grace strux beton.pdf

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3Effectiveness and use ofsynthetic fibres in Concrete

Gerard AttreeEngineering Services Group

Engineering Services Group EMEAI

Tuesday, 17 December2013


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2012 W. R. Grace & Co. Engineering Services Group EMEAI

History of fibres

What is STRUX?

Why STRUX?

Fibres in concrete

Performance Testing

Market Segments

Advantages with STRUX

STRUX CE Marking & Approvals

Major Projects

Replacing steel fabric with fibre reinforcement

Questions


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2012 W. R. Grace & Co.

History of fibres


The use of natural fibres to strengthen brittle

materials goes back to ancient times:

3500 years ago: sun baked bricks were

reinforced with straw

In the 1950s & 1960s, steel and glass fibres

were used for concrete

Today: hundreds of different fibers are

available for use in concrete to solve different

problems

But why do we need fibres in concrete?


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Why do we need fibres in concrete?

Concrete is a very brittle material


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Problem concrete?

Problem concretes CRACK!


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Where do we see cracks in concrete?


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Fibres in concrete the options

The addition of fibres to concrete can significantly affect either the plastic and / or hardened

properties of concrete mixes

The choice of fibre to use should be made based on what properties are required from theconcrete, for example,

Reduced bleeding

Flexural toughness

Enhanced impact resistance

Freeze / thaw resistance

Adding fibres to the wrong concrete mix is not the answer!

Add fibres to a concrete mix which has been designed to accommodate fibres!


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Fibre Types

Polypropylene Micro fibres

Synthetic Macro fibres

Steel fibres


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Reinforcement Options

Micro

Fibres

Steel Fabric Steel

Fibres

STRUX

90/40

Safe, Easy

Handling

Plastic Shrinkage

Crack Control

Drying Shrinkage

Crack Control

Post Crack Load

Carrying Capacity

Freeze-Thaw

Protection

Non-Corroding

P

lastic

C

oncrete

Hardene

d

Concrete


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What is STRUX 90/40

Unique patented designExcellent crack control

Excellent flexural toughness

Property Value

Specific Gravity 0.92

Tensi le Strength 620 MPa

Modulus of

Elasticity

9.5 GPa

Aspect Ratio 90

Chemical

Resistance

Excellent

Absorpt ion None


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What is STRUX 90/40

Unique patented designExcellent crack control

Excellent flexural toughness

Property Value

Specific Gravity 0.92

Tensi le Strength 620 MPa

Modulus of

Elasticity

9.5 GPa

Aspect Ratio 90

Chemical

Resistance

Excellent

Absorpt ion None

These physical properties clearly differentiates

STRUX 90/40 from its competitors other

synthetic macro fibres are much weaker in

tension (e.g. 250 MPa) than STRUX 90/40US Patent Nos: 6.569.525; 6.569.526; 6.863.969

EP 1.253.223


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Benefits of STRUX in concrete

STRUX has been designed to

provide:Safety

Ductility

Durabili ty

Crack control

Impact resistance

Stain free concrete surfaces

Quick, easy and safe application

Efficient and cost effective

reinforcement optionSustainable


Three dimensional reinforcement system


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Why STRUX 90/40?

STRUX fibres are completely

dispersed throughout the concrete.

Their high surface area gives themexcellent bond to the concrete matrix.This coupled with their high strengthmakes them very difficult to break or

pull out.

They work by intersecting cracks asthey begin to form. In this way,STRUX fibres provide concrete with a

residual load carrying capacity, evenafter the concrete has cracked


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Testing of Synthetic Fibre Reinforced Concrete


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Flexural stress vs. deflection

Grade C40 (54 N/mm2 @ 28 days) with STRUX 90/40 @ 4.6kg/m3

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5

5.5

6

6.5

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 2.2 2.4 2.6 2.8 3

Deflection (mm)

FlexuralStress(M

Pa)

Beam 1

Beam 2

Beam 3

Beam 4

Peak Flexural Strengths

Beam 1; 5.09 MPa

Beam 2; 5.72 MPa

Beam 3; 5.53 MPa

Beam 4; 6.10 Mpa

Mean; 5.61 MPa

Residual Flexural Strengths

Beam 1; 2.79 MPa

Beam 2; 2.70 MPa

Beam 3; 2.52 MPa

Beam 4; 2.75 MPa

Mean; 2.69 MPa

Re3Values

Beam 1; 54.9 %

Beam 2; 47.1 %

Beam 3; 45.5 %

Beam 4; 45.1 %

Mean; 48.2 %


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How does STRUX 90/40 work?


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Where STRUX can be usedA wide range of internal s labs replacing fabric and light rebar

http://../Rimini%20Marzo%202004/Ice%20Stadium%20Fanano%20Oct%202003.pdf


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Where STRUX can be usedA wide range of external slabs replacing fabric and light rebar



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Where STRUX can be usedA wide range of precast applications replacing fabric and light rebar

Steps Parking

kerbs

Septictanks

Manholes

Pipes

Insulated wall

panels


Sea Defence

Segmental Linings


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Where STRUX can be usedComposite metal decking applications replacing fabric



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Advantages of STRUX 90/40

Speed of use Reinforcement is delivered and poured with the concrete.

STRUX 90/40 is distributed uniformly throughout the concrete.

Health & Safety No exposed steel or onsite storage.

High fibre content at low dosage weight.

Exposed fibres Surface, STRUX 90/40 fibres pose no corrosion or durability problems.

Improved flexural toughness Especially in elements of 4 (100 mm) and more.

Enhanced impact resistance.

Plastic shrinkage control. No need for additional plastic shrinkage fibres.

Low environmental impact Viable option for production of low carbon concrete.

STRUX macro-fibres can achieve the same performance as steelfabric with several benefits



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Tradit ional Reinforcement ChallengesTraditional industry practice uses steel fabric for crack control

Challenges of using steel fabric

Difficult to pour and consolidateconcrete with steel fabric.

Represents an additional step inthe construction; placing requiresHealth & Safety considerations.

Effectiveness of crack controldepends on position of the fabric.

Corrosion and Durability problemsassociated with cracking and meshposition

Hauling & stocking is not always

easy and can be expensive.



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CE marking, EN14889-2

CPD

ConstructionProductsDirective

CPR

ConstructionProducts

Regulations

July 1st2013

CE marking

required for

legal saleVoluntary

Declaration of ProductPerformance based on: Harmonised technical

specification Agreed system of conformity

assessment Framework of Notified Bodies CE Marking of products

CE Marking indicates a product isconsistent with its Declaration ofPerformance In the case of macro-synthetic fibres like

STRUX a declared value according to EN14889-2 is used

The declared values include tensile strength

and elastic modulus and a dosage toachieve a standard performance

Performance equals dosage efficiency There are further requirements within the

test that must be observed Constant, single length fibres Fibre must be tested as sold

Polymer fibres for concrete

Polymer type: Polypropylene/Polyethylene

Class II

Length: 40mm

Equivalent Diameter: 0.433 mm

Shape: cross sectional area rectangular

Tensile strength: 620N/mm2

Elastic modulus: 9500 N/mm2

Effect on consistence with 3.5kg/m3fibres:

Vebe time: 10s (Reference concrete 7s)

Effect on strength of concrete:

3.5kg/m3to obtain 1.5N/mm2at CMOD=0.5mm

and 1 N/mm2 at CMOD=3.5mm

UK

Hightensile

strengthindicates astronger

fibre

Indicatesresidual

(post-crackflexural

strength)performance



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BS EN 14889-2

Confidence in Quality, Performance and Pedigree


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External approvals


Confidence in Quality, Performance and Pedigree


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Khalifa Port and Industr ial Zone ProjectSTRUX Project Profile

Product: STRUX 90/40

Project Name: Khalifa Port andIndustrial Zone Project ContainerTerminal

Location: Taweelah Abu Dhabi

Total Project value: $390 Million

Total Project Area: 1,000,000m2

Project Start and finish: Mar 2011 Feb 2012

100 year service life guaranteerequired for slab in high chlorideconditions required both highdurability concrete and a non

corroding reinforcement nopractical alternative to macrosynthetic fibers.

STRUX chosen due to previouspedigree and specifier familiarity.



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The Georgia Aquarium, Atlanta, USASTRUX Project Profile


Designed to look like a modernNoahs Ark, the new Georgia

Aquarium in downtown Atlanta

destined to be the largestaquarium in the world and one ofthe major tourist attractions in thestate.

Given the challenging nature of theproject a team from GraceConstruction Products had to meetthe complex demands of this

construction. The tanks are amongthe largest in the world.

STRUX 90/40 was used forsecondary reinforcement in slabon- ground concrete throughoutthe structure, including concretewalkways, areas near the tanksand other high traffic locations.

STRUX is safer to use, reducesthe potential for damage towaterproofing materials placedunder the concrete and eliminatesthe risk for corrosion compared toother types of reinforcement.



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New Sea Defence, Blackpool, UKSTRUX Project Profile


76m scheme to future proof thenorth wests leading holiday resortagainst flooding.

Blackpool Central Area CoastProtection Scheme employedinnovative design and constructiontechniques to deliver a flagshipscheme combining vital coastalprotection improvements alongwith an enhanced seafrontenvironment.

Enhanced durability of therevetment was achieved usingSTRUX 90/40 reinforcement inplace of steel reinforcement.Similarly, use of novel polymerreinforcement in the precastelements offered majorconstruction enhancements. This

was the first time these materialshad been used on this scale in theUK.

It won the North West CivilEngineering Large Project of theYear for 2011



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Bridges Wharf Car Park, London, UKSTRUX Project Profile

Product: STRUX 90/40 & ADVAFloor 250

Application: Concrete Topping

Engineer: Waterman Group

Main Contractor: Westcrete

Specialist Floor Layer: Technic

The Engineers brief was toprovide a solution to reduce therisk of corrosion that could becomean issue if traditional steel fabricwas used in the concrete for the

car park areas within this privatedevelopment and reduce theamount of joints.

Grace worked closely with allparties on the project to assist withproviding a detailed design solutionwhile also working with thecontracts team to assist with mix

design and placement advice.

ADVA Floor 250 & STRUX 90/40placed on top of the HydroductCF20 was a major benefit to theEngineer in reducing any exposureto remedial or repair costs.



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Summary:

STRUX synthetic macro fibres provide:

Comparable crack control to steel fabric and steel fibres

No corrosion issues

Reinforcement is delivered and poured with concrete always in the right place

3 dimensional reinforcement

Reduced project costs

Reduced project times

Safer construction environment

Pedigree Credibility


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Durabili ty Products Contacts EMEAI Region

Contact Name Gerard Attree

Contact Title Engineering Services Group Manager

Contact Phone Number +44 (0) 7808 635229

Contact Email Address [email protected]


Thank you for your attention, any questions?
mailto:[email protected]:[email protected]

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