Participants Names: B.ANAND & D.C.NAVEEN

College Name : Indira Institute of Engineering & Technology, Tiruvallur.602001

Title of the paper: “DUCTAL CONCRETE - A High

Performance Construction Material”

Contact Number: 9994765325

9842176424

Mail : anand19civil@gmail.com

naveencivil24@gmail.com

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DUCTAL CONCRETE

(A High Performance Construction Material)

ABSTRACT

Now a days we are expecting high performance in all the fields of work which does

not exclude concrete also. At an estimated rate of 5 billion cubic yards per year, concrete is the

second most widely consumed substance on earth, surpassed only by water. Our innovative

thinking and modern construction techniques leads to the emerging of high performance

concrete. one such advancements in ultra high performance concrete is DUCTAL concrete.

What is your idea of the perfect building material? Would it have the strength of steel?

The versatility of concrete? The flexibility of plastic or wood? The durability of stone? The

aesthetic richness of ceramics? What if you could get it all-in-one and customize the properties

to suit your project? With Ductal, you can combine all of these! Unlike any other material, it

combines superior properties that provides engineers, architects, artists and users with new

freedom to design innovative solutions and to DO MORE WITH LESS. In this paper we

discussed about the principles, characteristics, types, performance and advantages of the ductal

concrete compared to conventional one.

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INTRODUCTION

Ultra-high performance concrete is a new cementitious material with strength more than

150 N/mm² and other perfect properties. Basic principle to improve the concrete properties is the

reduction of defect places, such as micro cracks and capillary pores. Ductal concrete is one such

high-performance construction material by Lafarge that may create new possibilities for the

world of decorative concrete. Ductal, a revolutionary, ultra-high-performance material that

delivers up to 30,000 psi compressive strength and rivals the strength of metal. . This is closely

related to the material's amazing ability to bend (within limits) without breaking - a property

called "ductility" and the inspiration for its name. The material's strength enables it to be used in

very thin sections. This, in turn, reduces the self weight of a structure and allows the use of larger

pieces with fewer joints and hence it pays way for the innovative construction.

WHAT IS DUCTAL?

Ductal is a new revolutionary ultra-high performance concrete material that offers a

unique combination of superior characteristics including strength, durability, aesthetics and

ductility. Ductal concrete incorporates strengthening fibers and opens the horizon to ultra-high

performances.

KEY PRINCIPLES OF THE DUCTAL TECHNOLOGY

Ductal’s superior technical characteristics are due to the following four principles

Reactive Gradation

Ductility

Rheology

Aesthetics

REACTIVE GRADATION PRINCIPLE

The raw materials in Ductal are selected for their complimentary properties of size,

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shape and chemical reactivity. Ductal uses "modified compact grading" to promote a highly

effective fiber-matrix interaction. It is made without large aggregates, and all the mineral

components are in the sand-size range.

COMPONENTS

Cement

Silica fume

Mineral fillers(nano fibers)

Water

Fibers(metallic or organic)

Sand

Superplasticizer

Microscopic view of ductal concrete

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Comparison of gradation

DUCTILITY PRINCIPLE

Ductal derives its name from the word "ductility" which means that, unlike

other brittle materials, it has the ability to deform while continuing to carry loads - even after the

first sign of cracking. Its ductile behaviour was developed from a thorough understanding of the

fibre-matrix interaction. The fibre-matrix slippage/breakage ratio during loading and over-

loading provides a ductile behaviour with finely and well-dispersed micro cracking, unlike

conventional concrete or fibre-reinforced cements.

RHEOLOGY PRINCIPLE

A key property of Ductal is its ability to have a range of fluidities from virtually self-

placing to dry-cast. Lafarge has developed a formulation model based on years of research and a

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thorough understanding of the interactions between cements – Silica Fumes and

Superplasticizers. The result is a range of products with properties specifically formulated to

each customer’s requirements.

AESTHETIC PRINCIPLE

Like a chameleon, Ductal has the ability to replicate the surface texture and shape of

the mould. This feature is a result of the use of very fine powders and the fluidity, combined with

Ductal’s ability to be colored, gives artists and architects a new material with superior surface

aspect and high aesthetic appeal.

Ductal concrete in different colors and textures

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HISTORY AND EVOLUTION

Ductal is a story of change and innovation. Researchers at Lafarge and partners,

Bouygues and Rhodia developed Ductal, a material that provides a unique combination of

superior strength, ductility, durability and aesthetics compared to traditional materials like

concrete, steel, wood and plastics. Following more than a decade of research by a large multi-

discipline team, four patents have been taken between 1994 and 2001.

Ductal is constantly breaking new ground with architectural and engineering firms in

Europe and prototypes were first introduced to North America in 1998. Today, this ultra-high

performance ductile material is providing new, innovative solutions to old problems; solutions

that reduce the global cost of construction by using less materials, faster construction, reduced

labour, reduced maintenance and increased usage life.

TYPICAL CHARACTERISTICS:

Ductal is an ultra-high performance material with ductility, utilizing metallic or organic

fibres. It is mouldable in the form of dry-cast, fluid or self-consolidating with properties

adaptable to the demands of each application. Available in custom-blended 80 lb paper bags or

1,000 - 2,000 lb bulk bags, depending on the type of fiber required (metal or organic).

STRENGTH:

Compressive * 24,000 - 33,000 PSI 160 - 230 MPa

Flexural * 4,500 - 7,200 PSI 30 - 50 MPa

Youngs Modulus (E) 8 - 8.5 x 106 PSI 55 - 60 GPa

Total Fracture Energy 1,300 - 2,000 lb (F)-ft/ft2 20,000 – 30,000 J/m2

Elastic Fracture Energy 1.4 - 2.1 lb (F)-ft/ft2 20 - 30 J/m2

* For characteristic design properties

RHEOLOGY:

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Fluid to self-compacting:

Flow (Abrams cone) 20 - 30 inches 50 - 70 cm

Flow (ASTM shock table) 10 inches 25 cm

DURABILITY:

Chloride ion diffusion (C1) 0.02 x 10-11 ft2/s

Carbonation penetration depth <0.02 inches

Freeze/thaw (after 300 cycles) 100%

Salt-scaling (loss of residue) <0.0025 lb/ft2

Abrasion (relative volume loss index) 1.2

OTHER CHARACTERS:

Density 2.45 – 2.55

Entrapped air content 2 - 4%

Capillary porosity (>10 mm) <1%

Total porosity 2 - 6%

Post cure shrinkage 0

Creep coefficient 0.2 - 0.5

PRE-MIX:

Ductal can be mixed in a normal industrial concrete mixer. The use of a pre-mix

simplifies the batching sequence and the length of mixing time.

PLACING:

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Ductal is adaptable to any placing technique such as Cast-in-place, pumping, injection,

extrusion etc…

CURING:

Normal curing at 70° F (20° C) produces the following performances:

24 hours after initial set: fc> 15,000 PSI 100 MPa

at 28 days: fc> 25,000 PSI 180 MPa

A thermal treatment of 195° F (90° C) applied after final set produces up to 33,000 PSI (230

MPa) in 4 days.

MOULDING :

Texture: The fineness of the materials and the fluidity of the mix provide a material

with a high ability to replicate the micro-texture of the form surface or special mould textures. it

can be moulded in to any shape depending on our requirement as it has the ability to bend which

makes it unique in its character when compared to other.

COLORS:

Light grey to black and available in a variety of colors upon request. It is just like a

chameleon what ever we apply to it we will get back the same. it has the ability to absorb what

ever the color we apply.

PRE-STRESSING:

There is no need to reinforce with passive reinforcing bars normally used in reinforced

concrete. Ductal’s mechanical properties are even further increased by the use of pre-stressing

(pre or post-tension). The strength of Ductal allows for solutions to be

designed with smaller elements, without the use of passive reinforcement (reinforcing steel) and,

in most applications, without pre-stressed or post tensioned reinforcement.

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TYPES OF DUCTAL CONCRETE:

Ductal an ultra high performance concrete is basically classified in to

Ductal with organic fibres

Ductal with metallic fibres

Organic fibers are typically used where human contact is expected because the steel

fibers are extremely small (0.2 mm diameter, 13 mm long) and can easily puncture human skin.

ORGANIC FIBRES METALLIC FIBRES

Compressive 17000 – 22000 psi 23000 – 33000 psi

Flexural 2200 – 3600 psi 4000 – 7200 psi

Youngs Modulus (E) 6500 – 7200 ksi 8 – 8.5 x 106 psi

Density 2.2 – 2.4 2.45 – 2.55

Capillary porosity <1% <1%

Total porosity 3 – 6% 2 – 6%

COMPARISON BETWEEN DUCTAL WITH ORGANIC FIBRES AND

METALLIC FIBRES

PERFORMANCE:

Under extreme load, this ductile concrete behaves similar to steel by bending rather

than cracking. Its ductile behavior comes from well-dispersed micro-cracking which makes good

use of the fiber-matrix interaction and its slippage/breakage ratio. Simply put, the micro-cracking

of the more brittle cement matrix engages the more ductile fibers in resisting the load.

Because of the modified compact grading used in Ductal formulations, its surface is

very dense, which also reduces its porosity and improves its resistance to abrasion, scratching,

and pollution. To further enhance its durability, increase mechanical properties, and maximize

dimensional stability, Ductal can be heat-treated.

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INNOVATIVE FEATURES:

Ductal’s unique combination of superior properties enabled the designer to create thinner

sections and longer spans for a tall structures.

This is the first known use of UHPC used in a long-span roof system.

No need of use of steel reinforcements

The lightweight system did not impact the foundation design.

Reduction in non-renewable resources: due to a reduction in the total quantity of

materials consumed and the use of recycled materials in Ductal (such as Silica Fume).

The Ductal is air and water-tight, thereby resulting in reduced environmental impact

and reduced maintenance.

Due to the lightweight design, the precast panels were easily transported

The ductile behavior of this material is a first for concrete. It has the capacity to deform

and support flexural and tensile loads, even after initial cracking.

DUCTAL PROJECTS: PAST, PRESENT AND FUTURE:

To date, Ductal has been used for a number of innovative solutions including projects

such as: acoustic sound panels, seawall and bridge anchor plates and beams for a power plant

cooling tower. In Seoul, Korea, a pedestrian bridge named “The Footbridge

of Peace”, has a 425′ (130 m) arch constructed entirely with Ductal. Considered a building feat,

the bridge has no middle supports and a platform thickness of just 3cm.

In North America, Ductal products are supplied by Lafarge and custom formulated for

each new application or project. Currently the team is focusing efforts on priority target markets

with a medium to long-term strategy geared towards applications

such as structural wall panels, leave-in-place forms, poles/piles, seismic elements and bridges.

CASE STUDY ON DUCTAL MADE SHERBROOKE BRIDGE

Project Location: Sherbrooke, Quebec, Canada

Contractor: Pomerleau

Precaster: Béton Bolduc

Ductal Volume: 42 m3

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Constructed

with Ductal,

this pedestrian

bridge spans

60 m (190 ft)

with a deck

thickness of

just 3 cm (1¼").

This project features several technological innovations:

Absence of passive reinforcements

Miniaturized pre-stressing

diagonals in confined ductal

CONCLUSION:

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Clearly, this ductile concrete will be the exciting news for leading-edge structural

engineers and architects who challenge themselves to "do more with less." It should be exciting

news, too, for everyone interested in decorative concrete. That's because the performance of the

new material demands a reassessment of the aesthetic and functional possibilities of concrete

construction. And it is so durable that it can be used without fear of the elements for enduring

structures and monuments. Further research is going on this and it will surely make revolution in

concrete world.

REFERENCE:

www.imagineductal.com

www.lafragenorthamerica.com

Journal of New construction and building materials

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