CD07-001
THE STUDY OF VELOCITY AND FREQUENCY OF PASSING
WATER THROUGH A MAGNETIC FIELD AND ITS EFFECT ON
THE COMPRESSIVE AND TENSILE STRENGTH OF CONCRETE
H. Safaye Nikoo
Faculty member of Chabahar Maritime University, Chabahar, Iran
ABSTRACT
Concrete is a material which can have a range of different strengths with using
different ratio s of its composites. In this regard, every factor that can help us reach
better mechanical properties and other characteristics of concrete is worth studying.
In our study, regarding above information, we study the effects of water properties
(considering magnetizing water) of concrete on some of the mechanical features of
concrete containing microsilica such as compressive and tensile strength at
different curing ages. The water in concrete has been passed through magnetic field
with velocities such as Q, Q/2, Q/3, Q/6 and with 1, 3 and 6 passing times. The
results indicate that increasing the number of times water is passed (from 1 to 6),
improves the compressive and tensile strength of concrete, and decreasing the
velocity of passing water through magnetic field in one cycle (from Q to Q/6) has a
similar result. The improvement of decreasing the velocity in one cycle is more
significant than the improvement caused by passing water through a number of
times, and the compressive and tensile strength will be improved substantially. the
compressive and tensile strength of concrete will be increased up to 15 % .This
method is considered very economical and does not need special equipments in
industry.
Keywords: microsilica, magnetic water, superplasticizer, compressive
1. INTRODUCTION
Henrico Anton Lorenz (1920) introduced the effect of the magnetic field on water
that got the Nobel Prize. He found that, under the effect of a magnetic field, polar
molecules are arranged and separated, therefore, water becomes lighter. When the
molecules pass through a magnetic field, a change in their arrangements appears.
Since each water molecule is like a little magnet, as shown in Figure 1, by passing
through the magnetic field, they arranged in an end - to - end way; This is called
polarity. Water molecules are not separated; they are attached to each other as a
group by a hydrogen bond. The lesser the number of molecules are in this group of
molecules, their activity will be more. The magnetic field helps to this process
(Figure 2).
988 / The Study of Velocity and Frequency of Passing….
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A
Figure 1. Effect of the magnetic field on
molecules arrangement
B
Figure 2. Effect of the magnetic field
gathering of water molecules A) Before
passing through the magnetic field B)
After passing through the magnetic field
The general principle of magnetic technology is based on the interactions between
a magnetic field and a moving electrical charge, in form of an ion in this system.
When the ions pass through a magnetic field, some force is given to each single
ion. In case, the orientation and the charge of the ions are against each other, it
causes a fluctuation in the ions which, as a result, leads to the formation of
sediment. The magnetic fields lead to the induction of electrical charge through
positive and negative ions. As a consequence, ions of different charges repel each
other instead of attracting each other. Therefore, a negative and a positive ion of
the same charge that should form sediment, cannot approach enough to each other.
Magnetic processing of water system is categorized in two and three, forms of
installation and operation, respectively. Magnetic system may be installed inside or
outside the flow. The inner systems are those which all or part of them is on the
way of the flow. The outer systems are completely out of the water flow, thus they
can be installed on the pipe (Figure 3) [1].
In terms of the kind of the operation these systems are categorized in the following
way:
1. Magnetic: Mostly a permanent magnet.
2. Electromagnetic: In which the magnetic field is provided by the electromagnetic.
3. Electrostatic: In which the electrical field is forced into the water flow, which
leads to the production of a magnetic field and, as a result, it attracts or repels the
ions. The electrostatic units are always inside, whereas the other two kinds can be
either inside or outside (outer) [1].
The degree of magnetization of water depends on three factors:
- The amount of the liquid in contact with the magnet.
- The power of the used magnet.
- The period of time that the liquid is in contact with the magnet.
During the recent years, there have been few researches carried out about the effect
of magnetized water on the properties of normal concrete. In these researches,
normal water was passed through a magnetic field in a frequency and with a
specified velocity, and then this water was used in the mix designing. The result of
these researches was an increase in the strength and other mechanical properties of
concrete.
––––––––––––––––––––––– 3rd International Conference on Concrete & Development / 989
If water passes through a magnetic field during one or more frequencies or with
different velocities, the behavior of the strength properties of the concrete
containing Microsilica is studied in this research.
Figure 3. Different kinds of magnetic systems in terms of the place of installation
2. EXPERIMENTAL PROCEDURES
2.1. Properties of the Used Materials
2.1.1. Cement
The cement used in making concrete specimens of normal Portland cement type II
of KHASH cement factory is based on the ASTM standard [3]. The unite weight
obtained is 3.157 gr/cm3. Tables 1 and 2 represent physical properties and results
of the chemical analysis of the specimen, respectively.
2.1.2. Aggregates
Natural coarse (Gravel) and fine aggregates (Sand) are used to make the
specimens. Different properties of the aggregates used, such as the unit weight (in
terms of dry, saturated, and apparent), water absorption and their grading are
obtained (Tables 3 and 4). Water absorption of the aggregates, represents the
amount of the moisture of the aggregates in a saturated - dry surface (SSD).
Table 1: Physical and mechanical properties of Portland cement type II [3]
Setting time
Hydration heat
Compressive strength (Kg/cm2)
(minute)
(cal/gr)
28 days
7 days
3 days
final
initial
7 days
28 days
> 380
> 270
> 170
< 200
> 70
< 70
< 80
Table 2: Results of the chemical analysis of Portland cement type II [3]
Chemical
SO3
MgO
CaO
Fe2O3
Al2O3
SiO2
compound
<2.0
<2.3
63.2-64.8
3.6-4.3
4.7-5.4
21.0-22.2
percentage
Chemical
Na2O+0.658K2O
F.Cao
L.O.I
Lns.Res
Cl
compound
<1.0
<1.3
<1.0
<0.65
<0.05
percentage
Grading represents the amount of distribution and presence of different sizes of
aggregates in a sand or gravel specimen. The size of an aggregate is the average
diameter that can be considered for the aggregate. Therefore, dividing an aggregate
990 / The Study of Velocity and Frequency of Passing….
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into grains of the same size, is the definition of grading [4]. This grading of fine
aggregate (sand) and coarse aggregate (gravel), as shown in diagrams 1 and 2, is
experimentally obtained.
Table 3: Unit weight based on the results of the test (Kg/m3)
The apparent unit
The actual saturated
The actual dry
Aggregate
weight
unit weight
unit weight
2718
2673
2646
Gravel
2607
2576
2556
Sand
Table 4: The 24-hour water absorption aggregates based on the results of the test
Percentage of water absorption
Aggregate
1.005
Gravel
0.76
Sand
2.1.3. Water
Drinking water is used in carrying out tests and making specimens. To magnetize
water it was first poured in to a system (at the end of which a pipe was attached
from outside and in some parts of the pipe the AQUA apparatus (Figure 5) was
installed, and there were two valves before and after the apparatus (Figure 4)), and
after the water went out of the vessel and passed through a magnetic field, in case
the valve installed at the end of the AQUA was turned on, it would pass through
the pipe into the vessel 2 and it would be used in making specimens, immediately.
If the objective was to repass the water through the magnetic field, the water in
vessel 2 would be re-poured into vessel 1, and this would be done as many times as
required. If the objective was passing the water with a lower velocity less than that
of the basis, the valve before the AQUA was turned on so that the water could pass
through the magnetic field with the desired discharge. Flow meters were used to
control of the velocity of the water.
2.1.4. Admixtures
In this study silica fume (S.F) was used with the average grain of 0.2 µm and an
actual specific weight of about 2.2 gr/cm3. To study the extra effect of silica fume
in concrete, specimens of 10% and 20% of silica fume were made as substitutes for
cement and different results of the compressive and tensile strengths were obtained
from magnetized water. Because of an increase in the viscosity and cohesiveness of
the matrix and a decrease in the workability of concrete due to the use of silica
fume, superplasticizer was used.
2.1.5. Superplasticizer
Superplasticizers are used in naphthalene formaldehyde sulphonate tests. This
material is used as liquid in the form of solution in water. It is dark brown and has
a specific weight of 1.2gr/cm3.
100
100
90
90
80
70
60
50
Allowable Confine
40
Allowable Confine
30
S and
20
10
0
Percentage of passing through the sieve
Percentage of passing through the sieve
––––––––––––––––––––––– 3rd International Conference on Concrete & Development / 991
80
70
60
50
Allowable Confine
40
Allowable Confine
30
Gravel
20
10
0
0.01
0.1
1
10
100
diameters of the grains (mm)
Diagram 1. Grading graph of fine
aggregate (sand) and ASTM domain
1
10
100
diameters of the grains (mm)
Diagram 2. Grading graph of coarse
aggregate (gravel) and ASTM domain
vessel
1
vessel 1
1
2
VALVE 1
VALVE 2
AQUA
vessel 2
Figure 4. Water magnetizing system
Figure 5. Aqua-correct system
2.2. Properties of the Mix Designings
Properties of parts of the concrete mixture made with magnetized water (during
different frequency or different velocities in a frequency) are calculated with
absolute volume method and are shown in Table 5. CO1 to CO4 represent
specimens made with normal water and are considered as the observer concrete.
CN and CV represent specimens made with magnetized water in different
frequencies and specimens made with magnetized water in different velocities,
respectively.
Notes:
1. Q is the base discharge and is 105.8 cm3/s.
2. In all Tables, the quantity of Q is cm3/s.
3. In represents the number of magnetization of water cycles.
4. In this study, concrete specimens were made in which density of the cement
5. as 400 kg/m3, the water to cement were 0.5 and 0.4 ratios and also 10% and
20% of Microsilica.
6. According to the fact that silica fume is a cement material, cement materials
(B=C+S.F.) are used instead of cement, and water to cement material ratios
992 / The Study of Velocity and Frequency of Passing….
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(W/B) instead of water to cement (W/C) in the calculations and Table of the
mix designings.
7. The maximum amount of the superplasticizer is limited to 2% of the weight of
the cement materials.
8. The amount of the air in these specimens is 2% of the volume of the concrete.
9. The average amount of slump is 60 mm.
10. The maximum size of the aggregates is 19 mm.
2.3. Details of the Specimens and the Preserving Method
Specimens were made to carry out the concrete compressive and tensile strength
tests, which will be discussed later.
٢٢٩٧٫٠٥
١٠٥٫١٨
٠
specimen
n
Q
specimen
n
Q
specimen
n
Q
٨٠
٢٫٢٣
٤٠
١٫١٢
٨٠
٢٫٢٣
٤٠
١٫١٢
٣٢٠
٨٫٩٣
٣٦٠
١٠٫٠٤
٣٢٠
٨٫٩٣
٣٦٠
١٠٫٠٤
١٦٠
٤٫٤٦
١٦٠
٤٫٤٦
٢٠٠
٥٫٥٨
٢٠٠
٥٫٥٨
٦٥٤٫٣٤
١٨٫٢٦
٦٦٧٫١٢
١٨٫٦١
٥٥٢٫٠٩
١٥٫٤٠
٥٦٤٫٨٨
١٥٫٧٦
١١٣٠٫٢۵
٣١٫٥٤
١١٣٠٫٢۵
٣١٫٥٤
١١٣٠٫٢۵
٣١٫٥٤
١١٣٠٫٢۵
٣١٫٥٤
specimen
٠
٤٠٠
١١٫١٦
٤٠٠
١١٫١٦
٤٠٠
١١٫١٦
٤٠٠
١١٫١٦
ratio of water to cement
١٠٥٫١٨
٤٫١٠
٠٫١١
١٫٦٠
٠٫٠٤
٢٫١٤
٠٫٠٦
١٫٩٢
٠٫٠٥
Percentage of microsilica
٢٢٨٤٫٤٨
Gravel (G)
٠
Sand (S)
١٠٥٫١٨
Water (W)
٢٣٥٨٫٩٧
Cement (C)
٠
Microsilica (S.F)
Number of water magnetic frequency
(n)
١٠٥٫١٨
B= C+S.F
Amount of the basic passing discharge
٢٣٤٨٫٦٩
Superplasticizer
Calculated specific weight
Table 5: The amounts of the mix designing (Kg/m3)
٢٠
٠٫٤
CO1
١٠
٠٫٤
CO2
٢٠
٠٫٥
CO3
١٠
٠٫٥
CO4
Table 6: comparison of the specimens W/B=0.4 , S.F=20%
CO1
CN1
CN5
CN9
CV1
CV5
٠
١٠۵٫١٨
١
١٠۵٫١٨
٣
١٠۵٫١٨
٦
١٠۵٫١٨
١
٥٢٫٥٩
١
٣٥٫٠٦
Table 7: Comparison of the specimens W/B=0.4 , S.F=10%
CO2
CN2
CN6
CN10
CV2
CV6
٠
١٠۵٫١٨
١
١٠۵٫١٨
٣
١٠۵٫١٨
٦
١٠۵٫١٨
١
٥٢٫٥٩
١
٣٥٫٠٦
Table 8. comparison of the specimens W/B=0.5 , S.F=20%
CO3
CN3
CN7
CN11
CV3
CV7
٠
١
٣
٦
١
١
١٠۵٫١٨ ١٠۵٫١٨ ١٠۵٫١٨ ١٠۵٫١٨ ٥٢٫٥٩
٣٥٫٠٦
CV9
١
١٧٫٥٣
CV10
١
١٧٫٥٣
CV11
١
١٧٫٥٣
––––––––––––––––––––––– 3rd International Conference on Concrete & Development / 993
Table 9. comparison of the specimens W/B=0.5 , S.F=10%
specimen
n
Q
CO4
٠
١٠۵٫١٨
CN4
١
١٠۵٫١٨
CN8
٣
١٠۵٫١٨
CN12
٦
١٠۵٫١٨
CV4
١
٥٢٫٥٩
CV8
١
٣٥٫٠٦
CV12
١
١٧٫٥٣
A) Compressive strength test
Standard 10*10*10 cm moulds were used in making compressive specimens. To
specify the compressive strength three specimens were made to be tested at each
age, meaning that for each design, three cubic specimens for the compressive
strength test at the age of 7 days, three cubic specimens for the compressive
strength test at the age of 14 days and three cubic specimens to be test at the age of
28 were made and the average results of the test of the three specimens were placed
into the pervious results. On the whole 252 cubic 10*10*10 cm specimens were
made to specify the strength terms of 7, 14 and 28 days. To convert the
compressive strength resulted from the cubic specimens to the standard cylinder,
the proposed factors of Iranians Concrete Regulations were used. The strengths
obtained, are the average of the strengths of the three concrete specimens made in
the laboratory, and are shown in the table. [5]
B) Tensile strength test
15*30 cylindrical specimens and the Brazilian test method were used to achieve the
tensile strength. Three models were made for each specimens and the average of
the result are shown in Tables and Figures. All the tensile specimens of the age of 7
and 28 days were tested. Totally, 168 cylindrical specimens (15*30) were made of
the age mentioned.[5]
3. RESULTS
Two subjects are studied in this part of the research. The first section compares the
effect of two techniques of magnetizing water (passing water through the magnetic
field in different frequencies or passing it through this field with different
velocities) on the compressive and tensile strength. The results of the two
techniques are studied in the second part.
3.1. Compressive and Tensile Strength
The results are shown in Table 10.
3.2. Results Discussing
In this part, due to the variety of the existing designs and the results obtained in the
previous parts, examining and comparing the concretes made with the maximum
compressive and tensile strengths (the designs with magnetized water in six
frequencies or magnetized water with water passing through a magnetic field as
much as 1/6 of the base passing discharge) with the observer concrete are studied.
994 / The Study of Velocity and Frequency of Passing….
––––––––––––––––––
Table 10. Results of average compressive and tensile strength of specimens of different
ages (MPa)
Average
28-days
tensile
strength
٣٫١۵
٢٫٧٧
٢٫۶٨
٢٫۴۴
٣٫٢٧
٣٫٠۴
٢٫٨١
٢٫۵٩
٣٫٣۶
٣٫٢١
٣٫٠١
٢٫٧٢
٣٫٣٧
٣٫١٩
٣٫٠۵
٢٫٨٩
٣٫۴٠
٣٫٢٠
٣٫١۶
٢٫٨٩
٣٫۵١
٣٫۴١
٣٫٢٧
٣٫٠٠
٣٫۴۵
٣٫٣۵
٣٫٣۴
٣٫١٩
Average
7-days
tensile
strength
٢٫٣٣
١٫۵٨
١٫٧٣
١٫٢۵
٢٫۵٢
١٫٧٩
١٫٨۶
١٫٣٨
٢٫۶۵
١٫٩١
٢٫١٧
١٫۵١
٢٫٧١
٢٫١١
٢٫٠٢
١٫۶۴
٢٫٧٩
١٫٩٩
٢٫٢۴
١٫۶٠
٢٫٩٠
٢٫١٣
٢٫٣٩
١٫٧٧
٢٫۵٩
١٫٨١
٢٫۵١
١٫٩٢
Average
28-days
compressive
strength
۴٠٫۶
٣۴٫۵
٣٣٫١
٢٨٫٩
۴٣٫٩
٣٩٫۵
٣٨٫١
٣٣٫۴
۴۴٫٢
۴٠٫٢
٣٨٫٣
٣٣٫۶
۴۴٫٧
۴٠٫۵
٣٨٫٩
٣۴٫١
۴۴٫٩
۴١٫۵
۴٠٫٨
٣۶٫۴
۴۶٫٨
۴٣٫٢
۴٢٫۶
٣٨٫٢
۴٧٫٩
۴۴٫٧
۴۴
۴٠٫۶
47.9
45
41.1
40
38
34.8
35
30
28.1
25
24.9
20
44.7
T ensile Strength (M Pa)
Compressive Strength (MPa)
50
Average
14-days
compressive
strength
٣۴٫٨
٢٩٫۶
٢٨٫۴
٢۴٫٨
٣٧٫٣
٣٣٫٢
٣٢٫١
٢٨٫١
٣٧٫٧
٣٣٫٧
٣٢٫۵
٢٨٫۴
٣٨٫٠
٣۴٫٠
٣٢٫٧
٢٨٫٧
٣٨٫٢
٣۶٫٨
٣۴
٣٢٫۴
٣٩٫۶
٣٨٫٣
٣۵٫٩
٣۴٫۴
۴١٫١
٣٩٫٨
٣٧٫۶
٣۵٫٨
40.6
23.2
CO1
15
CN9
10
CV9
5
0
7
14
21
Time ( Day )
28
3.50
3.15 3.37
3.45
3.00
2.71
2.59
35
Diagram 3. Effect of magnetizing water on
the compressive strength of concrete of
different ages
Specimen
CO1
CO2
CO3
CO4
CN1
CN2
CN3
CN4
CN5
CN6
CN7
CN8
CN9
CN10
CN11
CN12
CV1
CV2
CV3
CV4
CV5
CV6
CV7
CV8
CV9
CV10
CV11
CV12
2.50 2.33
2.00
1.50
1.00
0.50
0.00
0
Average
7-days
compressive
strength
٢٣٫٢
١٩٫٧
١٨٫٩
١۶٫۵
٢٣٫٧
٢٠٫١
١٩٫۴
١۶٫٩
٢۴٫۴
٢٠٫٩
٢٠٫٠
١٧٫۶
٢۴٫٩
٢١٫٢
٢٠٫۴
١٩٫۶
٢۴٫٩
٢٢٫۵
٢١٫١
١٨٫٧
٢۶٫١
٢٧٫١
٢٢٫٨
٢٠٫٢
٢٨٫١
٢۵٫٩
٢١٫۵
٢١٫٩
CO1
CN9
CV9
Time (Day)
Diagram 4. Effect of magnetizing water
on the tensile strength of concrete of
different ages
––––––––––––––––––––––– 3rd International Conference on Concrete & Development / 995
3.2.1. Concrete with 0.4 Water to Cement Ratio and Containing 20% of Microsilica
The results of the comparison between this mix designing in the concrete with
normal water and with magnetized water (in six frequencies and with a passing
velocity of 1/6) are shown in diagrams 3 and 4. As illustrated in these figures, the
magnetization of water causes an increase in the compressive and tensile strength.
Furthermore, the induction of the magnetic property into water, by passing it
through a magnetic field with 1/6 of the base velocity, compared with the number
of processing frequencies causes more increase in the strength.
3.2.2. Concrete with 0.4 Water to Cement Ratio and Containing 20% of Microsilica
A comparison between the results of the diagrams 5 and 6 shows that due to
magnetizing water, mechanical properties (including the compressive and tensile
strength) will improve. For example, by increasing the number of magnetic
processing frequencies of water, the 28 days compressive and tensile strengths of
the concrete, in comparison with the observer specimen, will increase by 17.3 and
15.1, respectively.
39.8
40
35
34
30
25.9
21.2
25
20
40.5
34.5
29.6
19.7
15
CO2
10
CN10
5
CV10
7
14
21
Time (Day)
28
35
Diagram 5. Effect of magnetizing water
on the compressive strength of concrete
of different ages
3.35
2.77
3.00
2.50
2.11
2.00 1.58
1.81
1.50
1.00
0.50
0.00
0
0
3.19
3.50
44.7
45
Tensile Strength (MPa)
Compressive Strength ( MPa )
50
CO2
CN10
CV10
Time (Day)
Diagram 6. Effect of magnetizing water on
the tensile strength of concrete of
different ages
Induction of magnetic property by decreasing the velocity of water passing through
the field, causes an increase of 29.6% and 20.8% in these strengths. Therefore,
magnetizing water via decreasing its velocity of passing through the magnetic field
causes more increase in the compressive and tensile strengths of the concrete.
3.2.3. Concrete with 0.5 Water to Cement Ratio and Containing 20% of Microsilica
Results obtained from this comparison are shown in diagrams 7 and 8. According
to these results, the concrete containing magnetized water, will have its maximum
of tensile and compressive strength via decreasing the velocity of water passing
through the magnetic field. For example, via this method of magnetizing water, the
tensile and compressive strength will, in comparison with the observer concrete,
increase by 24.6% and 32.9% respectively, whereas by increasing the number of
magnetic processing, these two quantities will, in comparison with the normal
996 / The Study of Velocity and Frequency of Passing….
––––––––––––––––––
specimens of water, increase by 13.5% and 17.5%, respectively.
50
3.50
44
40
37.6
35
38.9
32.7
30
25
21.5
20.4
18.9
20
15
Tensile Strength (M Pa)
Compressive Strength ( MPa )
45
33.1
28.4
CO3
10
CN11
5
CV11
0
7
14
21
Time (Day)
28
3.00
2.50
2.00
35
Diagram 7. Effect of magnetizing water on
the compressive strength of concrete of
different ages
3.34
2.51
2.02
1.73
1.50
1.00
0.50
0.00
0
3.05
2.68
CO3
CN11
CV11
Time (Day)
Diagram 8. Effect of magnetizing water
on the tensile strength of concrete of
different ages
4. CONCLUSION
Looking of the fact that, optimized strengths are obtained by magnetized water
with six frequencies or 1/6 of the base discharge, the results of examining the
laboratory results of this study and the final conclusion of the information there in
are as follows:
- Generally, by once magnetizing water, the average changes in the compressive
and tensile strength, will in comparison with normal water, be about 9% and
8.5%, respectively whereas the average amount of the increase in the
compressive and tensile strength of all ages, by once to three times of
magnetizing will, respectively be about 1.9% and 6.1% and with three to six
times of magnetizing will be 2.1% and 1.8%. This is the case that magnetizing
water via passing in through the magnetic field with the velocity of 1/2 of the
discharge, the averages in the compressive and tensile strength, is respectively
in comparison with normal water, about 17.6% and 20.4% whereas the average
amount of the increase in the compressive and tensile strength from 1/2 of the
discharge to 1/3 at all ages in respectively 6.5% and 5.6% and from 1/3 to 1/6 of
the discharge is about 3.2% and 0.9%.
According to what has been mentioned:
1. Increasing the number of magnetizing water frequencies (from 1 to 6) and also
decreasing the velocity of water passing through the magnetic field (from Q to
Q/6), the average increase in the strength will face a decline.
2. six times of magnetizing water will change the average compressive and tensile
strength, at all ages, to about 13% and 16.6% in comparison with the concrete
made with normal water, where as by water passing with a velocity of 1/6 of
the base passing discharge the average compressive and tensile strengths, at all
ages, will respectively change about 27.3% and 25.1% in comparison with the
––––––––––––––––––––––– 3rd International Conference on Concrete & Development / 997
concrete made with normal water. Therefore,
3.19
3.50
45
40.6
40
T en sile S tren g th (M P a )
Compressive Strength ( MPa )
50
35.8
35
28.7
30
25
21.9
20
19.6
28.9
24.8
16.5
15
34.1
CO4
10
CN12
5
CV12
0
7
14
21
Time (Day)
28
2.50 2.44
2.00
35
Diagram 9. Effect of magnetizing water
on the compressive strength of concrete
of different ages
1.92
1.64
1.50 1.25
1.00
0.50
0.00
0
2.89
3.00
CO4
CN12
CV12
Time (Day)
Diagram 10. Effect of magnetizing water
on the tensile strength of concrete of
different ages
A) Magnetizing water vi decreasing the velocity of water passing though the
magnetic field, in comparison with the other technique of magnetizing water
(by increasing the number of magnetic processing frequencies) is the most
efficient technique, in a way that former technique causes an increase, in
comparison with the later technique, of 14.3% and 8.5% in the compressive
and tensile strength.
B) according to the results above, in the subject of tensile strength, water passing
through the magnetic field with the velocity of 1/6 of the base discharge is not
so cost-saving and caused a decline in the strength.
- The concrete containing 10% of Microsilica and a 0.5 water to cement ratio,
shows the best response to magnetizing and the compressive and tensile
strength, due to this change in the property of water (during six frequencies), the
amount of the increase in the compressive strength will be about 16.9% while
the concrete containing 10% of Microsilica and a 0.4 water to cement ratio has
the maximum increase (about 22.5%), due to six times of increasing the number
of the magnetic frequency, in the tensile strength. In case of magnetizing water
(with the velocity of 1/6 of the discharge), the concrete containing 10% of
Microsilica and a 0.5 water to cement ratio, shows the best response to the
magnetizing in the compressive and tensile strength and due to this change in
the property of water (during water passing will 1/6 of the base passing
discharge), the amount of the increase in the compressive and tensile strength
will be 26% and 37.9% respectively. Therefore, with a decrease in the
percentage of Microsilica and an increase in the water to cement ratio, the
concrete will have the maximum increase in the mechanical properties.
998 / The Study of Velocity and Frequency of Passing….
––––––––––––––––––
REFERENCES
1. H. Lotfi, “Effect of magnetic water on mechanical properties of lightweight
concrete, master thesis, Sistan and Baluchestan university, 2007” 8-10;
2. Y. Salimpoor, “Effect of decline rigidity and sediment of water with
electronically environment in heat and cold temperature, master thesis, Amir
Kabir university, 2006” 12-14;
3. Khash factory, “First congress about recognition and consumption of cement
types in cement factories, Khash, Sistan and Baluchestan, 2007”
4. A. Same, “ Quality and mix designing of concrete, Technical University of
Isfahan, 2006”, 44-54;
5. M. Shahnazari, M. Sahab, “Recipes of concrete laboratory, Iran University Of
Science & Technology, 2007,” 50-55;