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Fiber Reinforced Conrete
Alice DemenyiHenrik Jonestrand
Eva Pratschke
140.804 New Materials and Methods of Building Supporting Structures
Fiber Reinforced Conrete
TIMELINE
The concept of using fibers as reinforcement is not new. Fibers have been used as reinforcement since ancient times. Historically organic fibers from horsehair was used in mortar and grass straws were mold into mud bricks to increase the strength.
In the early 1900s, asbestos fibers were used in concrete. A half century later the 1950s the concept of composite materials came into being. Fiber reinforced concrete was one of the topics of interest. There was a need to find a replacement for the asbestos used in concrete and other building materials once the health risks associated with the substance were discovered.
By the 1960s, steel, glass (GFRC), and synthetic fibers such as polypropylene fibers were used in concrete, and research into new fiber reinforced concretes continues today.
1900 1950 1960
Asbestos Fiber
Ancient
Organic FiberHorsehair / GrassIn morts and bricks
Glass FiberSteel FiberSynthetic Fiber
1990
Carbon FiberCompositesinvented
HISTORY
Mud bricks with organic fibers
APPLICATIONS• Facade Panels• Shotcrete / Underground Concrete (Tunnels for
example)• Precast Concrete• Commercial Slabs
BENEFITSIncreases the tensile strength of the concrete.
Reduces the air voids and water voids the inherent porosity of gel.
Increases the durability of the concrete.
Fibres such as graphite and glass have excellent resistance to creep, while the same is not true for most resins. Therefore, the orientation and volume of fibres have a significant influence on the creep performance of rebars/tendons.
Reinforced concrete itself is a composite material, where the reinforcement acts as the strengthening fibre and the concrete as the matrix. It is therefore imperative that the behavior under thermal stresses for the two materials be similar so that the differential deformations of concrete and the reinforcement are minimized.
It has been recognized that the addition of small, closely spaced and uniformly dispersed fibers to concrete would act as crack arrester and would substantially improve its static and dynamic properties.
Fiber Reinforced Conrete
• Uniformly Distributed Fibers• Possible to cast very thin elements
70-90% thinner compared to normal concrete• More fluid than normal concrete
COMPARISON OF SHORT FIBER TYPES
Fiber Reinforced Conrete
ACRYLIC
ASBESTOS
CARBON*
AR GLAS
POLYETHYLENE*
STEEL
DIAMETER
ACRY
LIC
ASBE
STO
S
CARB
ON
MIT
SUI
CARB
ON
PAN
CARB
ON
PITC
H
AR G
LASS
POLY
ETHY
LENE
POLY
VINY
LAL
COHO
L
FIBR
ILLA
TED
POLY
PRO
PYLE
NE
STEE
L
Fiber Reinforced Conrete
18 2010
0.5
18
60
90
200 600
µm
Fiber Reinforced Conrete
ACRY
LIC
ASBE
STO
S
CARB
ON
MIT
SUI
CARB
ON
PAN
CARB
ON
PITC
H
AR G
LASS
POLY
ETHY
LENE
POLY
VINY
LAL
COHO
L
FIBR
ILLA
TED
POLY
PRO
PYLE
NE
STEE
L
SPECIFIC GRAVITY
1.18
3.5
1.6 2 1.72.7
0.91.4
0.9
7.8
kg/m3
ACRY
LIC
ASBE
STO
S
CARB
ON
MIT
SUI
CARB
ON
PAN
CARB
ON
PITC
H
AR G
LASS
POLY
ETHY
LENE
POLY
VINY
LAL
COHO
L
FIBR
ILLA
TED
POLY
PRO
PYLE
NE
STEE
L
TENSILE STRENGTHFiber Reinforced Conrete
1
3.5
1
3.6
1.72.5
0.2 0.150.7
2.0
GPa
ACRY
LIC
ASBE
STO
S
CARB
ON
MIT
SUI
CARB
ON
PAN
CARB
ON
PITC
H
AR G
LASS
POLY
ETHY
LENE
POLY
VINY
LAL
COHO
L
FIBR
ILLA
TED
POLY
PRO
PYLE
NE
STEE
L
TENSILE MODULUS(STIFFNESS)
Fiber Reinforced Conrete
GPa20
190
75
400
32
70
2.512.5
10
200
ACRY
LIC
ASBE
STO
S
CARB
ON
MIT
SUI
CARB
ON
PAN
CARB
ON
PITC
H
AR G
LASS
POLY
ETHY
LENE
POLY
VINY
LAL
COHO
L
FIBR
ILLA
TED
POLY
PRO
PYLE
NE
STEE
L
STRAIN TO FAILURE
%
Fiber Reinforced Conrete
11
3 31.5 5 3.6
10 118
3.5
_a composite of high strength glass fiber [alkali resistant glass fibers]embedded in a polymer concrete matrix_the fibers are the principal load-carrying members, transfer loads from one fiber to another via shear stresses through the matrix
STRUCTURAL PROPERTIES OF GFRC
_shape flexibility > used for complex, three dimensional shells where loads are light_durability expected to last as long as pre-cast concrete [in environments, as when exposed to salt spray or high moisture, the GFRC can be expected to perform better, as there is no steel reinforcement to corrode]_made of minerals > not burning, acts likes a thermal regulator when exposed to flame [it also protects the materials behind it from the heat of the flame]_the orientation of the fiber determines how effective that fiber resists the load [the more ran-dom the orientation, the more fibers are needed to resist the load]_typical GFRC mix uses a high loading of glass fibers to provide sufficient material cross-sec-tional area to resist the anticipated tensile loads [a loading of 5% fiber by weight of cementitious material is used]
GLASS FIBER REINFORCED CONCRETE [GFRC]
random, three-dimensional (3D) reinforcing random, two-dimensional (2D) reinforcing one-dimensional (1D) reinforcing
LEVELS OF REINFORCEMENT
Fiber Reinforced Conrete
Laminates_ adhering and consolidating thin layers of fibers and matrix into the desired thickness_the fiber orientation in each layer as well as the stacking sequence of various layers can be controlled to generate a wide range of physical and mechanical properties for the composite laminate
APPLICATIONS
Sandwich panels_composite of three or more materials bonded together to form a structural panel_it takes advantage of the shear strength of a low density core material and the high com-pressive and tensile strengths of the GFRC facing to obtain high strength to weight ratios_sandwich panels and functions of the individual components may be described by making an analogy to an I-beam
Spray-up_spray-up is similar to shotcrete in that the fluid concrete mixture is sprayed into the forms _the concrete and fibers mix when they hit the form surface_typically Spray-up is applied in two layers
Premix_ involves mixing shorter fibers in lower doses into the fluid concrete_this mixture is either poured into molds or sprayed_tends to be less strong than spray-up due to the shorter fibers and more random fiber orienta-tion
CASTING METHODS
Fiber Reinforced Conrete
L Oceanica Valencia - Steel Fiber Reinforced Concrete 6cm thick shells
Fiber Reinforced Conrete
Negative Formwork
Structure under the Formwork
Year 1999 Valencia, SpainStatus CompletedClient Ciudad de las Artes y las Ciencias S.A.Floor Area 1,200 m2Budget 1.500.000 EurosMaterial Steel Fiber Reinforced Concrete (6cm)
Fiber Reinforced Conrete
Zaha Hadid - Zaragoza Bridge - Glass Fiber Reinforced Facade Panels
Fiber Reinforced Conrete
Zaha Hadid Roca London Gallery - Glass Fiber Reenforced Concrete
Renovation of 1984 National Soccer Stadium of South Africa
Glass Fiber Reinforced ConcreteFacade Panels
Colored with Lanxess Pigment
Populous ArchitectsBoogertman Urban Edge + Partners
Fiber Reinforced Conrete
National SoccerStadium South Africa 1988- Steel Fiber Reenforced Concrete
Fiber Reinforced Conrete
National SoccerStadium South Africa 1988- Steel Fiber Reenforced Concrete
Fiber Reinforced Conrete
Zaha Hadid Roca London Gallery - Steel Fiber Reenforced Concrete
PropertiesDecorative, luminous, strong
AppicationInterior architecture and signage
Technical SpecificationsDimension 500 x 1000mm up to 1000 x 1500mmDensity ca. 2300 kg/mColours white or grey
_translucent, multi-layered concrete_surfaces are polished to a shiny finish and impregnated with a water repellent_the fibers are arranged [woven]in the concrete so as to cre-ate a motif / pattern or a luminous message_a light source is place behind the devise to energise the component
CONCRETE WITH OPTICAL FIBERS
Fiber Reinforced Conrete
PropertiesTranslucent, fine thickness, decorative and flexible
AppicationAutomotive and yacht engineering, room furnishings and decor
Technical SpecificationsMax dimension 100 x 50cmThikness 0.8mm a film sublayer allows 3d shape creation
_composition: layers of concrete and optical fiber _high UV resistance _can be cutted, glued, perforated
CONCRETE AND QUARZ OPTICAL FIBER
Fiber Reinforced Conrete
Fiber Reinforced Conrete
1) Wilkins, Dick J. (ed.), JTEC Panel Report on Advanced Manufacturing Technology for Polymer Composite Structures in Japan, Japanese Technology Evaluation Center, Baltimore, MD, NTIS PB94-161403, April 1994. (http://itri.loyola.edu/polymers/).
BIBLIOGRAPHY