AMB Express,
Journal Year:
2025,
Volume and Issue:
15(1)
Published: April 28, 2025
The
technique
of
microbially
induced
calcium
carbonate
precipitation
(MICP)
has
a
bright
prospect
in
the
repair
concrete
structures
with
diseases,
so
evaluation
effect
and
its
influencing
factors
are
very
important
issues
for
civil
engineers.
In
this
paper,
multi-phase
mixed
precipitate
models
established
by
using
random
particle
generation
packing
algorithm.
Combined
cohesive
zone
model,
deformation
failure
behavior
notched
cement-mortar
microbeams
before
after
under
three-point
bending
loading
numerically
simulated.
recovery
rate
is
proposed
to
characterize
microbeam.
influences
proportion
crystalline
phases
precipitate,
size
notch
location
on
it
evaluated.
It
found
that
peak
load
microbeam
decreases
from
22.16
20.60%
as
calcite
increases
0
1
combination
case
vaterite
particles
precipitate.
However,
aragonite,
1,
35.01
20.77%.
For
only
grains
12.73
36.85%
when
2
3.4
μm.
When
distance
between
center
midspan
40
μm,
20.44
77.26%.
effects
phases,
repairing
can
be
explained
population
matrix-particle
interface
stress
concentration
degree
Considering
compositions
regulated
control
environmental
process
parameters,
research
paper
great
significance
engineering
application
MICP
technique.
The Science of The Total Environment,
Journal Year:
2024,
Volume and Issue:
947, P. 174553 - 174553
Published: July 6, 2024
The
self-healing
bioconcrete,
or
bioconcrete
as
concrete
containing
microorganisms
with
capacities,
presents
a
transformative
strategy
to
extend
the
service
life
of
structures.
This
technology
harnesses
biological
capabilities
specific
microorganisms,
such
bacteria
and
fungi,
which
are
integral
material's
capacity
autonomously
mend
cracks,
thereby
maintaining
structural
integrity.
review
highlights
complex
biochemical
pathways
these
organisms
utilize
produce
healing
compounds
like
calcium
carbonate,
how
environmental
parameters,
pH,
temperature,
oxygen,
moisture
critically
affect
repair
efficacy.
A
comprehensive
analysis
recently
published
peer-reviewed
literature,
contemporary
experimental
research
forms
backbone
this
focus
on
microbiological
aspects
process.
assesses
challenges
facing
including
longevity
microbial
spores
cost
implications
for
large-scale
implementation.
Further,
attention
is
given
potential
directions,
investigating
alternative
agents
optimizing
environment
support
activity.
culmination
investigation
call
action
integrating
in
construction
broader
scale,
realizing
its
fortify
infrastructure
resilience
sustainability.
Buildings,
Journal Year:
2024,
Volume and Issue:
14(12), P. 3782 - 3782
Published: Nov. 27, 2024
Microbially
induced
calcium
carbonate
precipitation
(MICP)
presents
a
sustainable,
environmentally
friendly
solution
for
repairing
cracks
in
cement-based
materials,
such
as
mortar
and
concrete.
This
self-healing
approach
mechanism
enables
the
matrix
to
autonomously
close
its
own
over
time.
In
this
study,
specimens
(50
mm
diameter
25
height)
were
exposed
submersion
wet–dry
cycle
environment.
The
considered
nutrient-rich
suspension
with
lactate,
urea,
nitrate,
Bacillus
subtilis
or
Sporosarcina
pasteurii
biomineralization
approach.
efficiency
was
assessed
through
optical
microscopy
combined
image
processing,
focusing
on
analysis
of
superficial
crack
closure
area.
S.
B.
exhibited
notable
capabilities
effectively
healing
cracks,
respectively,
8
mm2
5
at
35
days.
Healing
particularly
effective
samples
placed
submerged
environment,
especially
69
mM
concentration
lactate
bacterial
suspensions
containing
subtilis,
where
87.5%
4
closed
within
21
contrast,
free
ions
solution,
resulting
from
anhydrous
cement
hydration,
proved
ineffective
urea-rich
environments.
However,
addition
an
external
source
(calcium
nitrate)
significantly
enhanced
closure,
emphasizing
critical
role
availability
optimizing
MICP
bio-agents
materials.
These
findings
highlight
potential
advance
sustainable
concrete
technologies.
Buildings,
Journal Year:
2024,
Volume and Issue:
14(12), P. 3916 - 3916
Published: Dec. 7, 2024
Concrete
is
prone
to
cracking
over
time,
leading
the
deterioration
of
concrete
structures.
Using
biomineralization
capabilities
bacteria,
cracks
in
can
be
remediated
favorable
conditions.
In
this
study,
Bacillus
subtilis
spores
were
immobilized
three
different
healing
agents,
namely
lightweight
expanded
clay
aggregates
(LECAs),
polyvinyl
acetate
(PVA)
fibers,
and
an
air-entraining
admixture
(AEA).
spores,
with
a
turbidity
equivalent
4
McFarland
standard,
used
dosages,
0.01,
0.1,
1%
(by
weight)
cement.
Based
on
dosage,
groups
developed
each
group
consisted
total
nine
mixes,
which
differentiated
based
method
delivery
bacterial
spores.
The
specimens
pre-cracked
after
7
days,
using
embedded
steel
rod,
being
post-tensioned
universal
testing
machine.
self-healing
efficiency
was
evaluated
ultrasonic
pulse
velocity
surface
crack
analysis,
ImageJ
software,
precipitate
analyzed
microstructural
tests,
scanning
electron
microscopy,
X-ray
diffraction,
Fourier
transform
infrared
spectroscopy
analysis.
results
verified
that
improved
increase
dosage
curing
time.
LECAs
proved
promising
carrier,
by
accommodating
nutrient
media
period
196
days.
PVA
fibers
helped
bridging
provided
nucleation
sites
for
enhanced
calcite
precipitation.
Similarly,
AEA
also
encapsulating
sealing
up
0.25
mm,
when
conjunction
LECAs.
Furthermore,
tests
formation
as
product
within
bioconcrete.
study
offer
valuable
insights
construction
industry,
highlighting
ability
bacteria
reduce
structures
promoting
sustainable
approach
minimizes
need
manual
repairs,
particularly
hard-to-reach
areas.
