Scientific Reports,
Год журнала:
2024,
Номер
14(1)
Опубликована: Дек. 28, 2024
Saline
soil
is
widely
distributed
in
China
and
poses
significant
challenges
to
engineering
construction
due
its
harmful
effects,
such
as
salt
heaving,
dissolution
collapse,
frost
heaving.
The
Microbial-Induced
Calcite
Precipitation
(MICP)
method
an
emerging
environmental-friendly
modification
that
can
reduce
or
eliminate
the
environmental
hazards
of
saline
soil.
To
verify
feasibility
MICP
for
improving
properties
soil,
laboratory
tests
were
conducted
study
effects
content,
activated
carbon
content
freeze-thaw
cycles
on
compression
water
retention
behavior
modified
following
conclusions
drawn:
calcium
carbonate
produced
from
cement
particles
structures,
which
resists
expansion
damage
caused
by
heaving
reduces
compressibility.
Additionally,
fill
pores
improves
capacity
addition
enhance
reaction
leading
further
reduction
compressibility
enhancement
Buildings,
Год журнала:
2024,
Номер
14(12), С. 3782 - 3782
Опубликована: Ноя. 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.
Materials,
Год журнала:
2025,
Номер
18(11), С. 2514 - 2514
Опубликована: Май 27, 2025
The
formation
and
spatial
uniformity
of
calcium
carbonate
(CaCO3)
are
critical
for
evaluating
the
effectiveness
microbial-induced
precipitation
(MICP)
in
geotechnical
applications.
In
recent
years,
single-phase
injection
method
has
emerged
as
a
promising
alternative
to
traditional
two-phase
processes
by
addressing
issue
uneven
CaCO3
distribution.
This
study
proposes
dual
inhibition
strategy
that
delays
mineralization
reaction
synergistically
lowering
pH
temperature,
thereby
promoting
uniform
enhanced
compressive
strength
cemented
sand
columns.
A
series
experiments,
including
bacterial
growth,
aqueous
reaction,
column
reinforcement,
microstructural
characterization,
were
conducted.
Results
show
minimum
required
flocculation
increases
from
~4.5
at
40
°C
~6.0
10
°C.
Under
inhibition,
lag
period
effectively
improved
enabled
complete
utilization
within
24
h.
After
four
treatment
cycles,
content
increased
53%,
unconfined
reached
2.5
MPa,
50%
improvement
over
condition.
XRD
analysis
confirmed
calcite
was
dominant
phase
(85–90%),
accompanied
minor
vaterite.
These
findings
demonstrate
adaptability
efficiency
across
temperature
ranges,
providing
cost-effective
solution
broader
engineering
