Composite Materials: RCC, FRC, steel/concrete composite bridge decks, fibre reinforced plastics structural insulated panels.

1. MODULE-III
Prepared by-
Prof. Basweshwar S.J.

2. COMPOSITE MATERIALS
Composites are combinations of two more separate materials on a microscopic
level, in a controlled manner to give desired properties.
The properties of a composite will be different from those of the constituents in
isolation.
When two materials are combined together to form a composite, one of the
materials will be in
“Reinforcing phase” and
“Matrix phase”.
• Reinforcing material in the form of fibres, sheets or particles are strong with low
densities.
• The matrix is usually a ductile or tough material.
Eg.: Glass -> Reinforcing material
Polyester -> Matrix material
Glass + Polyester -> GRP (Glass fibre reinforced plastic)
Prepared by-
Prof. Basweshwar S.J.

3. CLASSIFICATION
Composites can be broadly classified in to two groups. They are,
1. Natural composites
2. Man-made composites
Several natural materials can be grouped under natural composites.
Eg.: Bone, Wood etc.,
Man-made composites are produced by combining two or more materials in definite proportions under
controlled conditions.
Eg.: 1. Mud mixed straw to produce stronger mud mortar and bricks.
2. Ferro-cement
3. Concrete and RCC
4. Plywood, Chipboards, Decorative laminates
5. Reinforced Glass
6. Fibre Reinforced Plastic (FRP)
Prepared by-
Prof. Basweshwar S.J.

4. PROPERTIES OF COMPOSITES
1. Composites posses excellent strength and stiffness
2. They are very light materials
3. They possess high resistance to corrosion, chemicals and other weathering agents.
4. They can be moulded to any shape and size with required mechanical properties in different directions.
Disadvantages of composites
1. High production cost
2. Difficult to repair
3. Susceptible to damage
Uses of composite materials
1. Extensively used in space technology and production of commercial air-planes.
2. Used in the production of sport goods.
3. Used for general industrial and engineering structures
4. Used in high speed and fuel efficient transport vehicles
Prepared by-
Prof. Basweshwar S.J.

5. APPLICATIONS IN THE FIELD OF CIVIL ENGINEERING
• Composites are extensively used in the field of Civil Engineering.
• Ferro-cement is a good example for composite.
• R.C.C. and P.S.C. (Pre-stressed Cement Concrete) are composites that are
widely used for structural components.
• Even concrete can be considered as a composite.
• Block boards, Batten boards, and Chip boards which are composites are used
in light construction works such as doors, windows, furniture and cabinets.
Asbestos Cement Sheets are used as roofing material.
• Reinforced glass is used for sky-lights and door and window panelling.
Prepared by-
Prof. Basweshwar S.J.

6. RCC
• Reinforced concrete (RC) (also called reinforced cement concrete or RCC) is a
composite material in which concrete's relatively low tensile strength and
ductility are counteracted by the inclusion of reinforcement having higher
tensile strength or ductility.
• The reinforcement is usually, though not necessarily, steel reinforcing bars
(rebar) and is usually embedded passively in the concrete before the
concrete sets.
• Reinforcing schemes are generally designed to resist tensile stresses in
particular regions of the concrete that might cause unacceptable cracking
and/or structural failure. Prepared by-
Prof. Basweshwar S.J.

7. PROPERTIES
• High relative strength
• High toleration of tensile strain
• Good bond to the concrete, irrespective of pH,
moisture, and similar factors
• Thermal compatibility, not causing unacceptable
stresses (such as expansion or contraction) in response
to changing temperatures.
• Durability in the concrete environment, irrespective of
corrosion or sustained stress for example.
Prepared by-
Prof. Basweshwar S.J.

8. FRC
• Fiber Reinforced Concrete can be defined as a composite material
consisting of mixtures of cement, mortar or concrete and discontinuous,
discrete, uniformly dispersed suitable fibers.
• Fiber reinforced concrete are of different types and properties with many
advantages.
• Continuous meshes, woven fabrics and long wires or rods are not
considered to be discrete fibers.
Prepared by-
Prof. Basweshwar S.J.

9. NECESSITY OF FIBER REINFORCED CONCRETE
• It increases the tensile strength of the concrete.
• It reduce the air voids and water voids the inherent porosity of gel.
• It increases the durability of the concrete.
Prepared by-
Prof. Basweshwar S.J.

10. STEEL/CONCRETE COMPOSITE BRIDGE DECKS
Prepared by-
Prof. Basweshwar S.J.

11. STEEL/CONCRETE COMPOSITE BRIDGE
DECKS
Prepared by-
Prof. Basweshwar S.J.

12. FIBRE REINFORCED PLASTICS
STRUCTURAL INSULATED PANELS
Prepared by-
Prof. Basweshwar S.J.