2. CONTENTS
Introduction
What is bendable concrete ?
Materials used in bendable concrete
Advantages of bendable concrete
Disadvantages of bendable concrete
Applications of bendable concrete
conclusion
3. INTRODUCTION
Concrete is widely used in today’s construction industry . it has good load
bearing capacity. it can take the compressive load very effectively . But the
main problem with the traditional concrete is that it cannot take much
tensile stress. It fails under the tensile load . The bendable concrete is a
good substitute for this problem.
Bendable concrete is a class of ultra- ductile fibre reinforced cementitious
composites , characterized by high ductility and tight crack with control.
This material is capable to exhibit considerably enhanced flexibility .
5. The recently developed smart building material namely bendable concrete also
known as flexible concrete or engineered cementitious composite (ECE).
it is a special type of concrete that can take the bending stresses .it consist of
special type of materials that makes it flexible.
Bendable concrete is class of ultra – ductile fibre reinforced cementitious
composites ,characterized by high ductility and tight crack width control.
6. MATERIALS USED IN BENDABLE CONCRETE
1. FIBRES REINFORCEMENT
Bendable concrete is composed of all the ingredients of a traditional
concrete minus coarse aggregates and instead we use the fibres that
are used in the fibre reinforced concrete such as silica fibres , glass fibres
,steel fibres ,asbestos fibres etc.
2 SLICK COATING ( ANTI – FRICTION COATING)
This tendency of slipping of fibres over one another helps the concrete to
minimize the crack and provide flexibility to the concrete . The normal
cement can be used for the concrete .
7. 3. FINE SAND
the fine silica sand is suitable for the bendable concrete which is used in the water treatment plant but if it
not available the normal sand can be used but it may effects the strength and flexibility of concrete ,fly ash
silica fume ,blast furnace slag can also be used in the concrete.
8. 4. Superplasticizer
latex can also be used in the concrete for improving its flexibility.
polycarboxylate ether, lignosulfonates ,lignin ,naphthalene or melamine formal
dehyde sulphonate ( anyone ) is used in the concrete for increasing the workability
Of concrete .
9. Advantages of bendable concrete
It is more resistant to cracking .
It is more stronger, more durable , and lasts longer than
conventional concrete.
It reduces the cost of the project .
It can be used as precast concrete .
flexible concrete is approx 20 – 40 % lighter.
The use of steel reinforcement is reduced and can be eliminated .
10. Disadvantages of bendable concrete
It requires skilled labour for its construction.
Its needs some special type of materials which can be difficult to find
in some areas .
It has a high initial cost as compared to conventional concrete.
Its quality depends upon the material used and the condition under
which it is made.
11. APPLICATIONS
In the construction of the jointless bridges.
In earth quake resistant structures.
In flexible concrete roads and bridges there is no need of joints
such as expansion joints ,contraction joint as the ECC itself has
ability to change its shape .
construction of concrete canvas.
14. Conclusion
Compressive strength decrease with the increase in the increase
in the cementitious material i.e fly ash , silca fume .
Increasing the specimen size and exposure temperature
decreased the compressive strength and stiffness.
The water to cementitious material (w/c) ratio 0.27 gives the best
results .