1. BIO-CONCRETE Prabhat kumar sahu 0901109200 Civil engg
SELF HEALING CONCRETE
BIO-CONCRETE
Prabhat kumar sahu
Civil engg

2. INTRODUCTION
Concrete is the most widely used material for construction.
It has low tensile strength than compressive strength.
So 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. Bacillus subtilis(JC3)
JC3 is a gram +ve bacteria
Can be cultivated easily in lab with minimum cost
It is non- pathogenic

5. EXPERIMENTAL PROGRAMME
Objectives
Experimental procedure
Chemical reactions
Experimental results

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

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

10. Surface 1 :Concrete surface Surface 2 : CaCO3 ptt

11. PLAIN CONCRETE BACTERIAL CONCRETE

12. Experimental results 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. Compressive strength (28 days)
Grade of concrete
Controlled concrete
(Mpa)
Bacterial concrete
% 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. Spliting tensile strength
No of days
Controlled concrete
(Mpa)
Bacterial concrete
%increase 7
3.78
4.30
13.75 14
4.62
5.28
14.28 28
4.85
5.74
18.35

15. Prctical use
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. CONCLUSION
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.

18. Referrence
Wang, J., Van Tittelboom, K., De Belie N., and Verstraete, W.. "Use of Silica Gel or Polyurethane
Immobilized Bacteria for Self-healing Concrete." Construction and Building Materials 26.1 (2012): Print.
Li, V., University of Michigan, “Self-healing concrete for safer, more durable infrastructure.” Science Daily,22 Apr Web. 28 Feb
Jonkers, H. M., A. Thijssen, G. Muyzer, O. Copuroglu, and Schlangen, E. "Application of Bacteria as Selfhealing Agent for the Development of Sustainable Concrete." Elsevier. Elsevier B.V., 30 Dec Web. 25Feb

19. Brownell, Blaine. "Self-Healing Concrete
Brownell, Blaine. "Self-Healing Concrete." Architect, The AIA Magazine (2011): Print. O'Driscoll, Cath. "Bacteria Fill in the Gaps in Concrete." Chemistry & Industry (2010). Web. 11 Feb
Zwaag, S. Van Der, and Schmets A. J. Self Healing Materials: An Alternative Approach to 20 Centuries of Materials Science. Dordrecht, The Netherlands: Springer, 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, Print