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Файл:The bases of special methods of biomass processing into prospective materials. Tutorial
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1.4. Technology of advanced biomass processing. Classification
Technology of advanced biomass processing can be divided into
mechanical and chemical.
Production of wood flour, pine vitamin flour and pine sap refer to
mechanical way of processing.
Essential oils obtaining and technology of extractive processing of
wood foliage are considered to be chemical ways of processing.
Technology of extractive wood foliage processing consists of the following
activities. Bioactive substances are retrieved from milled raw material using
different solvents. These bioactive substances are concentrated, chemicallytreated and used as a final product or as a raw material for different
concentrates extraction or in compounds with valuable properties.
1.5. Technology testing
«Technology for producing composite materials
based on wood particles and cement»
Objectives: to make specimens from wood particles and cement in
the laboratory; to learn the effect of preparation parameters, component
ratios on physical and mechanical properties of resulting products.
Materials and reagents:
– softwood particles in the form of regrind, chips and sawdust. Bulk
density is 120–150 kg/m3;
– the binder is Portland cement grade 400 or 500;
– chemical additives are calcium chloride and liquid sodium glass.
Equipment:
– testing sifter;
– molds;
– weight for pressing;
– balance;
– container for weighing components;
– container for mixing components;
– hydraulic press;
– testing machine;
– a laboratory oven with temperature of 103
0
C;
– ruler.
11
Procedure
№
Number of components
The
aggregate, g
The
binder, g
Total amount of water
Chemical
For prewetting, ml
In the
binder,
ml
Additives
1
100
75
50
100
2 % by
weight of
the
aggregate
2
100
100
50
130
3
100
125
50
160
1. The components for making specimens are shown in table 1.1.
Table 1.1
The components
Make specimens from wood particles and cement in the laboratory.
The sequence of the specimens making process:
– measure the mass of the aggregate for three specimens on the
balance in series;
– measure the mass of the cement for three specimens in series;
– mix wood particles and cement with water and chemical additives
in the desiccators until uniform impregnation for three specimens in series;
– fill the molds with the mixture and press with weight for 5–7 min;
– put the specimens in the laboratory oven at a temperature of 80–
90 0 C and humidity of 50–60 % for 4 hours;
– take the specimens from the molds;
– keep the specimens in the laboratory at a temperature of 18– 20 0C
for 5 days.
2. Test physical and mechanical properties of the resulting specimens
in accordance with standard methods. Physical properties are tested in
accordance with GOST 19222-84 “Arbolit and its products. General
specifications”. Strength is tested in accordance with GOST 10180-90
“Concretes. Methods for strength determination using reference
specimens”.
12
2.1. Determination of strength and modulus of elasticity in bending
Preparing the specimens for testing
The specimens should be tested at positive air temperature and the
required strength of concrete (set in accordance with GOST 18105)
corresponding to its class approved in the project. The specimens, kept at
negative air temperature or entered the test immediately after hydrothermal
treatment, have to be placed at the temperature of more than 15 0C for a day
before testing.
Testing
In control tests the specimens should be brought to destruction that
characterizes by the continuous growth of deflections, the formation of
cracks and their opening at practically constant maximum load.
Processing results
The strength of the specimens is calculated by the peak breaking load
registered when the first signs of the destruction appear. The strength is
assessed on comparisons of actual breaking load and the control breaking
one, which is set in the standard or design documentation for the product.
The specimens are found to meet strength requirements if breaking load is
not less than 100 % of control one when testing one of the specimens.
2.2. Determination of density
Preparing the specimens for testing
The density of concrete depends on its moisture content. While
determining the density of concrete in a state of natural humidity, the
specimens are tested immediately after sampling. They also can be kept in a
vapor-proof packaging or in a hermetically sealed container if its capacity
does not exceed double volume of the specimens in it. The density of
concrete specimens with regulated moisture content is calculated using the
formula. While determining the density of dry concrete, the specimens are
dried to a constant weight in accordance with GOST 12730.2. While
determining the density of air-dry concrete, the specimens are placed before
testing in a room at a temperature of 25 ± 10 0 C and the relative humidity
50 ± 20 % at least for 28 days. While determining the density of concrete
with normal moisture content, the specimens are kept in the curing
chamber, in the hermetically sealed container at the relative humidity not
less than 95 % and at a temperature of 20 ± 2 0 C for 28 days. While
determining the density of water-saturated concrete, the specimens are
saturated with water in accordance with GOST 12730.3.
13
Testing
№ of the
specimen
Mass,
kg
Volume,
m
3
Density,
kg/m
3
Breaking
strength,
kg/s
Strength,
MPa
1
2 3
The volume of specimens with a regular shape is calculated from
their geometric dimensions. The specimens’ sizes are measured with a ruler
or a caliper with a margin error 1 mm by the method of GOST 10180.
The specimens’ masses are measured using the balance with a margin error
0.1 %.
Processing results
The density of a concrete specimen ρ expressed in kg/m3 is calculated
with a margin error 1kg/m3 using the formula below:
where m – the mass of a specimen, kg;
v – the volume of a specimen, m3.
The density of specimens is calculated as the arithmetic mean of the
test results of series of all specimens.
The density of concrete with normalized moisture content ρн expressed
in kg/m3 is calculated using the formula below:
where ρw – the density of concrete at Wm humidity, kg/m3;
Wn – normalized moisture content of concrete, %;
Wm – moisture content of concrete while testing, %.
2. Present the results of the research in the form of a table:
14
Technologies for obtaining the composite materials based on cement (CSP,
Type of
WMCM
Density,
kg/m
3
Material
compositeon
Modes
Properties
Application
CSP
1100 –
1400
Filler.
Disbarked
pinewood
(content of
bark and
touchwood
is > 5 %,
content of
water based sugars
is no more
than 0.5 %
(for
hardwood
– 0.2 %),
of tanning
agents
tannins) is
no higher
than 0.4 %,
of oils, fats
and wood
Molding at
1.8–2 MPa.
Thermal
treatment at
50–80 0С
and 50–
60 %
humidity for
6–8 hours
form
removal and
hardening at
16 0С for
7–14 hours
of
drying at
80–100 0С
Materials are
nonflammable,
fireproof and
biostable, show
lower absorption figures
than WPB and
FB. They have
extended water resistance,
are resistant to
low
temperature
exploration and
effect of
atmospheric
precipitations;
possess high
sound
insulation and
with-stand
Materials
can be used :
1) as a bearing component,
screens,
coffers of
“sandwich”
panels with
plastic
foam inner,
for manufacturing
furniture
fronts,
dividing
walls, floors,
ceilings,
building
units like
(stools,
sidings,
2. TECHNOLOGY OF COMPOSITE MATERIALS
MANUFACTURE
2.1. Technologies for obtaining the composite materials based
on mineral binding agent
Table 2.1
cement wood, sawdust concrete, velox)
15
tars is no
higher than
1.5 %) as a
specially
prepared
thin wood
wool
Matrix.
Brand 500
Portland
cement
without
flexibilizer,
content of
slag
additive is
no more
than 5 %.
Chemical
additives.
Liquid
glass and
aluminium
sulphate
compressive
load perpendicular to
face.
Disadvantages
are: low shock
resistance,
high bulk
density, low
bending
resistance.
Materials are
tough to
machine.
fences); in
constructions with
high firesafety requirements;
2) in wood
panel house-building
they are
used as
cladding
and screens
for wooden
houses;
3) produce
factorymade
houses
Cement
wood
400–
850
F.
Woodworking waste,
annual
plant waste
(bun waste,
flax waste,
cotton
Molding
hardening
occurs in
natural
conditions
at atmospheric temperature of
no
Material is
easily drilled,
cut and
plastered. It
can be nailed
and screwed.
It is firehard,
doesn’t fail in
water.
Material is
Cement
wood is used
for
manufacturi
ng wall
panels and
blocks; roof
slabs and
floor slabs,
with rein-
Table continuation 2.1
16
stalk
ground
waste,
bulrush
waste).
Bark
content
should be
no more
than
10 %, of
pine and
leaves –
no more
than 5 %
as hogged
chips.
M.
Portland
cement
and rapidhardening
Portland
cement,
sulfateresistant
cement,
colored
Portland
cement of
the brand
no lower
than 300
for heatinsulating
cement
wood and
lower than
15 0С with
relative
humidity
of 60–
80 %,
during 4–5
days; in
heat
chambers
at temperature of no
higher than
40 0С and
relative air
humi-dity
of 50–
60 %; by
means of
elec-trical
heater at
temperatur
e of no
higher than
50 0С.
Form
removal:
molding
time in a
shop at a
temperatur
e of no
lower
frost proof
and biostable, nonhydroscopic,
possesses
low heat and
sound
conductivity
and strength
forced
concrete
beams;
partition
slabs for
community
and commercial
buildings;
heat and
sound
insulating
slabs; space
structures
Table continuation 2.1
17
brand
400 – for
structural
cement
wood.
Ch. Ad.
Calcium
chloride
and
calcium
nitrate,
papermaker’s
alum, liquid soda
glass
than 15
0
С for 5–6
days.
Sawdust
concre
te
6001200
F. All
kinds of
wood as
sawdust.
M. M–
400
cement
brand.
Ch.Ad.
Calcium
chloride,
lime and
liquid
glass.
Mineral
additives.
Sand of
coarse
and medium frac-
Prelimina
ry drying
for 5–12
hours
form
removal
finish hardening in
shop floor
during 5–
7 days
Material is
environment
ally friendly,
possesses
unique sanitarycharacteristics.
Water absorption of the
material is
the same as
in traditional
building materials (like
foam concrete, aerated
concrete,
brick).
Freeze-thaw
durability
and fire-
Material is
used as
constructiveisolative
material
(wall panels, partition panels)
Table continuation 2.1
18
tion, with
content of
fine sand
no lower
than
10 %. Clay
content
must not
be higher
than
0.5 %
resistance are
higher than
that of poly-
styrene con-
crete, i. e. it
is almost
noncombusti
ble. A saw-
dust concrete
wall 40 cm
thick exceeds
100 cm
brickwork in
resistance
and heat
transfer; it
exceeds
traditional
building ma-
terials in
strength
Velox
F. Up to
90 % of
panel
volume
consist of
spruce
thinners
(big and
old trees
don’t go
into pro-
duction),
with bark
content of
no more
than >3 %
Molding
hardening
occurs in
a chamber
at 40 0C
and
humidity
of no
more than
> 50 %
for 24
hours
form re-
moval
indoor
vertical
A 320 mm
thick velox
walls
substitute a
meter-thick
brick wall in
thermoresis-
tance. It
allows to
enlarge the
size of buil-
dings at the
cost of shal-
low wall
thickness and
lighten the
Velox is
used for
rapid heatinsulating
housing
construction:
for construction of
outside and
interior
walls, floor
structures
and roof
coating.
Table continuation 2.1
19
as shred.
M.
Cement.
Ch. Ad.
Liquid
glass,
Al2SO
4
drying
with a fan
heater for
7 days
load on
foundation at
the cost of
low const-
ruction; a
320 mm
thick velox
walls provide
thermal
protection of
buildings
according to
the
requirements
of State
Standard
16381-77
«Building
and heat-
insulating
materials»
and II-379
II-type of
Construction
rules and
regulations;
Velox walls
provide
protection
from outside
noise and
impact noise
coming from
inside.
Panels
possess high
strength and
can be used
as deck in
constructin
g cast
concrete
structures
and
inserted
floors. Heat
insulation
material
(like,
silicate
cotton) is
glued
between
external
deck panel
and con-
crete;
Velox can
be applied
in recon-
struction
and general
overhaul of
old housing
as low
weight of
Velox
construc-
tions gives
an oppor-
tunity to
build on
additional 1
Table continuation 2.1
20
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