For making it economical, a part of the cement by weight is replaced with a material called ‘fly ash’ which is cheaper in cost and abundantly available. On the other hand the cracks in concrete lead to leakage problems and there is a need to address these problems for future. In the above context, the objective of the present investigation is to obtain the performance of the concrete by adding microbiologically induced special growth/filler and part of cement replaced by fly ash. One such thought leads to the development of very special concrete known as bacterial concrete where bacteria is induced in the concrete and part of the cement replaced by fly ash. A technique is adopted in the formation of concrete by utilizing microbiologically induced calcite (CaCo3) precipitation. Microbiologically induced calcite precipitation (MICP) is a technique that comes under a broader category of science called Bio-Mineralization. ‘Bacillus Subtilis’, a common soil bacterium can induce the precipitation of calcite.

1. 169
International Journal of Research and Innovation (IJRI)
International Journal of Research and Innovation (IJRI)
INVESTIGATION ON MECHANICAL PROPERTIES OF BACTERIAL CONCRETE
WITH FLYASH PARTIAL REPLACEMENT
Vummenthala Anusha1
, K. Mythili2
, Venkata Ratnam3
.
1 Research Scholar, Department of Civil Engineering, Aurora's Scientific Technological and Research Academy, Hyderabad, India.
2 Assistant professor , Department of Civil Engineering, Aurora's Scientific Technological and Research Academy, Hyderabad, India.
3 Associate professor , Department of Civil Engineering, Aurora's Scientific Technological and Research Academy, Hyderabad, India.
*Corresponding Author:
Vummenthala Anusha,
Research Scholar, Department of Civil Engineering,
Aurora Scientific Technological and Research Academy,
Hyderabad India.
Published: July 25, 2015
Review Type: peer reviewed
Volume: II, Issue : II
Citation: Vummenthala Anusha, Research Scholar (2015)
"INVESTIGATION ON MECHANICAL PROPERTIES OF BACTE-
RIAL CONCRETE WITH FLYASH PARTIAL REPLACEMENT "
INTRODUCTION
General
The most useful construction material adopted nowadays
to the tune of development of infrastructure to the con-
tinuously growing population in the world wide and their
requirement for the shelter of the population is the ce-
ment concrete.
The use of concrete is increasing worldwide in a fast track
and therefore the development of sustainable concrete is
anticipated for environmental reasons and also for the
improved strength parameters. As presently about 7%
of the total anthropogenic atmospheric CO2
emission is
due to cement production. If a mechanism is developed
that would contribute to a longer service life of concrete
structures and make the material not only more durable
but also more sustainable. One such mechanism that is
anticipated in recent years is the ability for self-repair,
i.e. the autonomous healing of cracks in concrete. Bacte-
rial concrete or self healing concrete would be the correct
solution for the construction activities for the durability
and strength of structures. If such mixture is combined
with a material called ‘fly ash’ the material shall become
economical thus saving significant cost.
Fly ash is a finely divided residue resulting from the com-
bustion of ground or powdered bituminous coal or sub-bi-
tumiNo.us coal (lignite) and transported by the flue gases
of boilers fired by pulverized coal or lignite. It is available
in large quantities in the country as a waste product from
a number of thermal power stations and industrial plants
using pulverized coal or lignite as fuel for the boilers. The
effective use of fly ash as a pozzolana in the manufac-
ture of cement and for part replacement of cement, as an
admixture in cement mortar with fly ash and concrete
with fly ash and in lime pozzolana mixture, has been es-
tablished in the country in recent years. Recent inves-
tigations on Indian fly ash have indicated greater scope
for their utilization as a construction material. Greater
utilization of fly ash will lead to not only saving of scarce
construction materials but also assist in solving the prob-
lem of disposal of this waste product from thermal power
stations. The recent investigations have also indicated the
necessity to provide proper collection methods for fly ash
so as to yield fly ash of quality and uniformity which are
Abstract
For making it economical, a part of the cement by weight is replaced with a material called ‘fly ash’ which is cheaper in
cost and abundantly available. On the other hand the cracks in concrete lead to leakage problems and there is a need
to address these problems for future.
In the above context, the objective of the present investigation is to obtain the performance of the concrete by adding
microbiologically induced special growth/filler and part of cement replaced by fly ash. One such thought leads to the
development of very special concrete known as bacterial concrete where bacteria is induced in the concrete and part
of the cement replaced by fly ash. A technique is adopted in the formation of concrete by utilizing microbiologically
induced calcite (CaCo3
) precipitation. Microbiologically induced calcite precipitation (MICP) is a technique that comes
under a broader category of science called Bio-Mineralization. ‘Bacillus Subtilis’, a common soil bacterium can induce
the precipitation of calcite.
For the experimental investigation firstly cement mortar blocks are casted using fly ash as partial replacement of ce-
ment without bacteria and also with a common soil bacterium called ‘Bacillus Subtilis’ of different concentrations like
104
, 105
, 106
, 107
and 108
cells/ml. The cement mortar blocks are tested for 7 days and 28 days strength. Finally it is
observed that the mortar blocks made with 105
cells/ml. concentration of ‘Bacillus Subtilis’ attained good strength when
compared with normal mortar blocks.
Therefore, for further experimental investigations ‘Bacillus Subtilis’ culture samples with 105
cells/ml.
From the experimental investigations it is observed that the compressive strength, flexural strength and split tensile
strength are on par with the normal concrete strength parameters. The three strength parameters of bacterial concrete
are found to be higher than that of the normal concrete.
1401-1402

2. 170
International Journal of Research and Innovation (IJRI)
prime requirements of fly ash for use as a construction
material. This standard has been prepared to give general
guidance towards the suitability of fly ash as a pozzolana
and as an admixture for structural mortar and concrete.
Humans have the ability to precipitate minerals in the
form of bones and teeth continuously. This ability is not
only confined to human beings, even ‘Bacillus Subtilis’, a
common soil bacterium, can continuously precipitate cal-
cite. The bacterial concrete with fly ash makes use of cal-
cite precipitation by bacteria. The phenomenon is called
microbiologically induced calcite precipitation (MICP).
The MICP is a technique that comes under a broader cat-
egory of science called bio-mineralization. It is a process
by which living organism or bacteria form inorganic sol-
ids. ‘Bacillus Subtilis’, when used in concrete with fly ash,
can continuously precipitate a new highly impermeable
calcite layer over the surface of the already existing con-
crete layer. The precipitated calcite has a coarse crystal-
line structure that readily adheres to the concrete with fly
ash surface in the form of scales. In addition to the ability
to continuously grow upon itself, it is highly insoluble in
water.
It resists the penetration of harmful agents like chlorides,
sulphates, and carbon dioxide into the concrete with fly
ash thereby decreasing the deleterious effects they cause.
Due to its inherent ability to precipitate continuously,
bacterial concrete with fly ash can be called as a ‘smart
bio-material’ for repairing concrete.
Bacterial Concrete using Fly Ash
Bacterial concrete using fly ash is a new concept in which
living organism or bacteria called ‘Bacillus Subtilis’ is
mixed in water with an ordinary Portland cement, fly ash
along with fine aggregate and coarse aggregate.
Concrete with fly ash as a structural material
The most widely used construction material is concrete,
commonly made by mixing Portland cement with fly ash,
sand, crushed rock and water. The present consumption
of concrete in the world is estimated to be around twen-
ty thousand million metric tons every year or more than
three metric tons for every living human being. The world
trends indicate that man consumes no other material ex-
cept water in such tremendous quantities.
EXPERIMENTAL PROGRAMME
General Methodology
The present investigation is aimed at arriving the perfor-
mance of the bacterial concrete in comparison with the
normal concrete using fly ash as partial replacement
of cement for M20 and M40 grade concrete, after thor-
oughly understanding the parameters influencing the
strength improvement which are designed with the help
of IS:10262-2009.
The experimental programme is divided into four phases.
Phase I: Laboratory setup and procurement of materials.
Phase II: Mixing of cement mortar, moulding and curing
of cement mortar specimens.
Phase III: Mixing of concrete with fly ash as partial re-
placement of cement, moulding and curing of concrete
specimens.
Phase IV: Testing procedure for evaluating the strength
parameters of cement mortar and concrete specimens.
Phase V: Evaluating test results.
Phase I
Phase I involves establishment of necessary laboratory set
up and procurement of required materials.
Laboratory set up
The Concrete Technology Laboratory at University College
of Engineering, Osmania University is used for this pro-
ject. Universal testing machine and compression testing
machine are used to test all the concrete specimens. The
curing of the concrete specimens is done by submerging
the specimens in storage tanks.
Procurement of materials
The materials used for the investigative study of bacterial
concrete using fly ash are given below.
• Cement
• Fly ash
• Fine aggregate
• Coarse aggregate
• Water
• Micro Organisms ‘Bacillus Subtilis’ a model laboratory
bacterium is used.
Plate 3.1 Colony morphology of ‘Bacillus Subtilis’ on agar plate
(Irregular, dry, white, opaque colonies)
Plate 3.2 Phase contrast micro photograph of ‘Bacillus Subtilis’
(Long rods, 0.6-0.8µm in width and 2.0-3.0 µm in length, gram
positive)
Plate 3.3 Microscopic photograph of multiple ‘Bacillus Subtilis’
cultured at Microbiology Department, Osmania University, Hy-
derabad (View 1)

3. 171
International Journal of Research and Innovation (IJRI)
Plate 3.4 Microscopic photograph of multiple ‘Bacillus Subtilis’
cultured at Microbiology Department, Osmania University, Hy-
derabad (View 2)
Plate 3.5 Microscopic photograph showing the culture of ‘Bacil-
lus Subtilis’ cultivated at Microbiology Department, Osmania
University, Hyderabad (View 1)
Plate 3.6 Microscopic photograph showing the culture of ‘Bacil-
lus Subtilis’ cultivated at Microbiology Department, Osmania
University, Hyderabad (View 2)
Liquid form of bacteria ‘Bacillus Subtilis
Phase II
Mixing of cement mortar
The following mix cases are considered for both normal
cement mortar and bacterial cement mortar using fly
ash as partial replacement of cement. The mix propor-
tion adopted is 1: 3.
Case 1 : Normal or control cement mortar mix with fly
ash.
Case 2 : Cement mortar mix with fly ash with 104
cells/
ml. bacterial solution.
Case 3 : Cement mortar mix with fly ash with 105
cells/
ml. bacterial solution.
Case 4 : Cement mortar mix with fly ash with 106
cells/
ml. bacterial solution.
Case 5 : Cement mortar mix with fly ash with 107
cells/
ml. bacterial solution.
Case 6 : Cement mortar mix with fly ash with 108
cells/
ml. bacterial solution.
Phase III
Mixing of concrete with fly ash
Two mixes of M20 and M40 grades of concrete are con-
sidered for both normal concrete and bacterial concrete
using fly ash as partial replacement of cement of 10%,
20% and 30%. The mix design is adopted as per IS:
10262-2009 and mixes are as follows.
• Normal mix of concrete with fly ash for M20 and M40
grade as per IS: 10262-2009.
• Bacterial mix of same concrete using 105
cells/ml of
‘Bacillus Subtilis’ culture for M20 and M40 grade as per
IS: 10262-2009.
Slump of concrete being measured in Laboratory
Compaction factor of concrete being measured in the Laboratory

4. 172
International Journal of Research and Innovation (IJRI)
Variation of slump for M20 grade concrete
Variation of compaction factor for M20 grade concrete
From the Figures it can be ascertained that as the fly
ash replacement increases, the slump and compaction
factors increases gradually for M20 concrete.
shows the variation of slump and compaction factors
for M40 grade concrete and the same is depicted in the
graphs 3.6 and 3.7 respectively.
Workability of M40 concrete (slump and compaction
factors)
% fly ash
replace-
ment
Water
cement
ratio
Super
plasti-
cizer
Slump in mm Compaction factor
in mm
Without
bacteria
With
bacteria
Without
bacteria
With
bacteria
10 0.35 0.8 91 90 0.895 0.910
20 0.35 0.8 102 100 0.905 0.915
30 0.35 0.8 104 102 0.915 0.920
Variation of slump for M40 grade concrete
Variation of compaction factor for M40 grade concrete
From the Figures it can be ascertained that as
the fly ash replacement increases, the slump and
compaction factors increases gradually for M40
concrete also.
Thirty six cubes, 36 cylinders and 36 prisms are
casted as shown in Figure and as explained earlier
and are subjected to curing. After each period of
curing, the cube, cylinder and prism specimens are
tested and the results recorded as per given in the
following sections.
Moulds of cement concrete cubes being casted in the Laboratory
Phase IV
Phase IV deals with the testing procedures for evaluating
the strength parameters of cement mortar specimens us-
ing fly ash and concrete specimens with fly ash with and
without bacteria.
Testing procedure
The concrete specimens considered in this investigation
programme are subjected to the following tests.
Compression test
Compression test is conducted confirming to IS 516-
1959, on the concrete specimens, on the Universal
Testing Machine (200 MT). In this test, cube is placed
with the cast faces not in contact with the platens of
testing machine i.e., the position of the cube when tested
is at right angles to that as cast. Load is applied at a
constant rate of stress equal to 15 MPa/min according
to relevant IS code and the load at which the specimen
failed is recorded. Thus the compressive strengths of the
specimens are obtained and the results of all samples
are presented in nest chapter. The compression test-
ing machine at the University College of Engineering is
shown in Figure.
Compression testing at concrete Laboratory at UCE, OU

5. 173
International Journal of Research and Innovation (IJRI)
Summary
The total experimental programme which includes five
phases, viz. laboratory set up and procurement of mate-
rials, evaluation of physical properties of materials, mix-
ing of cement mortar and cement concrete using fly ash
as partial replacement for cement, moulding and curing
of test specimens and testing procedure for evaluating
strength parameters of test specimens are explained in
this chapter.
ANALYSIS OF TEST RESULTS AND OBSERVATIONS
Strength Characteristics
Preliminary remarks
This chapter deals with the analysis of experimental
tests conducted on hardened mortar specimens and
concrete specimens which are casted using fly ash,
after attaining the desired age of curing with respect to
its compressive strength, flexural strength split tensile
strength and pulse velocity. The results are precisely
and systematically compiled and presented. They are
also represented in graphs for its critical analysis and
interpretations.
Properties of Cement Mortar using Fly Ash
Compressive strength
The most common of all the parameters is the compres-
sive strength of cement mortar because it is a desirable
characteristic of concrete. The compressive strength of
cement mortar is quantitatively related to the compres-
sive strength of concrete.
7 days compressive strength
Case 1: Normal or control cement mortar with fly ash:
The specimens with submerged curing have achieved an
average compressive strength of 26.3 MPa.
Case 2: Cement mortar with fly ash with 104
cells/ml
of bacterial solution: These specimens have attained
an average compressive strength of 28.8 MPa. after the
submergedcuring.
Case 3: Cement mortar with fly ash mix added with
105
cells/ml bacterial solution: The specimens with the
submerged curing have attained an average compressive
strength of 31.6 MPa.
Case 4: Cement mortar with fly ash mix added with 106
cells/ml bacterial solution: The specimens have attained
an average compressive strength of 29.3 MPa. after the
submerged curing.
Case 5: Cement mortar with fly ash mix added with 107
cells/ml bacterial solutions: The specimens with the
submerged curing have attained an average compressive
strength of 27.6 MPa.
Case 6: Cement mortar with fly ash mix added with 108
cells/ml bacterial solutions: The specimens have at-
tained an average compressive strength of 26.9 MPa.
when subjected to sub-merged curing.
28 days compressive strength
Case 1: Normal or control cement mortar with fly ash
mix case: The specimens subjected to submerged curing
have achieved an average compressive strength of 30.7
MPa.
Case 2: Cement mortar with fly ash mix added with
104
cells/ml bacterial solutions: These specimens have
attained an average compressive strength of 32.7 MPa
after the submerged curing.
Case 3: Cement mortar with fly ash mix added with 105
cells/ml bacterial solution: The specimens with the
submerged curing have attained an average compressive
strength of 37.2 MPa.
Case 4: Cement mortar with fly ash mix added with 106
cells/ml bacterial solution: An average compressive
strength of 33.5 MPa is obtained from the test specimens
after the submerged curing.
Case 5: Cement mortar with fly ash mix added with 107
cells/ml bacterial solutions: The specimens with the
submerged curing have attained an average compressive
strength of 32.5 MPa.
Case 6: Cement mortar with fly ash mix added with 108
cells/ml bacterial solutions: The specimens have at-
tained an average compressive strength of 31.7 MPa
when they are subjected to submerged curing.
From the above results it can be seen that the 28 days
compressive strength is maximum for the concentration
of 105
cells/ml of bacterial solution, hence the same con-
centration of bacterial solution is adopted for concrete
specimens.
Properties of Concrete with Fly Ash and Bacteria
Compressive strength
The most important and useful of all the parameters is
the compressive strength, because most of the param-
eters are quantitatively related to compressive strength.
7 days compressive strength
The average 7 days compressive strengths of concrete
with fly ash as partial replacement of cement for M20
and M40 grades of concrete with and without bacte-
ria and are tabulated in Table 4.1 and also presented
graphical in Figure
28 days compressive strength
The average 28 days compressive strengths of concrete
with fly ash as partial replacement of cement for vari-
ous grades and proportions is tabulated as below (with
and without bacteria) are tabulated in Table 4.1 and also
presented graphically in Figures.

6. 174
International Journal of Research and Innovation (IJRI)
Compressive strength of M20 and M40 concrete at 7
and 28 days (in MPa)
Con-
crete
grade
% fly
ash
replace-
ment
Without bacteria With bacteria % increase in
strength of bacte-
rial fly ash concrete
than normal fly ash
concrete
7 days 28 days 7 days 28 days 7 days 28 days
M20 10 16.41 26.90 17.55 30.10 6.95 11.90
20 12.90 19.20 13.75 21.45 6.59 11.72
30 10.34 17.82 11.08 20.01 7.16 12.29
M40 10 29.45 48.30 31.85 52.85 8.15 9.42
20 21.84 36.40 23.35 40.40 6.91 10.99
30 18.90 31.50 20.12 33.80 6.46 7.30
Compressive strength of M20 concrete at 7 days
Compressive strength of M40 concrete at 7 days
Compressive strength of M20 concrete at 28 days
Compressive strength of M40 concrete at 28 days
Flexural tensile strength of M20 concrete at 7 days
Flexural tensile strength of M40 concrete at 7 days
Flexural tensile strength of M20 concrete at 28 days
Flexural tensile strength of M40 concrete at 28 day
Split tensile strength of M20 concrete at 7 days
Split tensile strength of M40 concrete at 7 days

7. 175
International Journal of Research and Innovation (IJRI)
Split tensile strength of M20 concrete at 28 days
Split tensile strength of M40 concrete at 28 days
Ultrasonic Pulse Velocity Tests
Pulse velocity tests
28 days pulse velocity test
(a) Normal or control concrete using fly ash for various
proportions of mix with M20 grade is as follows:
The cube specimens subjected to submerged curing with
10% fly ash have attained an average pulse velocity of
4390m/sec (Good).
The cube specimens subjected to submerged curing with
20% fly ash have attained an average pulse velocity of
4260m/sec (Good).
The cube specimens subjected to submerged curing with
30% fly ash have attained an average pulse velocity of
4100m/sec (Good).
(b) Bacterial concrete using fly ash as partial replace-
ment in various proportions of mix with M20 grade:
The cube specimens subjected to submerged curing with
10% of fly ash have attained an average pulse velocity of
4410/sec (Good).
The cube specimens subjected to submerged curing with
20% fly ash have attained an average pulse velocity of
4350m/sec (Good).
The cube specimens subjected to submerged curing with
30% fly ash have attained an average pulse velocity of
4230m/sec (Good).
(c) Normal or control concrete using fly ash in various
proportions mix with M40 grade:
The cube specimens subjected to submerged curing with
10% fly ash have attained an average pulse velocity of
4490m/sec (Good).
The cube specimens subjected to submerged curing with
20% fly ash have attained an average pulse velocity of
4380m/sec (Good).
The cube specimens subjected to submerged curing with
30% fly ash have attained an average pulse velocity of
4310m/sec (Good).
(d) Bacterial concrete with fly ash mix with M40 Grade:
The cube specimens subjected to submerged curing with
10% fly ash have attained an average pulse velocity of
4550m/sec (Good).
The cube specimens subjected to submerged curing with
20% fly ash have attained an average pulse velocity of
4470m/sec (Good).
The cube specimens subjected to submerged curing with
30% fly ash have attained an average pulse velocity of
4410m/sec (Good).
Discussions and conclusion
Scanning Electron Microscope (SEM) Investigation
To reveal the details of hydrated cement samples, scan-
ning electron microscope technique is required. SEM
technique is utilized for taking the photographs to find
out the presence of ‘Bacillus Subtilis’ bacteria in the
concrete samples and also to know about the hydrated
structure of normal and bacterial concretes.
A small piece of M20 grade concrete with fly ash and
two pieces of M20 grade and one piece of M40 grade
bacterial concrete are collected from standard hardened
cubes and they are sent to the RUSKA Labs, College of
Veterinary Sciences, S.V Veterinary University, Rajendra
Nagar, Hyderabad to obtain the SEM photographs of
normal and bacterial concrete samples.
One SEM photograph of normal concrete (with fly ash)
sample, with X300 magnification shows no evidence
of presence of bacteria and calcite formation. Similarly
three SEM photographs of bacterial concrete (with fly
ash) samples (two with 9000 magnification and the other
with 9500 magnification) are obtained in which the pres-
ence of ‘Bacillus Subtilis’ bacteria is clearly visible. The
average length of ‘Bacillus Subtilis’ bacteria observed is
around 2.00 µm. The SEM photograph of normal con-
crete with X300 magnification and bacterial concrete
(with fly ash) with 9000 and 9500 magnifications are
depicted .
A SEM photograph of non-bacterial concrete with 10% fly ash
for M40 grade in X300 magnification
A SEM photograph of bacterial concrete with 10% fly ash for
M20 grade with 9000 magnification.

8. 176
International Journal of Research and Innovation (IJRI)
A SEM photograph of bacterial concrete with 20% fly ash for
M20 grade with9500 magnification
A SEM photograph of bacterial concrete with 10% fly ash for
M40 grade with 9000 magnification
Conclusions
Based on the present experimental investigations, the following
conclusions are drawn.
• ‘Bacillus Subtilis’ can be produced from laboratory which is
proved to be a safe and cost effective.
• The addition of ‘Bacillus Subtilis’ bacteria improve the hy-
drated structure of cement mortar.
• The compressive strength of cement mortar using fly ash is
maximum with the addition of ‘Bacillus Subtilis’ bacteria for a
cell concentration of 105 cells/ml of mixing water. Therefore,
bacteria with a cell concentration of 105
cells/ml of mixing wa-
ter are used in the present investigations.
• The addition of ‘Bacillus Subtilis’ and fly ash do not affect
the workability aspects of concrete and there is no change in
the workability aspects of bacterial concrete when compared to
normal concrete without bacteria.
• The addition of ‘Bacillus Subtilis’ increases the compressive
strength without bacteria for M20 and M40 grade concrete with
fly ash, the compressive strength increases up to 7.5% for M20
and 8.00% for M40 grade at 28 days age.
Limitations of the Bacterial Concrete
However this study of bacterial concrete has the following limi-
tations.
1. The procurement and maintenance of stock culture is tedious
and time consuming.
It may also presume that the bacterial concrete is also having
the following limitations.
1 The bacterial concrete has less resistance to the chemical at-
tacks.
2. The bacterial concrete offers less resistance the fire acci-
dents.
REFERENCES:
1. Chiara Barabesi, Alessandro Galizzi, Giorgio Mastromei, Mila
Rossi, Elena, Tamburini and Brunella Perito Pavia, Italy, Micro
Organisms-’Bacillus Subtilis’ 2007.
2. Leuschner, G.Renata, Lillford, J.Peter―Effect of hydration on
molecular mobility in phase-bright Bacillus subtilis spores
Journal of microbiology, 2000.
3. Massimiliano Marvasi, T.Pieter, Visscher, Brunella Perito,
Giorgio Mastromei and Lilliam Casillas-Martinew―Physiologi-
cal requirements for carbonate precipitation during biofilm
development of Bacilus Subtilis etfa mutant Journal FEMS
Microbiology Ecology 2009.
4. J.L.Day, S.S.Bang and V.Ramakrishnan―Microbiologically
induced sealant for concrete crack remediation 2003.
5. V.Ramakrishnan, S.S.Bang, and R.K.Panchalan, ‘Bacterial
Concrete–A self-repairing biomaterial,’ Proceedings of the 10th
International Congress on polymers in concrete and ICPI/ICRI
International concrete repair workshop, Honolulu, HI, 2001.
6. Willem De Muynck, Kathelijn Cox, Nele De Belie, Willy Ver-
straete―Bacterial carbonate precipitation as an alternative
surface treatment for concrete 2003.
7. H.S. Patil, D.B. Raijiwala, Hingwe Prashant and Bhabhor Vi-
jay―Bacterial concrete - A self healing concrete, International
Journal of Applied Engineering Research, Vol. 3, No. 12, 2008,
pp. 1719–1725.
8. Ke-Ru-Wu, Bing Chen, Wu Yao, Dong Zhang―Effect of
coarse aggregate tupe on mechanical properties of HPC. cement
and concrete research, 2001, Vol. 31, pp. 1421-1425.
9. P.Ghosh, S.Mandal, B.D.Chattopadhyay and S.Pal―Use of
Microorganisms to improve the strength of cement-sand mor-
tar 2004.
10. C.Raj Kumar―Provisions for cements and mineral admix-
ture, ICJ 2001, pp.105-112.
11. Edvardsen, C.K Water permeability and self-healing of
through cracks in concrete (fly ash), Deutscher Ausschuss fur
Stahlbeton, Heft 455, 1996 (in German).
12. Reinhardt, H-W. and Joos, M.Permeability and self-healing
of cracked concrete (fly ash) as a function of temperature and
crack width, C and CR 33, 2003, pp. 981-985.
Author
Vummenthala Anusha
Research Scholar,
Department of Civil Engineering,
Aurora's Scientific Technological and Research Academy,
Bandlaguda,Hyderbad - 500005, India.
Mythili Rao
Assistant Professor,
Department of Civil Engineering,
Aurora's Scientific Technological and Research Academy,
Hyderabad India.
Venkata Ratnam,
Associate professor,
Department of Civil Engineering,
Aurora's Scientific Technological and Research Academy,
Hyderabad India.