This is a powerpoint presentation on self healing concrete. I got 2nd prize in inter college paper presentation event through this ppt.

1. RAJ KUMAR GOEL INSTITUTE
OF TECHNOLOGY
PRESENTATION ON BACTERIAL CONCRETE
PRESENTED BY:- RATNESH KUSHWAHA
ROLL NO:-1503300075

2. INTRODUCTION
Crack formation is a typical phenomenon related to
durability.
Percolation of cracks may lead to leakage problems,
causing deterioration of the concrete matrix or
corrosion of embedded steel reinforcement.
In recent years a bacteria-based self-healing concrete
is being developed in order to extend the service life.
A two component healing agent is added to the
concrete mixture.
The agent consists of bacteria and an organic mineral
precursor compound.

3. WHAT IS BACTERIAL CONCRETE
 Bacterial concrete is also called as self
healing concrete.
 It is a special type of concrete which is
cement based material that repair
themselves after the material or
structure gets damaged due to some sort
of deterioration mechanism.
 It is specially made to increase the
lifespan or the durability of concrete
structure by the self healing action of
concrete.

4. WHAT SPECIAL PRESENT IN BACTERIAL CONCRETE
There are two things present in bacterial concrete-
1) The special bacteria that has to resist the alkalinity and
the mechanical stress of concrete.
2) The chemical precursor to activate the bacteria.

5. WHAT BACTERIA IS USED
 Most of the bacteria belongs to genus bacillus are fulfilling the
required criteria discussed above. Some of the list of the
bacteria are Bacillus. Pseudofirmus,
 B.Cohnii B.Filla B.Pasteurii…..etc
 The chemical precursor found to be most suitable is ‘calcium
lactate’ Ca(C3H5O2)2

6. WHAT IS HAPPENING INSIDE BACTERIAL CONCRETE(MECHANISM)
 The cracks are formed on the surface of concrete due to any
reasons like shrinkage ,inadequate water for hydration…etc.
 The water is deliberately forced into the crack and the
precursor is activated.

7.  The chemical precursor activates the bacteria to react with
that precursor and form a base of calcium carbonate called
as lime stone ,the chemical equation is given below .
Ca(C3H5O2)+7O2 CaCO3+5CO2+5H2O
CO2+ Ca(C3H5O2) CaCO3+H2O
(Carbonation)

8. PICTURE OF HEALING
Before healing After healing

9. LIMITATIONS
 During the study it was found that no strong spores were
detected in a 135 days old specimen, implying the
majority of the spores in the cured cement mixture were
available for less than 4 months.
 The bio concrete is very expensive and is about double
cost of conventional concrete. However if the lifespan of
structure can be increased upto 30% it will automatically
bring down its cost in the longer term

10. EVALUATION
 The concrete properties should not be negatively affected
by addition of healing agent to the concrete mixture .
 A large amount of bacteria and certain mineral precursor
compounds like calcium lactate do substantially influence
concrete compressive and tensile strength .
 Further research is needed to increase the time period
that the bacterial spores remain in the concrete and also
to make bacterial concrete feasible by decreasing its
manufacturing cost.