beginning force should not exceed the hereafter value:

Pm0(x)=Ap x max,Pσ∆

max,Pσ∆ = min {0,75 fpk; 0,85 fp0,1k}

where: Pm0 is the beginning pre-stressing force (t=t0)

max,Pσ∆ è la tensione nell’armatura subito dopo la messa in tensione

fpk is the breaking stress fp0,1k is the stress at 0,1% residual deformation

2.5 – Limitation of concrete tension

EC2, 5.10.2.2

Concrete tension, caused by stressing force and further loading forces involved in the stressing phase, should be limited at:

σc ≤ 0,6 fck(t ) Where: fck(t) Is concrete tension in time t when it is submitted top re-stressing force. If Tension of stressing permanently exceeds 0,45 fck(t ), the non linearity viscosity must be considered. A gradual stressing of each single can reduce the required concrete resistance. The minimum resistance fcm(t ) at t time must be 50% of concrete resistance required for the complete pre-stressing phase. Between the minimum concrete resistance and the resistance required for the complete pre-stressing phase, there can be a value from 30% to 100% of complete pre-stressing force.


2.6 – Charateristics of strand

Strand

Diameter Standard Strand type Nominal diameter

Nominal section

fptk fp(1)k Massa tension

1% of elong..

Carico di rottura (Ptk)

Elastic limit

allo 0,1% Pt0,1k )

Rilassamento dopo 1000 h 0,7 - 0,8 fpt

mm mm2 N/mm2 N/mm2 gr/m KN KN KN % %

T15 T15S

EN 10138 normal super

15.2 15.7

139 150

1860 1860

1670 1670

1086 1172

232 250

259 279

228 246

2.5 2.5

4.5 4.5

T15C

EN 10138

T15C 15.2 165 1860 1670 1289 276 307 270 2.5 4.5

Modulo d’elasticità = 196 +/- 10 KN / mm2

Unbonded and greased strand

Diameter

Standard Strand

type Nominal diameter

Greased nominal dimater

Grease mass

Mass HDPE

Mass Area

Breaking load Fm

Elastic limit at

0,1% Fp(0,1)

Relaxation after 1000 h. 0,7 – 0,8 Rm

mm mm g/m g/m g/m mm2 KN KN % %

T15 T15S

EN 10138

normal super

15.2 15.7

18.00 18.50

40 40

75 78

1210

1290

139 150

259 279

228 246

2.5 2.5

4.5 4.5

T15C

EN 10138

T15C

15.2

18.00

35

70

1400

165

307

270

2.5

4.5

Elasticity modulus = 196 +/- 10 KN / mm2


3 – DETAIL DESIGN ASPECTS

3.1 – Arrangement of tendons

Post-tensioned floors can be thinner far a given loading and deflection limitation than reinforced concrete floors. This is primarily because of the load-balancing effect of the draped tendons. In the span, the deviation forces caused by the curved tendons act on the concrete to oppose gravity.

Transverse components and panel forces resulting from post-tensioning

Principle of the load-balancing method Where the tendon curvature is inverted, i.e. over the grid lines between the columns, the deviation forces act downward, inserting concentrated loads on the "column strip" tendons, i.e. the tendons running along the grid lines. These concentrated forces are balanced by the upward acting deviation forces from the column strip tendons which in turn insert a downward acting force on the columns. Thus the system shown in the figure can be compared to a net strung between the columns. When this net is stretched from all four edges it inserts the load-balancing forces on the concrete. The amount of post-tensioning steel can be determined by the condition that the draped tendons provide sufficient distributed deviation force to load-balance a certain percentage of the floor self weight. This percentage depends on the ratio of total load to permanent load and is typically between 70 and 130 %. For typical office or residential floors with live loads of 3 to 4 kN/m2 and 1 kN/m2 additional permanent load one would normally balance 70 to 90 % of the self weight while for floors with higher live loads more than 100 % of the self weight would be load-balanced


The other effect responsible for the improved deflection and cracking behaviour of post-tensioned floors is the in-plane compression stress field in the concrete stemming from the anchorages of the post-tensioning tendons. Provided that there are no significant restraints, these compression stresses neutralise a part of the flexural tensile stresses caused by the portion of the loading not balanced by deviation forces from the tendon drape. Typically the post-tensioning in floors provides an average in-plane compression stress of 1.0 to 2.5 N/mm2.

Now let us look at typical span-to-depth ratios of post-tensioned floors. For light loading, say up to about 3.5 kN/m2 and provided that punching shear is not critical, a post-tensioned flat plate can be designed with a thickness of about 1/40 of the larger span dimension (for interior panels), compared to about 1/30 for a flat plate in reinforced concrete. If drop panels are provided over the columns the span-depth ratio can be increased to about 45 and 35 for interior panels of post-tensioned and reinforced concrete slabs, respectively. For higher superimposed loading the span/depth ratio decreases, particularly if the super-imposed load is predominantly variable in place and time. Then the amount of post-tensioning cannot simply be increased to load-balance the super-imposed load so that in order to meet the deflection limitations a greater floor thickness is required.


3.2 - Joints

The use of post-tensioned concrete and, in particular, of concrete with unbonded tendons necessitates a rethinking of some long accepted design principles. A question that very often arises in building design is the arrangement of joints in the slabs, in the walls and between slabs and walls.

Unfortunately, no general answer can be given to this question since there are certain factors in favour of a certain factors against joints. Two aspects have to be considered:

-Ultimate limit state (safety) -Horizontal displacements (serviceability limit state)

3.2.1 - Influence upon the ultimate limit state behaviour If the failure behaviour alone is considered, it is generally better not to provide any joints. Every joint is a cut through a load-bearing element and reduces the ultimate load strength of the structure. For a slab with unbonded post-tensioning, the membrane action is favourably influenced by a monolithic construction. This results in a considerable increase in the ultimate load


Influence of membrane action upon load-bearing capacity

3.2.2 - Influence upon the serviceability limit state

In long buildings without joints, inadmissible cracks in the load-bearing structure and damage to non load-bearing constructional elements can occur as a result of horizontal displacements. These displacements result from the following influences:

-Shrinkage -Temperature -Elastic shortening due to post-tensioning -Creep due to post-tensioning In a concrete structure, the following average shortenings and elongations can be expected: Shrinkage ∆Lcs = -0.25 mm/m Temperature ∆Lct = -0.25 mm/m to +0.15 mm/m

Elastic shortening (for an average centric post-tensioning of 1.5 N/mm2 and Ec= 30 kN/mm2) ∆Lcel = -0.05 mm/m Creep ∆Lcc = -0.15 mm/m

These values should be adjusted for the particular local conditions.

When the possible joint free length of a structure is being assessed, the admissible total displacements of the slabs and walls or columns and the admissible relative displacements between slabs and walls or columns should be taken into account. Attention should, of course, also be paid to the foundation conditions. The horizontal displacements can be partly reduced or prevented during the construction stage by suitable constructional measures (such as temporary gaps etc.) without damage occurring.


Shrinkage: Concrete always shrinks, the degree of shrinkage being highly dependent upon the water-cement ratio in the concrete, the cross- sectional dimensions, the type of curing and the atmospheric humidity. Shortening due to shrinkage can be reduced by up to about one-half by means of temporary shrinkage joints.

Temperature: In temperature effects, it is the temperature difference between the individual structural components and the differing coefficients of thermal expansion of the materials that are of greatest importance. In closed buildings, slabs and walls in the internal rooms are subject to low temperature fluctuations. External walls and unprotected roof slabs undergo large temperature fluctuations. In open buildings, the relative temperature difference is small. Particular considerations arise for the connection to the foundation and where different types of construction materials are used.

Layout of the joint in WTC project

Elastic shortening and creep due to post-tensioning: Elastic shortening is relatively small. By subdividing the slab into separate concreting stages, which are separately post-tensioned, the shortening of the complete slab is reduced. Creep, on the other hand, acts upon the entire length of the slab. A certain reduction occurs due to transfer of the post-tensioning to the longitudinal walls. Shortening due to post-tensioning should be kept within limits particularly by the centric post-tensioning not being made too high. It is recommended that an average centric post-tensioning of σcpm = 1.5 N/mm2 should be selected and the value of 2.5 N/mm2 should not be exceeded. In concrete walls, the relative shortening between slabs and walls can be reduced by approximately uniform post-tensioning in the slabs and walls.


4. CONSTRUCTION PROCEDURES

4.1. General

The construction of a post-tensioned slab is broadly similar to that far an ordinarily reinforced slab. Differences arise in the placing of the reinforcement, the stressing of the tendons and in respect of the rate of construction. The placing work consists of three phases: first, the bottom ordinary reinforcement of the slab and the edge reinforcement are placed. The ducts or tendons must then be positioned, fitted with supports and fixed in place. This is followed by the placing of the top ordinary reinforcement. The stressing of the tendons and, in the case of bonded tendons the grouting also, represent additional construction operations as compared with a normally reinforced slab. Since, however, these operations are usually carried out by the post-tensioning firm, the main contractor can continue his work without interruption. A feature of great importance is the short stripping times that can be achieved with post-tensioned slabs. The minimum period between concreting and stripping of formwork is 48 to 72 hours, depending upon concrete quality and ambient temperature. When the required concrete strength is reached, the full (or partially) post-tensioning force can usually be applied and the formwork stripped immediately afterwards. Depending upon the total size, the construction of the slabs is carried out in a number of sections. The divisions are a question of the geometry of the structure, the dimensions, the planning, the construction procedure, the utilization of formwork material etc. The construction joints that do occur, are subsequently subjected to permanent compression by the post-tensioning, so that the behaviour of the entire slab finally is the same throughout. The weight of a newly concreted slab must be transmitted through the formwork to slabs beneath it. Since this weight is usually less than that of a corresponding reinforced concrete slab, the cost of the supporting structure is also less.


4.2. Fabrication of the tendons

4.2.1. Bonded post-tensioning

There are two possible methods of fabricating cables:

-Fabrication at the works of the post-tensioning firm

-Fabrication by the post-tensioning firm on the site

The method chosen will depend upon the local conditions. At works, the strands are cut to the desired length, placed in the duct and, if appropriate, equipped with dead-end anchorages. The finished cables are then coiled up and transported to the site. In fabrication on the site, the cables can either be fabricated in exactly the same manner as at works, or they can be assembled by pushing through. In the latter method, the ducts are initially placed empty and the strands are pushed through them subsequently. If the cables have stressing anchorages at both ends, this operation can even be carried out after concreting (except for the cables with flat ducts).


Slab using flat sheath; example of bonded post-tensioning. Strands are displayed, before casting, respecting the following phases:

- sheath display, - anchorage display, - vent display, - introduction of proper cut strand

into the sheath, - strand stressing, - grouting. Bonded post-tensioning applications with flat sheath, for multi strand installation, can be executed with:

- Anchorage series “L”, - Anchorage series “N”


4.2.1.1. Bonded post-tensioning anchoring

Bonded post tensioning is used for grouted and sheathed strands. The sheath can be made of HDPE or Steel. Sheath equipped with accessories (vent device and grouting) which guarantee proper adherence of the strand into the sheath itself.

1E15 bonded anchorage sheath diam. 25 mm.

1E15 bonded anchorage sheath diam. 40 mm.

1EX15 bonded anchorage sheath diam. 40 mm.

TTM mono strand anchorage has a bonded version, “E”, connected with corrugated sheath. Anchorages can be active and passive. In the passive version the anchor head is pre locked by using proper equipment. Pre locking forbids the wedge drown in, if cemented, guaranteeing long lasting lockage. HDPE sheath are supplied as 200 meters rolls equipped with accessories for mould jointing, venting and grouting. 1E15 anchorage is the standard version of anchorage for mono strand. All anchorages have forming mould jointing holes. 1E15 anchorages are made of steel C40-C45 EN 10083/1.

1E15 anchorage without wedge

Anchorages series 4-5L15 are equipped with flat sheath. The sheath allows grouting after stressing. Flat sheath can be galvanized.


5L15 bonded anchorage

4N15 bonded anchorage

The anchorage is completely protected by a surface of HDPE which prevents the corrosion. The anchorage has two versions: 4 or 5 strands T15.

Anchorages series 4N15 have flat corrugated sheath. The sheath allows grouting after stressing. Flat sheath can be galvanized Anchorage is made of casting iron EN-GJS 500-7 EN-JS-1050, The anchorage is supplied in the 4 strands version.


4.2.1.2. Mono strand anchorage series “E” ( Bonded post-tensioning )

The “E” series mono strand anchorage is produced in full compliance with the Italian regulations in force and according to the “FIP recommendations”. The “E” series mono strand anchorage comprises the following parts: casting, clamps and HDPE joint for connecting the casting to the strand coated with high density polyethylene.

Castings – All the castings have holes for connection to the forming mould and set up to receive the connection of a step which separates the anchorage from the mould. All the castings are made of spheroid iron EN-GJS 500-7 EN-JS-1050 (Italy: UNI ISO 4544 GS 500-7, France: NF A 32-201 FGS 500-7, Germany: DIN 1693 GGG50, U.K: BS 2789 500-7, ISO R 1083 50-7, Japan: J.S.I. G 5502 FCD 50), which offers high resistance to stress and, as it can be welded, guarantees increased safety during installation.

Wedges – Anchorage of the strand is achieved using 7015-T15 type 16NiCr4Pb UNI EN 10277-4 steel or 7017-T15 type 9SMnP28 UNI 4838 steel clamps. Joint – The connection between the anchorage and sheath is by means of a transition pipe that guarantees correct sealing of the anchorage.


GuarnizioneProlunga

Trefolo

Guaina corrugata

Iniezione / Sfiato

Spirale

Testata 1E15

Scassa

Baffo di tesatura

Prolunga

Trefolo

Guaina corrugata

Iniezione / Sfiato

Spirale

Testata 1E15


Cassaforma

GuarnizioneTestata 1E15

Trefolo

Prolunga

Spirale

Guaina corrugata

1E15 mono strand anchorage has two holes for mould jointing. .

The use of two screws guarantees the anchorage of the steel plate to the wooden mould.

We can supply spirals if required.

Slab ready for stressing with 1E15 anchorages.


Mono strand anchorage series “E”

A C

ØE

B

ØD

1E15

T T M

H

G

FØI

Type Last Charge A B C D E F

G H I T15 T15S T15C per cable per cable per cable ( KN ) ( KN ) ( KN ) (mm) (mm) (mm) (mm) (mm) (mm) (mm) (mm) (mm)

1EX15 259 279 300 59 40 130 110 6 130 85 155 35-40


4.2.1.Accessories for mono strand series “E and EX”

Short cap DD0115E

Half cap DD0115F

Long cap DD0115G

Washers in Neoprene type DD-7025

Protection cap for 1EX15 anchorages: - Cap type DD0115E for short strand

overhang, used for passive anchorages - Cap type DD0115F for half strand overhang

until 35 mm. - Cap type DD0115G for long strand overhang

until 70 mm. Short cap DD0115F is applied if the strand is cut near the wedge, for passive anchoring applications.

Long cap DD0115F is used on anchorages type 1EX15 where the strand is cut after moving the moulds.

DD-7025 type Neoprene washers for sealing against infiltrations.


Support for connecting to forming mould DD-7009-B

Support for mould jointing DD-7009-A

Joint DD-0115-CO in HDPE

Support for connecting to forming mould DD-7009-B without threaded pin for connecting to infill mould. The support can be re-used. .

Support for connecting to infill mould DD-7009-A with threaded pin for connecting to infill mould. The support can be re-used.

Connection DD-0115CO can be coupled to coated strand, guaranteeing no infiltration.

The rear joint is coupled to the casting by means of a push-fit device that guarantees sealing during the jet grouting phase.

R DD-0115-CO polythene joint for 1E15-B anchorages, can be assembled only on anchorages machined for connecting


Nut DD-9000

1E15 plate in steel

Nut for support for connecting to infill mould DD-9000 with threaded pin for fixing to infill mould.

“1EX15” anchorage can be entirely covered by HDPE, guaranteeing a perfect protection from corrosion.

Connection to infill mould – All heads are equipped with two equidistant holes so as to facilitate fixing to the infill mould by means of two bolts.

Accessories – All heads are equipped with accessories which complete the system.


4.2.1.4 Anchorage series “L” ( bonded post-tensioning )

Anchorage series “L” has been design for slabs or where the thickness of the strand cover requires flat sheath series “SL”.

Anchor plate – They are made of steel C40-C45 EN 10083/1 or spheroid casting steel EN-GJS 500-7 EN-JS-1050

Wedges – Fixing of strand is obtained by using wedges type 7015-T15 in steel 16NiCr4Pb UNI EN 10277-4 or type 7017-T15 in steel 9SMnP28 UNI 4838, Joint in H.D.P.E. - Il raccordo svolge una funzione di cassero ed alloggiamento per la piastra d’ancoraggio che è calcolata per trasferire lo sforzo direttamente sul calcestruzzo. Il raccordo è predisposto per la connessione con gli accessori, garantendo iniezione e sfiato.


Joints for grouting on anchorage type 4-5L15

4-5L15 anchorage is design in the two following versions:

- 4L15 version for compact strand T15, T15S and T15C,

- 5L15 version for strand T15, T15S and T15C,

Anchorages series “L” have two holes for grouting:

- frontal grouting joint, - back grouting joint.

Corrugated pipe for grouting and vent:

-DD 20x25 diam. 25 mm corrugated pipe for grouting and primary vents

-DD 15x20 diam. 20 mm corrugated pipe for grouting and secondary vents

Metallic sheath “ST” for anchorage type L

4-5L15 anchorage can be used with sheath SL


Metallic sheath introduced in the anchorage L

of different measures. The sheath is adapted on site by cutting the HDPE part at the corresponding section.



Anchorages series “L”

Type Last charge A B C D E F G H I L M T15 T15S T15C 259 279 300

per cable per cable per cable ( KN ) ( KN ) ( KN ) (mm) (mm) (mm) (mm) (mm) (mm) (mm) pz. (mm) (mm) (mm)

3L15 777 837 900 350 120 360 180 200 455 78x30 4 30 78 10 4L15 1036 1116 1200 350 120 360 180 200 455 78x30 4 30 78 12 5L15 1295 1395 1500 350 120 360 180 200 455 96x30 4 30 90 12


Anchorage 5L15


Anchorage 5L15 back side



4.2.1.5 Anchorage series “N” ( bonded post-tensioning )

Anchorage series “N” has been design for slabs or where the thickness of the strand cover requires flat sheath series “SL”.


Wedges – Fixing of strand is obtained by using wedges type 7015-T15 in steel 16NiCr4Pb UNI EN 10277-4 or type 7017-T15 in steel 9SMnP28 UNI 4838,


Joint for grouting on 4N15 anchorage

Anchorage 4N15 is used in the following version:

- 4N15 version for strand T15, T15S e T15C.


- frontal grouting joint, - back grouting joint

Corrugated pipe for grouting and vent:

-DD 20x25 diam. 25 mm corrugated pipe for grouting and primary vents

-DD 15x20 diam. 20 mm corrugated pipe for grouting and secondary vents

Metallic sheath “ST” for anchorage series N

4N15 anchorage can be used with sheath SL of different measures. The sheath is adapted on site by cutting the HDPE part at the corresponding section.


4.2.1.6 Anchorage series “M” ( bonded post-tensioning )

L’ancoraggio attivo serie “M” è composto dalle seguenti parti: fusione, piastra ancoraggio, morsetti e raccordo in H.D.P.E. per raccordare senza brusche deviazioni la fusione alla guaina metallica.

Anchorage- All anchorages have well rounded forming mould, jointing holes for cap and a ¾" grouting hole. Anchorages are made of spherical cast-iron EN-GJS 500-7 EN-JS-1050, which is highly resistant to solicitations. Anchorage are welding, this guarantees higher security during applications.

Anchor plate – Strand blocking is obtained through: a shearing out plate, with conical holes, which is made of steel C40-45 UNI EN 10083/1 ; wedges type 7015-T15 made of steel 16NiCr4Pb UNI EN 10277-4 or 7017-T15 in steel 9SMnP28 UNI 4838. Connection – Connection between sheath and anchorage is got through a transition pipe, which guarantees a proper strand deviation, decreasing losses. Connectors can be supplied in steel or in HDPE, in order to the applications. Connection to the mould – Anchorages have two equidistant holes, which facilitate the fixing by two nuts. Grouting – Anchorages have a ¾” threaded gas hole for grouting where can be jointed the outing accessories.


Rigid joint for grouting on anchorage 4M15

Corrugated joint for groutingon anchorage type 4M15

Anchorage 4M15 is used in the following version:

- - 4M15 version for strand T15, T15S e T15C,

Anchorages series “M” have two holes for grouting:

- frontal grouting joint, - back grouting joint

Metallic sheath “ST” for anchorages series M

4M15 4N15 anchorage can be used with sheath SL of different measures. The sheath is adapted on site by cutting the HDPE part at the corresponding section.


Anchorage series “M”

ØI

E

H

L C D

ØB

Ø F

A x

A G

A

A

Type Last charge A B C D E F G H I L T15 T15S T15C 259 279 300

per cable per cable per cable (KN) (KN) (KN) (mm) (mm) (mm) (mm) (mm) (mm) (mm) (mm) (mm) (mm)

4M15 1036 1116 1200 130 105 106 300 330 220 45/50 50 12 45 7M15 1813 1953 2100 160 125 133 340 390 260 62/67 55 12 45

The company has the faculty to change its products and its features without any forewarn. All anchorages are designed according to the Circular 15th October 1996 n° 252 AA.GG./S.T.C. and have a ministarial deposit.


4.2.2. Non bonded Post-tensioning The fabrication of mono strand tendons is usually carried out at the works of the post-tensioning firm but can, if required, also be carried out on site.

The mono strands are cut to length and, if necessary, fitted with the dead-end anchorages. They are then coiled up and transported to site. The stressing anchorages are fixed to the formwork. During placing, the mono strands are then threaded through the anchorages. Anchor head are fixed to the infill mould. During the phase of tendon display mono strands are put on the anchorages.


4.2.2.1 Mono strand anchorage series “E” ( Non bonded post-tensioning )

1E15 Anchorage

The “E” series mono strand anchorage is produced in full compliance with the Italian regulations in force and according to the “FIP recommendations”. The “E” series mono strand anchorage comprises the following parts: casting, clamps and HDPE joint for connecting the casting to the strand coated with high density polyethylene.

Anchorage – All anchorages have holes for casting jointing, so that they can be connected to a wooden mould which separates the anchorage from the form mould. Anchorage are made of C40-C45 EN 10083/1,

Wedges – Anchorage of the strand is achieved using 7015-T15 type 16NiCr4Pb UNI EN 10277-4 steel or 7017-T15 type 9SMnP28 UNI 4838 steel clamps. Joint – The connection between the anchorage and sheath is by means of a transition pipe that guarantees correct sealing of the anchorage.


TrefoloVipla

Spirale

Prolunga

Testata 1E15Baffo di tesatura

Guarnizione Scassa

Trefolo Vipla

Spirale

Prolunga

Testata 1E15


Cassaforma

GuarnizioneTestata 1E15

ViplaTrefolo

Prolunga

Spirale

Mono strand tendons with 1E15 anchorages pre locked at one edge, ready for being displayed.

1E15 anchorages after casting, ready for post-tensioning operations.


A C

ØD

ØE B

H

GF

Type Last charge A B C D E F G H T15 T15S T15C per cable per cable per cable ( KN ) ( KN ) ( KN ) (mm) (mm) (mm) (mm) (mm) (mm) (mm) (mm)

1E15 259 279 300 43 40 130 110 6 114 76 148


4.2.2.2. Accessories for non bonded post-tensioning

Bonded Post-tensioning uses strands which are protected from cement by grease and duct.

1E15 Anchorage

1EX15 Anchorage

1LX15 Anchorage

Mono strand anchorage has two versions: “E” and “EX”. Both anchorages are usable as passive and active head. In the passive version the anchor head is pre locked by using proper equipment. Pre locking forbids the wedge drown in, if cemented, guaranteeing long lasting lockage. 1E15 anchorage is the standard version of anchorage for mono strand. All anchorages have forming mould jointing holes. 1E15 anchorages are made of steel C40-C45 EN 10083/. All mono strand anchorages have two holes for mould jointing. .

The use of two screws guarantees the anchorage of the steel plate to the wooden mould.

Mono strand anchorage has in the back side a HDPE joint which forbids infiltrations during casting phase. In the 1EX15 version the anchorage is completely encapsulated by a HDPE cover which protects the anchorage from corrosion. Caps contain the grease which protects the wedge. . There is also 4L15 version: an anchorage which allows the anchoring of 4 -5 bonded strands. The strand will be stressed by mono strand hydraulic jack.


1EX15 passive anchorage

1EX15 passive anchorage

1EX15 active anchorage

Short cap for passive anchorage contains the grease protecting the wedge. Short cap is used for passive anchorages Half cap for passive anchorage contains the grease protecting the wedge before tampon. Long cap for active anchorage contains the grease protecting the wedge before tampon.


1EX15 Anchorage

1E15 Anchorage

1E15 anchorage jointed to the wooden mould

All anchorages “E” and “EX” can be jointed to the form work by two screws.

The wooden mould, if correctly used, is reusable.


4.2.2.3. Mono strand anchorage series “EX”

(Encapsulated non bonded post-tensioning )

The “EX” series mono strand anchorage is produced in full compliance with the Italian regulations in force and according to the “FIP recommendations”. The “EX” series mono strand anchorage comprises the following parts: casting, clamps and HDPE joint for connecting the casting to the strand coated with high density polyethylene.

Anchor plate– All anchor plates have holes for connection to the forming mould and set up to receive the connection of a step which separates the anchorage from the mould. All the castings are made of spheroid iron EN-GJS 500-7 EN-JS-1050 (Italy: UNI ISO 4544 GS 500-7, France: NF A 32-201 FGS 500-7, Germany: DIN 1693 GGG50, U.K: BS 2789 500-7, ISO R 1083 50-7, Japan: J.S.I. G 5502 FCD 50), which offers high resistance to stress and, as it can be welded, guarantees increased safety during installation.

Wedges – Anchorage of the strand is achieved using 7015-T15 type 16NiCr4Pb UNI EN 10277-4 steel or 7017-T15 type 9SMnP28 UNI 4838 steel clamps.

Joint – The connection between the anchorage and sheath is by means of a transition pipe that guarantees correct sealing of the anchorage.


Testata 1EX15

TrefoloVipla

Spirale

Prolunga

Baffo di tesatura

Scassa

Morsetto

Testata 1EX15

TrefoloVipla

Spirale

Prolunga

Tappo di chiusura


Cassaforma

GuarnizioneTestata 1EX15

ViplaTrefolo

Prolunga

Spirale


Bonded strand after the forme mould removing. The bound is displayed on the strands for temporary oxidation protection.


Cut tendons with pre locked passive anchorage. Tendons are uncoiled in a 2,2 meters rolls and have identification label.

Mono strand anchorage series “EX” (Encapsulated non bonded post-tensioning )


A C

ØD

ØE B

H

G

F

Type Last charge A B C D E F G H T15 T15S T15C per cable per cable per cable ( KN ) ( KN ) ( KN ) (mm) (mm) (mm) (mm) (mm) (mm) (mm) (mm)

1EX15 259 279 300 59 40 130 110 6 130 85 155


4.2.2.4. Anchorage series “L” ( non bonded post-tensioning )

Anchorage series “L” has been design for slabs or where the thickness of the strand cover requires flat sheath series “SL”.


Wedges – Fixing of strand is obtained by using wedges type 7015-T15 in steel 16NiCr4Pb UNI EN 10277-4 or type 7017-T15 in steel 9SMnP28 UNI 4838


Joint H.D.P.E. - Il raccordo svolge una funzione di cassero ed alloggiamento per la piastra d’ancoraggio che è calcolata per trasferire lo sforzo direttamente sul calcestruzzo. Il raccordo è predisposto per la connessione con gli accessori, garantendo iniezione e sfiato.

4-5L15 anchorage has two versions:

- 4L15 version used with compact strand T15, T15S and T15C,

- 5L15 version used with strands T15, T15S and T15C.


- frontal grouting joint, - back grouting joint.


Bonded and greased strands into the anchorage


Anchorage series “L” ( non bonded post-tensioning )


Type Last Charge A B C D E F G H I L M T15 T15S T15C 259 279 300

per cable per cable per cableo ( KN ) ( KN ) ( KN ) (mm) (mm) (mm) (mm) (mm) (mm) (mm) pz. (mm) (mm) (mm)

3L15 777 837 900 350 120 360 180 200 455 78x30 4 30 78 10 4L15 1036 1116 1200 350 120 360 180 200 455 78x30 4 30 78 12 5L15 1295 1395 1500 350 120 360 180 200 455 96x30 4 30 90 12

The company has the faculty to change its products and its features without any forewarn.


4.2.2.5. Anchorage series “M” ( non bonded post-tensioning anchorage )

Active Anchorage type “M” is composed by: anchorage, anchor plate, wedges and H.D.P.E. connector.

Anchorage- All anchorages have well rounded forming mould, jointing holes for cap and a ¾" grouting hole. Anchorages are made of spherical cast-iron EN-GJS 500-7 EN-JS-1050, which is highly resistant to solicitations. Anchorage are welding, this guarantees higher security during applications.

Anchor plate – Strand blocking is obtained through: a shearing out plate, with conical holes, which is made of steel C40-45 UNI EN 10083/1 ; wedges type 7015-T15 made of steel 16NiCr4Pb UNI EN 10277-4 or 7017-T15 in steel 9SMnP28 UNI 4838. Connection – Connection between sheath and anchorage is got trough a transition pipe, which guarantees a proper strand deviation, decreasing losses. Connectors can be supplied in steel or in HDPE, in order to the applications. Connection to the mould – Anchorages have two equidistant holes, which facilitate the fixing by two nuts. Grouting – Anchorages have a ¾” threaded gas hole for grouting where can be jointed the outing accessories.


Rigid grouting joint on anchorage M

Corrugated joint for grouting on 19M15 anchorage

- 19M15 anchorage is used with strand type: T15, T15S and T15C,

The rubber tampon confines the grouting into the anchorage, creating a recess which contains the protecting grease for strand and wedge.

“M” anchorages are made for the hereunder grouting:

- frontal grouting connector, - back grouting connector

Galvanized sheath type “ST” for M anchorages

M anchorage can be jointed to ST sheaths having different measures. Sheath can be adapted directly on site, by cutting the H.D.P.E. part according to the galvanized sheath section.


Anchorage series “M”

( non bonded post-tensioning )

ØI

E

H

L C D

ØB

Ø F

A x

A

GA

A

Type Last charge A B C D E F G H I L

T15 T15S T15C

259 279 300

per cable per cable per cable (kN) (kN) (kN) (mm) (mm) (mm) (mm) (mm) (mm) (mm) (mm) (mm) (mm)

4M15 1036 1116 1200 130 105 106 300 330 220 45/50 50 12 45 7M15 1813 1953 2100 160 125 133 340 390 260 62/67 55 12 45 9M15 2331 2511 2700 195 146 163 360 400 270 72/77 60 14 45 12M15 3108 3348 3600 225 160 185 385 430 320 80/85 65 14 45 15M15 3885 4185 4500 235 176 197 430 450 360 85/90 70 16 45 19M15 4921 5301 5700 265 200 215 430 500 400 95/100 75 16 56 22M15 5698 6138 6600 310 230 260 490 570 430 100/105 80 20 61 27M15 6993 7533 8100 330 250 277 500 650 470 110/115 90 20 70 31M15 8029 8649 9300 355 270 297 525 700 535 115/120 90 20 86 37M15 9583 10323 11100 375 280 314 590 730 560 130/135 90 20 86

The company has the faculty to change its products and its features without any forewarn. All anchorages are designed according to the Circular 15th October 1996 n° 252 AA.GG./S.T.C. and have a ministarial deposit.


Piastra ancoraggioFusione Tubo iniezione

Guaina corrugata

Raccordo


Cementing after positioning the vent and the HDPE conical reduction.

Insert of bonded strands into the anchorage. Cutting of HDPE protection in order to facilitate the removing after grouting.

Dispositivo ad espansione

Iniezione / Sfiato

Fixing of confining tampon, protecting the integrity of bonded and greased strands.


Grouting from corrugated pipes, remove of confining tampon.

Removing of pre marked bond, display of plates and docking wedges.

Display of wedges on the strands.


Pushing of wedges into the conical holes.

Martinetto

Anchorage stressing by “M” hydraulic jack, at the value indicated in the project.

Insert of grease into the hole of anchorage and filling of recess in the back side of anchor plate. This filling can also be executed before installing the anchor plate; however, the first solution is better as it is safer and it allows the complete eject of air.


Iniezione grasso

Grasso

700

Grouting is completed by positioning the cap filled with grease. The cap measure should contain the elongation of strand for future de-stressing.


5. EQUIPMENTS FOR STRESSING OPERATIONS

5.1 Hydraulic pump “TTM 450-A” ( mono strand anchorages stressing )

Hydraulic pump TTM450-A and TTM250-A

Six types of hydraulic pump are available for carrying out the stressing operations. This type of hydraulic pump is arranged with a two pipes, for operating TTM stressing jacks.

All the machines are provided with three control circuits: stressing, looking and return..

All the circuits are provided with regulation valves and safety valves for overpressure.

The control gauges are serially analogical, but they can be paired to a digital gauge with 1 bar precision.

The pushing machines type: 450, 550 and 600 were realised to be employed with mono-strand jacks and for simultaneous uses from 1 to 12 TTM250KN jacks.

All the machines are provided with a L=10 button strip, which allows to check all the operative phases of the machine. Suitable regulation valves allow the operator to change manually the pressure in the two circuits of the machine with high precision and ease.

Type Weight max. pressure Power Voltage/Ampere Use

( Kg. ) bar. KW

TTM450-A 170 450-500 4.5 380/16 TTM


5.2 Stressing Hydraulic Pump “TTM 650-E” ( Stressing of multi strand anchorages )

TTM 650-E hydraulic pump

This type of hydraulic pump is arranged with a two pipes, for operating TTM stressing jacks.

All the machines are provided with three control circuits: stressing, looking and return..

Type Weight Max pressure. Power Ampere use

( Kg. ) bar. KW

TTM 650-E 290 600 7 380/16 TTM


5.3 Manifold“DD-MF” ( stressing of mono strand anchorages by multi jacks)

All the machines give, by a manifold, the possibility to be connected with multiple stressing jacks. In order to do this they are provided with a manifold which allows the distribution of the pressure generated on multiple outlets.

Manifold DD-MF offers 4, 6 or 10 hydraulic exits in iso pressure, it is made of zinc iron and it is completely jointed.

manifold DD06MF

Manifold DD-MF can be connected to a manometer for pressure verifying during stressing activities. It can resist to 700 bar pressure. There are several type of manifold where the number indicate the number of exits for jacks connections:

- DD04-MF, - DD06-MF, - DD10-MF,

Different compositions are obtained jointing manifolds.

Type Weight Pressuremax. High from the

ground Dim. AxB

Number of exits

( Kg.) ( bar.) ( mm.) ( mm.)

DD 04-MF 20 450-500 40 500x500 4

DD 06-MF 28 450-500 40 900x500 6

DD 10-MF 35 450-500 40 1200x500 10


5.4 Hydraulic jack “TTM 250KN” ( mono strand anchorage stressing )

Hydraulic jack TTM 250KN

TTM jacks are available in three models. All the jacks are preset with an automatic wedging circuit and 4 meters flexible pipes

The principal use of this jack is in stressing TTR and E heads.

TTM250 KN jacks are provided together with the following equipment:

- TTM 450 KN hydraulic pump - DD-MF manifold

The main use of TTM250KN jacks are for tensioning on TTR heads or as single strand jacks on TTM anchorings.

TTM250KN jacks have the following strokes: 400 mm., 200 mm., 100 mm. and 60 mm.

Tipo Peso Corsa Diam. max. Lunghezza Presa Sezione Capacità

( Kg. ) ( mm. ) ( mm. ) ( mm. ) ( mm. ) ( cm2 ) ( KN )

TTM250KN 25 200 100 930 300 47,2 250


5.5 Hydraulic Jack type “TTM 280KN” ( mono strand anchorrings stressing )

Hydraulic jack type TTM280KN

There are three different models of Hydraulic jacks. All the jacks are preset with an automatic wedging circuit and 4 meters flexible pipes

TTM280KN jacks are used for mono strand anchorings stressing.

Type Weight Stroke Diam. max.

Dimensions Section Capacity

( Kg. ) ( mm. ) ( mm. ) ( mm. ) ( cm2 ) ( KN )

TTM280KN 28 200 100 270x500x220 51.3 250


5.6 Hydraulic jack type“TTM 300KN”

( Mono strand anchoring stressing )

Hydraulic jack TTM 300KN

There are three different models of Hydraulic jacks. All the jacks are preset with an automatic wedging circuit and 4 meters flexible pipes

TTM300KN hydraulic jack is mainly used for stressing on mono strand anchoring or even used as hydraulic jack on TTM anchorages.

Type Weight Stroke Diam. max. Lenght Section Capacity

( Kg. ) ( mm. ) ( mm. ) ( mm. ) ( cm2 ) ( KN )

TTM300KN 30 200 110 930 68.80 300


5.7 Wedging jack type “B300KN” ( Wedging jack for anchorages type 1E15 and 1EX15 )

Jack B300KN has been designed to enable mechanical wedging of clamp on series 1E15 anchorages and the use of the anchorage itself as passive anchoring completely buried in the concrete.

The principle of mechanically controlled wedging, is to eliminate drown-in of the clamps in the anchoring cones. The elimination of drown-in of the clamps is achieved using the B300KN jack which presses the clamp at such a thrust force that further loads applied after anchoring do not cause additional entry and the anchoring of the wire strand remains stable, guaranteeing the holding capacity of the passive anchoring.

Type Weight Push value Section Dimensions

( Kg. ) ( bar. ) ( cm2 ) ( mm. )

B300KN 60 450 54.75 760x260x200


5.8 Untwister jack type “S250KN” ( unwister jack for strand opening)

S 250KN Jack opens the strands and forms passive anchorages series S”.

In this type of anchoring, the wire strand, in correspondence with the passive end, is opened in order to improve adherence to the concrete Using many tendons, strands are displayed in alternative sense in order to equally distribute the fatigue on the concrete. .

The jack has been produced to open the wire strand at one end, allowing the strand itself, if correctly covered in the concrete, to have sufficient adherence to allow the anchorage of the tie-rod and thus eliminating the requirement for passive anchoring.

Type Weight Push value Hydraulic

pump Dimensions

Pressure at work

( Kg. ) ( bar. ) Tipo ( mm. ) ( bar. )

S 250 KN 30 250 TTM 700x300x250 180


5.9 Wrapping device “F2300-E” ( Device for wrapping of mono strand )

The wrapping device for cable wrapping is used for mono strand wrapping. Strand are cut and engraved on the HDPE protection. F2300-E device wraps the strands creating rolls of diameter 2,2 m, which are easily moveable on site.

Type Weight Max. Diameter Height Dimensions AxB max. load

( Kg. ) ( mm. ) ( mm. ) ( mm. ) ( Kg. )

F2300-E 250 2200 1250 1500x1500 160


5.10 Dynamometer “S 1000” ( Manometro digitale per verifica pressione )

The dynamometer “S 1000” is composed by master gauge S1000 and hydraulic transducer.

. Manometro campione S1000

The master gauge S1000 can carry out calibrations to compare the hydraulic system in use by means of connections upstream and downstream of the circuit.

It is supplied in a suitable insulated aluminium box inside which is enclosed a digital gauge with four digit read-out and 1 bar minimum read-out.

The read-out takes place by means of hydraulic insertion of a digital transducer with 1-1.000 bar. scansion which enables viewing of the pressure at the point of application.

The instrument can be supplied on request with different certifications:

- internal calibration, comparator gauge - official calibration through authorised laboratory

The master gauges are set for an operating pressure of 1.000 bar. They are supplied with CE markings, completely protected and equipped with identification serial number for periodical controls carried out by our technical service.

Type Weight Pression max. Power Dimensions Use

( Kg. ) bar. Volt. mm.

S1000 15 1.000 220 320x430x250 TTM


5.11 Grouting pump series “ T ” ( Pump for grouting of cables )

The “T” type grouting pump is designed to guarantee maximum versatility with regard to site requirements and use in severe conditions. It is supplied on wheels with robust tyres, it can be towed on-site and is equipped with all the safety devices necessary for use. The machine has two tanks: one for mixing the colloidal mix and one as a tank for the mix. The turbo mixer has a turbine capable of mixing material at 1500 rpm/min.

All the grouting pumps are fitted as standard with a gauge, gauge saving device and push-button pad with a 10 metre extension.

The “fast-on” fittings, litre-counters, plastic accessories, grouting tubes of various lengths, syringe and the Saunders flow closing valve are considered to be accessories

Pump T 500

Characteristics Model T500 ModelT400

Weight ( Kg. ) 900 900

Dimensions ( mm. ) 1900x1500x1900 mm 1900x1500x1900 mm

Mixing capacity ( litre) 190 litre 190 litre

Mixing time ( sec. ) 40” 40”

Shacking capacity ( litre ) 200 litre 200 litre

Max. grouting pressure ( bar. ) 10-20 bar. 10-20 bar.

Max. grouting capacity 25-40 litre/minut 15-25 litre/minut

Shaker power ( Kw ) 10 KW 10 KW

Potenza pompa ( Kw ) 7,5 KW 7,5 KW


5.12 Uncoiler type “ B1500 ”

The B1500 Uncoiler has been designed to make the threading operations of the strand into the sheaths easier.

It is usually used in combination with a strand pusher and guarantees unwinding of the strand without tangling at a high unwinding speed. It is set up to host coils of different dimensions and by connecting the two shoulders it can adapt to coils of different diameters.

The B1500 Uncoiler does not require special anchoring to the ground, its own weight is sufficient to guarantee its stability when being used.

The coil of strand is inserted between the two shoulders, before cutting the metal band straps, the correct tightening of the closing tie-rods, which guarantee correct blocking and safety of the operations, must be checked.

On cutting the band straps the unwinding direction shown on the coil must be complied with to guarantee the strand will unwind smoothly.

Type Weight max. capacity Weight with

load Dimensions

( Kg. ) ( mm. ) ( Kg. ) mm.

B1500 180 1.000 220 2500x2500


6. Sites




















Documents

TTM Slab Bonded and Unbonded Systems