2. PERFORMANCE AND EVALUATION
OF BACTERIAL CONCRETE
Presented By:
Kuntal Banerjee
Abhijit Mandlik
Sharique Anwar
Manish Chavan
Md. Zeeshan
Under Guidance:
Mr. Pravin Gorde
(Asst. Prof., D.Y.P.I.E.M.R)
3. INTRODUCTION
Bacterial concrete is also called as Self healing concrete or
Microbial concrete.
This is a combined study of Micro biology as well as
concrete technology.
As the name suggests self healing concrete is one that can
sense its crack formation and can react to cure itself
without any kind of human intervention.
It is a type of concrete that can biologically produce
limestone to heal the cracks that appear on the surface of
any concrete structure.
Major drawback of concrete is that it fails in tension upon
sustained loading.
4. Contd....
Synthetic materials like epoxies are used for remediation.
Thus, Bacterial induced Calcite precipitation has been
proposed as an alternative and environment friendly crack
remediation.
Cracks in concrete significantly influence the durability
characteristics of the structure. The bacterial remediation
technique can be used for repairing structures of historical
importance to preserve the aesthetics value.
Tests are conducted to study the mechanical properties of
the above concrete with various percentages of Bacteria.
The tests carried out are Compressive strength test, S.E.M
Test, Flexural test.
5. Contd....
Some possible mechanisms of a Self-healing concrete are:
1. Formation of material like calcite.
2. Blocking of the path by sedimentation of particles.
3. Continued hydration of cement particles.
4. Swelling of the surrounding cement matrix.
Also the common categories that the bacteria is
categorized are as follows:
1. Bacillus
2. E.Coli
3. Fungus
4. Urease, etc.
6. CLASSIFICATION OF BACTERIA
Generally classified into 3 categories:
1.On the basis of shape {e.g. spirilla, bacilli, cocci}.
2.On the basis of gram strain {e.g. gram positive and gram negative}.
3.On the basis of oxygen demand {e.g. aerobic and anaerobic}.
These classification is irrespective of the bacteria categorization.
Various types of bacteria used in construction area are
Bacillus
pasteurii
Escherichia
coli
Bacillus
subtilis
Bacillus
sphaericus
Bacillus
pseudifirmus
8. Objectives:
Optimization of Bacterial Density.
Comparing Compressive Strength of Normal concrete,
Concrete with E-coli, and Concrete with Bacillus subtilis.
Performing sustainability tests like Water permeability,
Scanning Electron Microscope (S.E.M).
Comparing Split Tensile strength of Normal concrete,
Concrete with E-coli, and Concrete with Bacillus subtilis.
9. Characteristics of Bacillus
Rods 0.6-0.9*1.5-3.5 microns with rounded ends, usually
not in chains, gram positive.
Spores are 1-1.2 microns in diameter, round and terminal to
sub terminal.
The colonies are usually circular and glossy, however the
size and opacity arises from media to media.
Urea-agar slant shows thin growth i.e. restricted and
translucent.
Urea-milk-agar streak plate shows variable hydrolysis of
casein.
10. Methods For Insertion
Bacteria inserted in the concrete is done by the following
method:
In this process, the mixing of the cement, water and
aggregates are done using bacterial water itself instead of
using normal water.
This process is just a variant from the 3 basic insertion
process.
12. WORKING OF BACTERIA ON
CONCRETE
Upon exposure to environment, the spores of bacteria
germinate on contact with water and nutrients.
Bacteria start to feed on calcium lactate when activated
Oxygen is consumed and soluble calcium lactate is
converted to insoluble limestone.
The limestone solidifies on the cracked surface, thereby
sealing it up.
Consumption of oxygen also increases the durability of
steel reinforced concrete constructions.
Following diagram shows the complete healing process of
the concrete under effect of bacteria.
14. How Does Bacteria Enhances a
Concrete Performance
Bacteria are exposed to the air and the food, the bacteria
grow through the bio chemical process that causes them to
harden and fuse, strengthening the structure of concrete.
This process extends the lifespan the concrete. Mixing the
bacteria with concrete the bacteria transmits into dormant
state.
If any minor damage or crack is found in the concrete, the
bacteria provides space for water or air entry within
concrete.
To create an alkaline environment through various
physiological activities.
15. Contd....
Calcium carbonate precipitation is a straight forward Chemical process
governed mainly by four key factors:
(1) The calcium concentration.
(2) The concentration of dissolved inorganic carbon (DIC).
(3) The pH.
(4) The availability of bacterial sites.
17. ADVANTAGES
Formation of crack will be healed in the initial stages itself thereby
increasing the service life of structure.
Reduction in permeability of concrete.
Reduction in corrosion of reinforced concrete.
Less maintenance and repair cost of steel reinforced concrete structure.
18. DIS-ADVANTAGES
Cost of bacterial concrete is more than that of conventional concrete.
Growth of bacteria is not good in any atmosphere and media.
No specific IS code for mix concrete.
Investigation of calcite precipitation is costly studied.
20. APPLICATION MICROORGANISM METABOLISM NUTRIENTS
Biological mortar Bacillus cereus Oxidative
deamination of
amino acids
Peptone,
Extract yeast,
cacl2.2H2O.
Crack in concrete
remediation
Bacillus subtilis Hydrolysis of urea Nutrient broth,
urea,
cacl2.2H2O.
Crack in concrete
remediation
Bacillus sphaericus Hydrolysis of urea Extract yeast,
urea,
cacl2.2H2O
Bacterial concrete Bacillus subtilis Hydrolysis of urea Nutrient broth,
urea,
cacl2.2H2O.
Bacterial concrete Bacillus subtilis Oxidative
deamination of
amino acids
Peptone,
Nacl,
yeast extract
21. LITERATURE SURVEY
Henk Jonkers, has published a paper on Bacteria-based
self-healing concrete. In this paper the author has
described about the action of bacteria after the insertion
into the concrete. Viable bacteria as self-healing agent and
the autonomous crack healing system of self healing agent
are the two main points that have been focused in this
paper.
Srinivasa Reddy, has published a paper on Bacterial
Concrete. In this stated paper the bacteria used is bacteria
Subtilis and the physical and chemical transformation of
the concrete at high temperatures have been shown. The
behaviour of concrete subjected to high temperatures
depends on many factors such as member size, heating
rate, peak temperatures, dehydration of C–S–H gel, phase
transformations, and thermal incompatibility between
aggregates and cement paste.
22. Contd...
Dr. Nele De Belie, has published a paper on Healing and
Self-Healing of Concrete,has shown during their
presentation how repair and consolidation of mineral
phases of building materials and the healing and self-
healing of concrete with the help of bacteria is possible.
Micro-organisms play a crucial role in pedogenesis,
transformation of minerals and exchange of elements in
structures.
Kantha D.Arunachalam, has published a article on
Biosealant properties of Bacillus sphaericus in which they
say Bacillus spharecius was yet another partially
characterized species with similar entity, having the
capability of precipitating calcium carbonate. Bacillus
spharecius was sub cultured and temperature, pH were
optimized at 7.4 and 37°C.
23. METHODOLOGY
Procedure for growth of bacteria
Before the growth of culture all the glassware was
sterilized. Take 1000ml of distilled water & add 24 gm of
nutrient broth in to it. Distribute the solution in 4 conical
flask (250ml each).Wrap the conical flask & the pipette
with newspaper. Keep all flasks & pipette in to the
autoclave for 1 hr. Turn off the autoclave after 1 hr& remove
the flask & pipette from it.
Take 250ml of tap water in conical flask & add 1 % of
cultured broth and 5% calcium lactate . The above flasks
were kept in rotary shaker for 24 hrs till the mixture turns
to turbid.(approx. 1 optical density at 600 nm wavelength).
Store the bacterial solution in incubator.
24. Introduction of bacteria in concrete:
• Bacteria will be introduced in the concrete while
mixing the concrete. The bacteria will be mixed in the
water which is used for mixing the concrete.
• The proportion of the bacteria is fixed and introduced
as per the proportion of water in concrete.
• The proportions of the bacteria are 105 cells and 106
cells i.e 24ml in 1 litre and 240ml in 1 litre.
25. Casting of self-healing concrete
• Casting of 36 cubes and 6 beams was done. The standard IS
moulds of size 15 × 15 ×15 cm and 15 x 15 x 70 cm were used
for casting. At the time of casting, the aggregates and
cement in required quantity were mixed. Then the required
amount of water was added to the mix.
• The mix is thoroughly mixed till uniform colour is
obtained. The mixing is done by machine. The surface of
block is levelled properly using a trowel. These blocks were
kept submerged in water for curing for 28 days after
casting.
26. Tests Carried Out On Bacterial Concrete:
• Compressive Test
• Flexural Test
• Scanning Electron Microscope Test (S.E.M.)
27. WORKING CHART
Collection of Bacillus Subtilis from Bhavans College,
Mumbai.
Cultivation of the Bacteria at Bhavans College, Andheri
for gaining more quantity of bacteria to work with.
Casting of cubes and beams were tested at 7, 14, 28, 56
days.
28. Following tests to be carried out after 7, 14, 28 days of curing
in the media
Compression Strength Test
S.E.MTest
Flexural Test
Result and analysis of bacterial concrete w.r.t the result of
normal concrete
Recommendation and Discussion for Future Study.
33. FUTURE CHALLENGES
The carbonation of structures in urban and coastal regions
of any country is generally very high. Carbonated concrete
looses protective power of steel. Therefore it accelerates
steel corrosion and related problems.
Hence, the efficiency of calcite deposition in resisting
carbonation and reduction in permeability to improve the
corrosion resistance must be studied in detail.
The temperatures, humidity, type of concrete, control of
various parameters such as type of mix, hence a
consolidated recommendation of any one’s result cannot
be arrived.
Apart from these, survival of microorganisms isolated
under different environmental conditions also needs to be
considered.
34. CONCLUSION
As per the above studied journals I can hereby conclude
that microbial precipitation help in making the concrete
which was having high chloride permeability to concrete
with moderate and low chloride permeability.
Also, corrosion current was less in case of samples from
microbial media as compared to control sample.
As the cell concentration increases the percentage mass
loss for steel reinforcement reduces.
Micrological remediation of crack is more efficient in
shallow cracks than deeper cracks.
Microbial concrete technology has proved to be better than
many conventional technologies because of its eco-
friendly nature, self-healing abilities and increase in
durability of various building materials.
35. REFERENCES
Bacterial Concrete: New Era For Construction Industry, International Journal
of Engineering Trends and Technology (IJETT) – Volume 4 Issue 9- Sep 2013
by Mayur Shantilal Vekariya, Prof. Jayeshkumar Pitroda.
Bacteria-based self-healing concrete, Delft University of Technology, Faculty of
Civil Engineering and Geosciences, Department of Materials and Environment
– Micro lab, Delft, the Netherlands, by Henk Jonkers.
Studies on Permeability of Self-Healing Built-In Bacteria Concrete,
International Journal of Recent Technology and Engineering (IJRTE) ISSN:
2277-3878, Volume-1, Issue-6, January 2013, Srinivasa Reddy V, Jyothi Kumar K
S, Seshagiri Rao MV, Sasikala Ch.
Self Healing Bacterial Concrete, IJRET: International Journal of Research in
Engineering and Technology eISSN: 2319-1163 | pISSN: 2321-7308,
Ravindranatha, N. Kannan, Likhit M. L.
Studies on Bacterial Concrete Exposed to Elevated Temperatures and Thermal
Cycles, Srinivasa Reddy, Seshagiri Rao, Sreenivasa Rao, Rahul K, IRACST –
Engineering Science and Technology: An International Journal (ESTIJ), ISSN:
2250-3498, Vol.3, No.1, February 2013.
“Permeability of Concrete”, ACI SP-108, D. Whiting and A. Walitt, ed., Detroit,
Michigan, pp.145-158. 1988.
