2. CONTENTS
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• Introduction
• Bio Concrete
• Constituents Of Bio Concrete
• Mechanism
• Application Of Healing Agent
• Evaluation
• Conclusion
• References
3. INTRODUCTION
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• Cracking in concrete is a main concern throughout the
because it cause loss of strength of structure with Time.
• A environmental friendly solution is preferred i.e. biological
concrete over other alternatives like epoxy resins which is non
degradable.
• The bacteria based concrete is believed to remain hibernated
within the concrete for up to 200 years. When cracks appear
in a concrete structure and water starts to seep in through, the
spores of the bacteria starts microbial activities on contact
with the water and oxygen.
4. BIO CONCRETE
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• Its specially made to increase the lifespan or the
durability of concrete structure by the self healing
action of that concrete.
• Bio concrete is also called as BACTERIAL
CONCRETE or SELF HEALING CONCRETE.
• Its is a special type of concrete invented by a group of
microbiology researchers under the head of Henk
Jonkers.
5. Constituents Of Bio Concrete
Mainly there are two components present in bio concrete :
• The special bacteria that has to resist the alkalinity and the
mechanical stress of concrete.
• The chemical precursor to activate the bacteria.
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7. MECHANISM
• The cracks are formed on the surface of concrete due to
many reasons like shrinkage, Inadequate water for
hydration.
• But if cracks are more than .2mm then concrete itself fail
to heal itself thus opening passage to chemicals and other
corroding materials.
• In bio-concrete if water is in contact with the concrete
though the cracks the bacteria get activated from its stage
of dormancy and through its metabolic activities forms
calcite which further acts as a healing material .7
8. Continued..
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• The water is deliberately forced into the crack
and the precursor is activated.
• The activated precursor intern induces the
bacteria to react with that precursor and form a
base of calcium carbonate called as limestone.
• When the cracks are filled completely by the
bacteria it again goes to the stage of dormancy.
• Again if in future if cracks get widen and the
foreign particles tends to enter the cracks the
bacteria get activated and thus heal the cracks.
Thus acting as a long lasting healing agent.
9. What is happening inside bio concrete
(mechanism)
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• The cracks are formed on the surface of concrete
due to many reasons like shrinkage, Inadequate
water for hydration …etc.
• The water is deliberately forced into the crack
and the precursor is activated
10. Continued…
• The activated precursor intern induces the
bacteria to react with that precursor and form a
base of calcium carbonate called as limestone
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13. Application Of Healing Agents
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BY DIRECT APPLICATION
• The bacteria and the chemical precursor(calcium lactate) are added
directly while making the concrete.
ENCAPSULATION (Light Weight Aggregate)
• The part of the coarse aggregate is replaced by the light weight
aggregate (LWA) , which is saturated with twice the calcium lactate
solution and spores of the bacteria.
• After saturation of the clay particles with 6% healing agents and
then concrete is made.
14. Healing Agents
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The bacteria which are used as the healing
agents are :
• Acidithio bacillus sp.
• Mycobacterium sp.
• Proteobacteria
• Acidobacteria
• Actinobacteria
19. APPLICATION
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• From enhancement in durability of cementitius materials to
improvement in sand properties, from repair of limestone
monuments, sealing of concrete cracks to highly durable
bricks, microbial concrete has been successful in one and all.
• This new technology can provide ways for low cost and
durable roads.
• High strength buildings with more bearing capacity.
• Long lasting river bank.
• Low cost durable housing.
20. CONCLUSION
• 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.
• Enhancement of compressive strength, reduction in
permeability, water absorption, reinforced corrosion have
been seen in various cementitious and stone materials.
• Cementation by this method is very easy and convenient for
usage. This will soon provide the basis for high quality
structures that will be cost effective and environmentally
safe but, more work is required to improve the feasibility of
this technology from both an economical and practical
viewpoints.
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21. REFERENCES
• International Journal of Materials Chemistry and Physics
Vol. 1, No. 1, 2015, pp. 11-19.
•Samudre MP, Mangulkar MN, Saptarshi SD, A review of
emerging way to enhance the durability and strength of
concrete structures: Microbial concrete, Intern J Innov Res Sci
Eng Tech. 3 (2014) 9311-9316.
• Google, google images, engineering trends.
• Ivanchev I, Research on cracks in reinforced concrete
elements by taking into account the experimentally
determined concrete and reinforcing steel mechanical
properties, Ind JApp Res 5 (2015) 239-241.
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