Lockable Dowels for Temporary Movement Joints...Contents Advantages and Applications 2-3 Range of...

Lockable Dowels For Temporary Movement Joints

CI/SfB (29) Et6

September 2012

Contents

Advantages and Applications 2-3

Range of Lockable Dowels 4-5

Performance Data 6

Edge Distance and Spacings 7

Reinforcement Details 8

Dimensions 9

Installation 10

Projects 11

Other Ancon Products 11

Ancon Lockable Dowels

AdvantagesThe use of Lockable Dowels can save asignificant amount of time and materialsover other construction methods. Concreteshrinkage has traditionally beenaccommodated by leaving gaps in the slabcalled ‘pour strips’ or ‘closure strips’. Thesestrips are filled once movement has stabilised,however until they are filled the slabs must bepropped, restricting site access and delayingsite progress. Gaps in the slab also create atrip hazard for site workers, use additionalformwork and can leave the soffit face marked.

Lockable Dowels improve site access,minimise formwork requirements andaccelerate the rate of construction. With aLockable Dowel, there is less requirement forthe slabs to be propped or a support corbel tobe constructed, as shear load is transferred bythe dowel. The time saved by early removal ofslab props can be significant.

A Lockable Dowel also provides manyadvantages over the site-assembledarrangement of carbon steel reinforcing bar,galvanised or plastic ducting, vent tubes and anon-specific grout, which is sometimes usedby contractors.

In addition, engineers have found the AnconLockable Dowel to be the preferred designsolution for pin-ended joints. Although it iscustomary for practical reasons to use U-barsor other rebar continuity systems at theseconnections, these options do not truly act ashinges and so rotation of the slab under loadcan induce cracking at the wall-to-slabinterface with potential integrity issues.

The Lockable Dowel is closer to a true pin-ended joint and, being manufactured fromstainless steel, provides additional corrosionprotection over systems using carbon steelreinforcement.

The design capacities shown on page 6 arebacked by independent test data and theunique void former allows inspection of thedowel before the joint is locked.

Standard Ancon systems are available for useat slab joints and retaining / core walls.

Lockable DowelsLockable Dowels have been designed byAncon for use at temporary movement joints,most commonly found in post-tensionedconcrete frames.

These dowels allow initial shrinkage of theconcrete to take place and are then locked inposition with a mechanical plate and acontrolled amount of epoxy resin. The lockeddowels continue to transfer shear, but preventfurther movement taking place.

The performance of site assembledsystems can be unreliable

Pour Strips restrict site access, cause atrip hazard and delay progress on site

2 Tel: 1300 304 320 www.ancon.com.au

3

The consulting design engineer wanted a one metre widepour strip to be left open for 90 days which wasn’tacceptable to Hansen Yuncken. Using the Lockable Dowelsystem from Ancon allowed earlier formwork stripping andwork to continue with our services, thereby reducing overallconstruction time.Brent Courtney, Senior Site Manager, Hansen Yuncken

ApplicationsIn most cases, Ancon Lockable Dowels can be used to replace pourstrips at temporary movement joints in post-tensioned concrete frames.Standard Ancon systems are available for use at slab joints andretaining / core walls.

Slab-to-Slab

��

Additional formwork,trip hazard and

restricted access

Slabs proppedfor several weeks

Various site-assembled components

Unreliable performance, additional constructionmaterials used and support corbel or prop required

Proven performanceMinimal material usage

Minimal formworkImproved site access

Reduced propping time

Improved site accessReduced propping time

Ancon Lockable Dowel

Slab-to-Slab

�

�Pour strip in slab

Restricted access

Slabs proppedfor several weeks

Slab-to-Wall

�Pour strip at wall-to-slab junction



�



Slab-to-Slab Lockable DowelsESDQ-L20*The dowel component is manufactured from30mm diameter stainless steel; one end isthreaded with a fixed nut and washer, and theother features a series of grooves to acceptthe Locking Plate. The cylindrical sleeve whichaccepts the dowel component is containedwithin a box-section to allow lateral,longitudinal and some rotational movement.The epoxy resin is poured into the L-shapedvoid former. This product has a designcapacity of almost 70kN in shear and up to100kN in tension. See pages 6-9 for fulltechnical details.

HLDQ-L30*The HLDQ-L30 is a high load Lockable Dowelwith a design capacity of up to 136kN in shearand up to 100kN in tension. See pages 6-9 forfull technical details.

Range of Lockable DowelsA Lockable Dowel allows initial shrinkage of the concrete to take place and then, after apre-determined time period (generally 90-120 days), is locked in position with a mechanical plateand a controlled amount of epoxy resin. The range comprises three products; ESDQ-L20,HLDQ-L30 and ESDQ-L20W.

* Patent pending

Locking Plate(notches indicateminimum resin depth)

Two-part Epoxy Resin

Sleeve Component featuringvoid former supplied with labelon nailing plate

ESDQ-L20for Slab-to-Slab

HLDQ-L30for Slab-to-Slab

Dowel Component

Example Specification ClauseDelete/Amend blue text as appropriate

<Ancon ESDQ-L20 or Ancon HLDQ-L30> lockable shear load connector comprising dowel,sleeve and locking components to be installed at the temporary movement joint between twoslabs. Product to be positioned at <insert centres>mm horizontal centres at <the centre line ofthe slab or XXXmm from the top of the slab>. The dowel is to be locked in position after<insert time period> using the locking plate and resin supplied. System should be installed inaccordance with Ancon’s instructions and engineer’s drawings.




Dowel Component

HLDQ-L30 Sleeve nailed to formwork

Reinforcement around ESDQ-L20 Sleeves

5




ESDQ-L20Wfor Slab-to-Wall

Dowel Component

* Patent pending

SKS24 Threaded Anchorsupplied with a nailing plate

Slab-to-Wall Lockable DowelESDQ-L20W* The dowel component is manufactured from30mm diameter stainless steel, but is shorterthan the ESDQ-L20 dowel. One end of thedowel is designed to fix into the stainless steelAncon SKS24 Threaded Anchor cast into theface of the concrete and the other endfeatures a series of grooves to accept theLocking Plate. The sleeve component is thesame as used in the ESDQ-L20. See pages6-9 for full technical details.

Epoxy ResinEach dowel is locked after a pre-determinedtime period (generally 90-120 days) with a highquality, two-part epoxy resin. The resin ismixed and poured into the L-shaped voidformer. Each dowel requires 1,500g of resinwhich is supplied in a single can for eachdowel to control the quantity.

Slab-to-Wall Application

Example Specification ClauseDelete/Amend blue text as appropriate

Ancon ESDQ-L20W lockable shear loadconnector comprising dowel, sleeve,threaded anchor and locking componentsto be installed at the temporary movementjoint between slab and wall. Product to bepositioned at <insert centres>mmhorizontal centres at <the centre line of theslab or XXXmm from the top of the slab>.The dowel is to be locked in position after<insert time period> using the lockingplate and resin supplied. System should beinstalled in accordance with Ancon’sinstructions and engineer’s drawings.

Sleeve pushed over dowel component atcore wall

Void formers shown at Slab-to-Wall joint

5



Performance DataMovement

Vertical load transferbetween slabs

LockedVertical load transferbetween slabs

Load transferbetween slabs

ESDQ-L20 ExampleSlab thickness = 240mmJoint width = 20mmConcrete strength = 32MPaCharacteristic permanent action (dead load) = 45kN/m λG = 1.2Characteristic variable action (imposed load) = 50kN/m λQ = 1.5Design load = 1.2 x 45 + 1.5 x 50 = 129kN/m

Vertical design capacity = 62.2kN (240mm slab 20mm joint)

Therefore centres for vertical load = 62.2 / 129 = 0.482m use 450mm centres

Each dowel will in addition provide a design capacity across the joint of 100kN (for slab towall this is 80kN), therefore the total design capacity in the direction of the dowel = 100 /0.45 = 222kN (for slab to wall 80 / 0.45 = 177kN).

If this is insufficient, the dowel centres can be reduced to a minimum of 1.5 x slab thicknessto increase the design capacity across the joint, in this example it would increase to 100 /0.36 = 277kN (for slab to wall 80 / 0.36 = 222kN).

Slab Tension along Vertical Design Capacity (kN) at Various Design Joint Widths (mm)Thickness line of dowel in 32MPa Concrete(mm) (kN) 5 10 15 20 25 30 35 40

160 45 12.0 12.0 12.0 12.0 12.0 12.0 12.0 12.0

180 65 25.0 25.0 25.0 25.0 25.0 25.0 25.0 25.0

200 80 40.0 40.0 40.0 40.0 40.0 40.0 40.0 40.0

220 100 53.6 53.6 53.6 53.6 53.6 53.6 53.6 52.7

240 100 62.2 62.2 62.2 62.2 60.6 57.8 55.2 52.7

260 and above 100 71.4 69.9 66.6 63.5 60.6 57.8 55.2 52.7

ESDQ-L20 Lockable Dowels (slab-to-slab)


160 45 12.0 12.0 12.0 12.0 12.0 12.0 12.0 12.0

180 65 25.0 25.0 25.0 25.0 25.0 25.0 25.0 25.0

200 80 40.0 40.0 40.0 40.0 40.0 40.0 40.0 40.0

220 80 53.6 53.6 53.6 53.6 53.6 53.6 53.6 52.7

240 80 62.2 62.2 62.2 62.2 60.6 57.8 55.2 52.7

260 and above 80 71.4 69.9 66.6 63.5 60.6 57.8 55.2 52.7

ESDQ-L20W Lockable Dowels (slab-to-wall)


240 and above 100 136.0 136.0 136.0 136.0 136.0 136.0 136.0 121.9

HLDQ-L30 Lockable Dowels (slab-to-slab)

Movement +/-20.5mm

Locked

Joint Filler / Fire Protection

Ancon can provide information on a suitablejoint filler and also recommend fire resistantmaterial which could be used as part of anoverall fire protection system.

7

ESDQ-L20 Example

Slab thickness = 300mmJoint width = 20mmConcrete strength = 32MPaDesign capacity/connector = 63.5kN (based on slabs 260mm and above)Spacing for max. load 300 x 1.5 = 450mmEnd distance for max. load 450 x 0.5 = 225mmDesign capacity/metre = 63.5 / 0.45 = 141.1kN/m

As an ESDQ-L20 can be used in a 220mm slab for a design capacity per connector of up to 53.6kN, the spacing can be based on a 220mm slab. Therefore:

Reduced spacing 220 x 1.5 = 330mmReduced end distance 330 x 0.5 = 165mmDesign capacity/metre 53.6 / 0.33 = 162.4kN/m

240mmmin.

180 min. 360 min.

h

min. 0.75h min. 1.5h

Edge Distance and SpacingsFor connectors working at or near their maximum capacity, the minimumspacing should be 1.5 times the slab thickness. Where the design load of the connector could beused in a thinner slab, a spacing of 1.5 times the thinner slab thickness can be used. The minimumend distance is always 0.5 times the spacing.

ESDQ-L20 Minimum Edge Distance and Spacings

HLDQ-L30 Minimum Edge Distance and Spacings

ESDQ-L20W Minimum Edge Distance and Spacings. h = depth of adjoining slab

0.75h 1.5h


Reinforcement DetailsLocal reinforcement is required around each Ancon Lockable Dowel to guarantee that the forces are transferred between the connectors and theconcrete. Correct detailing in accordance with appropriate design codes and the recommendations provided here will ensure the dowels attain theirfull capacity. The tables show the main reinforcement required, together with details of reinforcement above and below the connectors. Although onlythe sleeve components are illustrated, the same reinforcement is required around the dowel component.

Threaded AnchorReinforcement around the Ancon Threaded Anchor should be a minimum diameter of12mm, installed at maximum 200mm vertical and horizontal centres.

Options for Main Reinforcement

Lockable Dowel No. of U-bars each sideRef. H12 H14 H16

ESDQ-L20 2 - -

HLDQ-L30 4 3 3

Options for Longitudinal Reinforcement

Lockable Dowel No. of bars top and bottomRef. H12 H14 H16

ESDQ-L20 2 - -

HLDQ-L30 2 2 2Main

reinforcementeach side

Main reinforcementeach side

Longitudinalreinforcement

above


below


above


below


above


below

Mainreinforcement

each side


above


below

ESDQ-L20

HLDQ-L30

SKS24 Threaded Anchor, part of ESDQ-L20W

HLDQ-L30

ESDQ-L20

Main reinforcementeach side


DimensionsESDQ-L20 ComponentsDowel Component Sleeve Component

HLDQ-L30 ComponentsDowel Component Sleeve Component

ESDQ-L20W ComponentsSKS24 Threaded Anchor Dowel Component

170mm

240mm110mm

450mm

31mm InternalDiameter

30mm

115mm161mm 12mm12mm

140mm 140mm

Max. +/-20.5mmlateral movement


30mm

270mm490mm 280mm

170mm

170mm

240mm

31mm internaldiameter

31mm internaldiameter

91mm

M30x3.5mm

40mm

150mm

100mm

110mm


100mm

Sleeve Component

30mm

270mm

103mm

HLDQ-L30 Sleeve Component

9



InstallationSlab-to-SlabAlthough installation is shown for the ESDQ-L20, the procedure is the same for the HLDQ-L30.

Slab-to-Wall

Notes: Where deep concrete pours are proposed, the installation will require further consideration. More robust fixing of the sleeve and dowelcomponents will be necessary, to avoid displacement during casting of the concrete.

Nail the sleeve to the formwork either central inthe slab or for slab depths over 300mm so thetop of the void former is level with the top of theslab. Do not remove the label over the nailingplate as this prevents ingress of concrete intothe sleeve. Fix the local reinforcement, asspecified on engineer’s drawings.

1 2

Pour the concrete, and when of sufficientstrength, strike the formwork. Puncture thelabel to reveal the cylindrical sleeve only andinsert the dowel until it is approximately 20mmfrom the back of the void former.

Mix the two-part epoxy resin and pour into thevoid former. It is essential the resin flows alongthe stainless steel box section towards thejoint and reaches the notches on the lockingplate, which indicate minimum resin depth.

Joint must be filled before resin is installed.

After a predetermined time period (generally90-120 days), when movement between theslabs has stabilised and the joint between theslabs has been filled, the dowel is ready to belocked.

Fit the Locking Plate on a groove in the centreof the void former. The fan-shaped LockingPlate allows the dowel to be locked in anyposition.

5

After 24 hours the void former can be filledwith cementitious material, level with the top ofthe slab, to complete the installation.

The locked dowel continues to transfer verticalload between the slabs, but movement can nolonger take place.

64

Fix the local reinforcement around the dowelcomponent and pour the concrete.

3

Nail the threaded anchor to the formwork sothe dowel will be central in the adjoining slabor within 150mm of the top of slabs over300mm. Fix the local reinforcement asspecified on engineer’s drawings and cast theconcrete.

1 2

When concrete reaches sufficient strength,strike the formwork and remove nailing plate.Screw the dowel into the anchor.

Puncture the label of the sleeve to reveal thecylindrical sleeve only. Push the sleeve over thedowel until it is flush with the concrete. Tiesleeve to reinforcement and pour concrete.

See Steps 4 to 6 above to completeinstallation.

3

11

Project References Other Ancon Products

DSD/Q Shear Load ConnectorsAncon DSD and DSDQ double-dowelconnectors are used to transfer shear acrossmovement joints in suspended concrete slabs.They are more effective at transferring loadand allowing movement than standard singledowels and can be used to eliminate doublecolumns at structural movement joints inbuildings. The Q version features a rectangularbox section to allow lateral and some rotationalmovement.

Plate Dowel SystemsAncon MultiJoint is a plate dowel system foruse in ground bearing concrete floor slabs. It isan all-in-one solution to load transfer, concretecontraction, armoured edge protection andformwork. Individual plate dowels are alsoavailable.

Punching Shear ReinforcementAncon Shearfix is used within a slab to provideadditional reinforcement from punching sheararound columns. The system consists ofdouble-headed steel studs welded to flat railsand is designed to suit the load conditions andslab depth at each column using freecalculation software from Ancon.

Reinforcing Bar CouplersThe use of reinforcing bar couplers canprovide significant advantages over lappedjoints. Design and construction of the concretecan be simplified and the amount ofreinforcement can be reduced. The Anconrange includes BT parallel-threaded and MBTmechanically-bolted couplers.

Reinforcement Continuity SystemsReinforcement Continuity Systems are anincreasingly popular means of maintainingcontinuity of reinforcement at construction jointsin concrete. The Ancon Keybox systemeliminates the need to drill shuttering and cansimplify formwork design, thereby acceleratingthe construction process. It is available in bothstandard units and special configurations.Ancon KSN Anchors eliminate the need for o n-site bar straightening and are available asstandard to accept 12mm, 16mm and 20mmdiameter rebar. The system is also available witha re-useable rebate former.

Stainless Steel ReinforcementAncon supplies stainless steel plain and ribbedbar in a variety of grades, including high proofstrength material, direct from stock. Bardiameters range from 6mm to 50mm and canbe cut to length, bent and threaded to suit anyapplication. Stainless steel BT couplers arealso available to suit bars from 12mmdiameter.

5,000 Lockable dowels were installed onthe Royal Children’s Hospital, Melbourne,VIC

2,500 Lockable dowels were installed onthe Supreme & District Court, Brisbane,QLD

500 Lockable dowels were installed on theEmergency Care Centre in Aberdeen, UK

© Ancon Building Products 2012

The construction applications and details provided in this literatureare indicative only. In every case, project working details should beentrusted to appropriately qualified and experienced persons.

Whilst every care has been exercised in the preparation of thisdocument to ensure that any advice, recommendations orinformation is accurate, no liability or responsibility of any kind isaccepted in respect of Ancon Building Products.

With a policy of continuous product development Ancon BuildingProducts reserves the right to modify product design andspecification without due notice.

These products are available from:

Ancon Building Products7-9 Second AvenueSunshineMelbourneVIC 3020AustraliaTel: 1300 304 320Fax: +61 (0) 3 9311 1777

Ancon Building Products82 Chisholm CrescentKewdalePerthWA 6105AustraliaTel: 1300 304 320Fax: +61 (0) 8 9453 2300

Ancon Building Products114 Kurrajong AvenueMount DruittSydneyNSW 2770AustraliaTel: 1300 304 320Fax: +61 (0) 2 9675 3390

Ancon Building Products4/15 Terrace PlaceMurarrieBrisbaneQLD 4172AustraliaTel: 1300 304 320Fax: +61 (0) 7 3395 6693

International Enquiries: +61 (0) 2 8808 1111Email: [email protected]: www.ancon.com.au

Overseas Offices:

Ancon Building ProductsSheffieldUnited Kingdomwww.ancon.co.uk

Ancon Building Products GesmbHViennaAustriawww.ancon.at

Ancon (Schweiz) AGRied bei KerzersSwitzerlandwww.ancon.ch

Ancon GmbHNurembergGermanywww.anconbp.de

Ancon (Middle East) FZEDubaiUnited Arab Emirateswww.ancon.ae

Masonry Support Systems

Windposts and Lintels

Wall Ties and Restraint Fixings

Channel and Bolt Fixings

Tension and Compression Systems

Stainless Steel Fabrications

Flooring and Formed Sections

Shear Load Connectors

Stainless Steel Reinforcement

Reinforcing Bar Couplers

Reinforcement Continuity Systems

Punching Shear Reinforcement

Precast Concrete Accessories

Lockable Dowels for Temporary Movement Joints...Contents Advantages and Applications 2-3 Range of...

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