The document discusses the use of Bacillus subtilis (JC3) bacteria to induce self-healing properties in concrete. The bacteria are added to concrete mixtures along with calcium lactate as a nutrient. When cracks form in the concrete, the bacteria germinate from bacterial spores in the cracks, consume the calcium lactate, and precipitate calcium carbonate to fill the cracks. Experimental results showed increased compressive strength, splitting tensile strength, and reduced water permeability in bacterial concrete compared to normal concrete. The degree of improvement increased with higher bacterial concentrations up to 10^5 cells/ml of water. Self-healing concrete has potential benefits of reduced maintenance costs.

1. BIO-CONCRETE
AMIT KUMAR
611441521072
Civil Engg

2.  Concrete is the most widely used material for
construction.
 It has low tensile strength than compressive strength.
 So It is most effective when reinforced by steel bars.
 Concrete is a brittle material with low tolerance for
strain.

3.  So it forms cracks, leading to
 corrosion
 water ingress
 Decrease in durability
 increasing maintenance cost
 self healing concrete is a solution to all above.
 Here we will induce self healing property using JC3
(Bacillus Subtilis) bacteria.

4.  JC3 is a gram +ve
bacteria
 Can be cultivated
easily in lab with
minimum cost
 It is non-
pathogenic
Bacillus
subtilis(JC3)

5.  Objectives
 Experimental procedure
 Chemical reactions
 Experimental results

6.  Analysis of compressive strength with varying
bacterial concentration.
 Analysis of split tensile strength .
 Effect of bacterial conc. on different grades of concrete

7.  JC3 bacteria is added to concrete with Calcium lactate
as feeding material.
 The conc. of JC3 bacteria is proportional to H2O conc.
 Calcium lactate & JC3 mixture is added in form of
palates .
 Initially JC3 bacteria spores remain in dormant state
 These spores germinate when come in contact with
H2O in temp around 25deg.

8.  When cracks are formed ,the local palates also breaks
releasing JC3
 Water also seeps through cracks
 Bacterial spores germinates when comes in contact
with H2O
 JC3 feeds on Calcium lactate forming CaCO3 which
precipitates on cracks.
 This process is known as Microbiologically Induced
Calcium Carbonate precipitation(MICCP)

9.  MICCP involves a complicated chain of reaction.
 But can sum up to following two steps
 Ca2+ + Cell → Cell-Ca2+
 Cell-Ca2+ + CO32- → Cell-CaCO3↓

12. Cell Conc./ml of
water
Compressive
strength
(28 days)(Mpa)
% increase
NIL 51.81 _
10^4 58.02 11.99
10^5 61.79 16.15
10^6 57.21 10.42
10^7 54.66 5.51

13. Grade of
concrete
Controlled
concrete
(Mpa)
Bacterial
concrete
(Mpa)
% increase
M 20 28.18 32.74 16.18
M 40 51.19 60.17 17.54
M 60 72.61 94.21 29.75
M 80 93.8 119.2 27.08

14. No of days Controlled
concrete
(Mpa)
Bacterial
concrete
(Mpa)
%increase
7 3.78 4.30 13.75
14 4.62 5.28 14.28
28 4.85 5.74 18.35

15.  The use of Self healing concrete has been very
limited world wide .
 The concept is still in developing stage & on the way to
large scale use.
 In India no use of this has been done.
 A group of professors in JNTU are researching on
bacterial concrete.

16. Based on the present experimental investigations, the
following conclusions are drawn:
 decrease of permeability of water and other liquids in
concrete.
 increases the compressive strength of concrete. The
compressive strength
 Splitting tensile strength is increased
 All over maintenance cost is minimized

17.  From all above results we can consider non pathogenic
bacteria as a major material for inducing self healing
property in concrete.
 Now self healing concrete can be said to be future
material.

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40.Print.
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Schlangen, E. "Application of Bacteria as Selfhealing Agent
for the Development of Sustainable Concrete." Elsevier.
Elsevier B.V., 30 Dec. 2008. Web. 25Feb. 2012.

19.  Brownell, Blaine. "Self-Healing Concrete." Architect, The
AIA Magazine (2011): 90-91. Print. O'Driscoll, Cath.
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Industry (2010). Web. 11 Feb. 2012.
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Materials: An Alternative Approach to 20 Centuries of
Materials Science. Dordrecht, The Netherlands: Springer,
2007. Print.
 Yonkers, H. M., and E. Schlangen. "Crack Repair by
Concrete-immobilized Bacteria." Proc. of First
International Conference on Self Healing Materials, Delft
University of Technology, Noordwijk Aan Zee. Springer,
2007. Print