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Effect of Silica Fume on Workability and Compressive Strength of OPC Concrete

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Silica fume is a by product resulting from the reduction of high – purity quartz with coal or coke and wood chips in an electric arc furnace during the production of silicon metal or silicon alloys. Silica fume is known to improve the mechanical characteristics of concrete. The principle physical effect of silica fume in concrete is that of filler, which because of its fineness can fit into space between cement grains in the same way that sand fills the space between particles of coarse aggregates and cement grains fill the space between sand grains. As for chemical reaction of silica fume, because of high surface area and high content of amorphous silica in silica fume, this highly active pozzolan reacts more quickly than ordinary pozzolans. The use of silica fume in concrete has engineering potential and economic advantage. This paper presents the results of an experimental investigations carried out to find the suitability of silica fume in production of concrete. It is observed that the optimum dose of silica fume is 5% (by weight), when used as part replacement of OPC. The silica fume inclusion increases the workability and strength of concrete considerably.
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J. Environ. Nanotechnol.
Volume 3, No.3 pp. 32-35
ISSN (Print): 2279-0748
ISSN (Online): 2319-5541
doi: 10.13074/jent.2014.09.143086
* Vikas Srivastava Tel.: +919415369170
E-mail: vikas_mes@rediffmail.com
Effect of Silica Fume on Workability and Compressive Strength of
OPC Concrete
Vikas Srivastava
1*
, Rakesh Kumar
2
, V. C. Agarwal
3
and P. K. Mehta
4
1
Civil Engg. Department, SHIATS (Formerly AAI-DU), Allahabad, India
2
Civil Engg. Department, MNNIT, Allahabad, India
3
Civil Engg. Department, SHIATS (Formerly AAI-DU), Allahabad, India
4
Civil Engg. Department, MNNIT, Allahabad, India
Received: 08.05.2014 Accepted: 19.08.2014
Abstract
Silica fume is a by product resulting from the reduction of high purity quartz with coal or coke
and wood chips in an electric arc furnace during the production of silicon metal or silicon alloys. Silica
fume is known to improve the mechanical characteristics of concrete. The principle physical effect of
silica fume in concrete is that of filler, which because of its fineness can fit into space between cement
grains in the same way that sand fills the space between particles of coarse aggregates and cement grains
fill the space between sand grains. As for chemical reaction of silica fume, because of high surface area
and high content of amorphous silica in silica fume, this highly active pozzolan reacts more quickly than
ordinary pozzolans. The use of silica fume in concrete has engineering potential and economic
advantage. This paper presents the results of an experimental investigations carried out to find the
suitability of silica fume in production of concrete. It is observed that the optimum dose of silica fume is
5% (by weight), when used as part replacement of OPC. The silica fume inclusion increases the
workability and strength of concrete considerably.
Keywords: Silica fume; pozzolan; compressive strength; OPC.
1. INTRODUCTION
By addition of some pozzolanic materials, the
various properties of concrerte viz, workability,
durability, strength, resistance to cracks and
permeability can be improved. Many modern concrete
mixes are modified with addition of admixtures,
which improve the microstructure as well as decrease
the calcium hydroxide concentration by consuming it
through a pozzolanic reaction. The subsequent
modification of the microstructure of cement
composites improves the mechanical properties,
durability and increases the service-life properties.
When fine pozzolana particles are dissipated in the
paste, they generate a large number of nucleation sites
for the precipitation of the hydration products.
Therefore, this mechanism makes paste more
homogeneous. This is due to the reaction between the
amorphous silica of the pozzolanic and calcium
hydroxide, produced during the cement hydration
reactions (Sabir et al., 2001, Antonovich and Goberis,
2003, Rojas and Cabrea, 2002).
In addition, the physical effect of the fine
grains allows dense packing within the cement and
reduces the wall effect in the transition zone between
the paste and aggregate. This weaker zone is
strengthened due to the higher bond development
between these two phases, improving the concrete
microstructure and properties. In general, the
pozzolanic effect depends not only on the pozzolanic
reaction, but also on the physical or filler effect of the
smaller particles in the mixture. Therefore, the
addition of pozzolans to OPC increases its mechanical
strength and durability as compared to the referral
paste, because of the interface reinforcement. The
physical action of the pozzolanas provides a denser,
more homogeneous and uniform paste. Silica fume is
a by product resulting from the reduction of high
purity quartz with coal or coke and wood chips in an
Vikas Srivastava et al. / J. Environ. Nanotechnol., Vol. 3(3), 32
-35, 2014
elec
tric arc furnace during the production of silicon
metal or silicon alloys. Silica fume is known to
improve both the mechanical characteristics and
durability of concrete. The principle physical effect of
silica fume in concrete is that of filler, which because
of its fineness can fit into space between cement
grains in the same way that sand fills the space
between particles of coarse aggregates and cement
grains fill the space between sand grains. As for
chemical reaction of silica fume, because of high
surface area and high content of amorphous silica in
silica fume, this highly active pozzolan reacts more
quickly than ordinary pozzolans.
The use of silica fume in concrete has
engineering potential and economic advantage. It is
reported by most researchers
(Gafoori and Hamidou,
2007, Yogendran et al., 1987, Khayat et al., 1997,
Ramakrishnan and Srinivasan, 1982, Bayasi, 1993)
that workability is reduced on silica fume inclusion
however Kadri and Dual reported increase in
workability on replacement of cement by silica fume.
It is also reported (Gafoori and Hamidou, 2007,
Yogendran, 1987, Khayat, 1997, Ramakrishnan and
Srinivasan, 1982, Kadri and Dual, 1998) that
compressive strength is increased upto optimum
replacement level of silica fume. Strength of silica
fume concrete is affected by several factors viz. type
of cement, quality and proportion of silica fume and
curing temperature. The main contribution of silica
fume to concrete strength development at normal
curing temperature takes place from about 3 to 28
days. The contribution of silica fume to strength
development after 28 days is minimal (Sakr, 2006).
Bhanja and Sengupta (2003) reported that
inclusion of silica fume in the range of 5 25%
increases compressive strength in the range of 6.25
29.85% for water cement ratio between 0.26 - 0.42.
Sakr, 2006 reported that at 15% silica fume content
gravel concrete, barite concrete and ilmenite concrete
showed increased compressive strength by 23.33%,
23.07% and 23.52% respectively at 7 days, 21.34%,
20% and 22.58% respectively at 28 days, 16.5%,
18.7% and 22% respectively at 56 days and 18%,
7.14% and 22.80% respectively at 90 days.Dual and
Kadri (1998) reported that at 10% replacement level
compressive strength increased in the range of about
10 17 % at different water cement ratio(0.25-0.45).
Khayat et al (1997) reported that at 7.5% replacement
level compressive strength increased in the range of
about 10 17 % at different water cement ratio (w/c).
Babu and Prakash (1995)
reported that concrete with
silica fume even upto 40% replacement show strength
higher than that of the control concrete. The
improvements in strength at the different percentages
of replacement of replacement at any water cement
ratio were also varying over a wide range. Khan and
Ayers (1995)
reported 67% increase in compressive
strength at 10% replacement level and 0.38 w/c.
Cong et. al(1992) reported that concrete
containing silica fume as a partial replacement of
cement exhibits an increased compressive strength in
large part because of the improved strength of its
cement paste constituent. Slaniska and Lamacska
(1991) reported that at different replacement level of
cement by silica fume (3.75 10.25%) increase in
compressive strength in the range of about 12% - 57%
is observed. Detwiler and Mehta (1989) reported that
silica fume concrete showed improved compressive
strength in the range of 11.56% - 18.89%than the
conventional concrete at different water cement ratio.
In the present study an experimental
programme was conducted to investigate the
suitability of silica fume as partial replacement of
cement and its effect on the compressive strength and
workability of concrete. The referral concrete M
25
was made using 43 grade OPC (Birla) and the other
mixes were prepared by replacing part of OPC with
silica fume. The replacement levels were 5%, 10%,
15%, 20%, 25% and 30% (by weight). This paper
presents the results of this investigation.
2. MATERIAL AND METHODS
For the present investigation, the coarse
aggregate of size 12.5 mm and down from Bharatkup
quarry was used. The sieve analysis of the aggregates
was carried out and the same distribution / FM was
maintained throughout the experiment. The important
properties of the coarse aggregate were: Fineness
Modulus = 6.29; Flakiness index = 20% (< 40% Ok
BS 882-1992); Elongation Index = 7%; Moisture
content = 0.52% (<2% Ok); Crushing value = 18.2%
(<30 Ok); Specific gravity = 2.72 (2.6-2.8).
The fine aggregate used in the investigation
was ‘Jamuna’ sand. The properties of fine aggregate
found as per IS-383 were: Fineness Modulus = 2.5;
Moisture content = 0.52% (<2% Ok); Specific gravity
= 2.54. The gradation of fine aggregate (Zone III) was
maintained throughout the experiment.
Silica fume for the present investigation was
obtained from M/s ELCOM Enterprises, Mumbai. The
silica fume was sieved and the fraction passing 10
IS sieve was used in the experiments. The physical
and chemical properties of silica fume viz-a-viz, OPC
are presented in table 1. The binder used in the present
investigation was 43 grade OPC (Birla). The
properties of cement were determined in accordance
with IS 8112: 1989 were: Fineness = 6.8% (<10%
33
Vikas Srivastava et al. / J. Environ. Nanotechnol., Vol. 3(3), 32-35, 2014
Ok); Consistency = 31%; Initial Setting Time = 60
minutes (>30 minutes Ok) ; Final Setting Time = 480
minute (<600 minutes Ok).
Table 1. Physical and Chemical Properties of Silica
Fume
Properties
OPC
Silica
Fume
Physical
Specific gravity
3.1
2.2
Mean grain size
(μm)
22.5
0.15
Specific area
cm
2
/gm
3250
150000-
300000
Colour
Dark
Grey
Light to
Dark
Grey
Chemical compositions (%)
Silicon dioxide
(SiO
2
)
20.25
85
Aluminium oxide
(Al
2
O
3
)
5.04
1.12
Iron oxide (Fe
2
O
3
)
3.16
1.46
Calcium oxide
(CaO)
63.61
0.2-0.8
Magnesium oxide
(MgO)
4.56
0.2-0.8
Sodium oxide
(Na
2
O)
0.08
0.5-1.2
Potassium oxide
(K
2
O)
0.51
Loss on ignition
3.12
<6.0
For the present investigation, mix design for
M
25
grade of concrete (Target strength = 31.6 MPa)
was carried out using the above coarse aggregate, fine
aggregate, and the binder. The proportion of the
materials by weight was 1:1.89:2.17:0.48 (Cement:
Fine aggregate: Coarse aggregate: Water). To
investigate the effect of silica fume inclusion (as part
replacement of cement), 100 mm cubes were cast for
referral and other mixes having variable silica fume
content. The cement was replaced by silica fume at the
rate of 5, 10, 15, 20, 25, 30 and 35% (by weight). The
workability (Slump value) and the compressive
strength of different mixes were tested at 7 and 28
days as per the procedure laid down in IS: 516 - 1981.
The results obtained from the above investigation are
presented below.
3. RESULTS
The compressive strength of the cubes at
different ages and different silica fume content are
presented in Fig - 1. The slump values and compaction
factor of the different mixes are presented in table - 2.
Table 2. Variation of Slump and Compaction
Factor of different Mixes
Replacement
level (%)
Compaction
Factor
0 (Referral)
25
0.81
5
28
0.82
10
30
0.83
15
30
0.83
20
32
0.84
25
34
0.85
30
37
0.86
35
42
0.87
Fig 1 reveals that optimum replacement level
of cement by silica fume is 5%. At 5% replacement
level the strength of silica fume concrete improved by
12.5% and 18.18% at 7 days and 28 days respectively
as compared to the referral concrete. At all other
replacement levels the strength of silica fume concrete
is lower than the referral concrete, however, the
workability is marginally improved at all replacement
levels. It is reported in the literature that inclusion of
silica fume (5 40%) increases the strength in the
range of 6.25 67%. In our research work in which
silica fume was included between 5 35%, the
increase in strength is observed by 18.18%. The
strength improvement due to silica fume incorporation
in concrete occurs due to chemical and physical
processes, the chemical effect due to the pozzolanic
activity and the physical effect due to the microfiller
action. However, decrease in strength is due to the
reason that silica fume added in excess of that required
for pozzolanic and filler actions results in replacement
of primary binder, that is cement, and hence reduction
in strength.
Fig. 1: Variation of compressive strength with
replacement level of OPC by silica fume.
0
5
10
15
20
25
30
35
40
45
0 5 10 15 20 25 30 35
R e pla c e m e nt L evel (%)
C om pres s ive S treng th (MP a)
7 D ays
28 Days
34
Vikas Srivastava et al. / J. Environ. Nanotechnol., Vol. 3(3), 32
-35, 2014
4
. CONCLUSIONS
The following conclusions are derived on the
use of silica fume in concrete making.
1. The optimum replacement level of
cement by silica fume is found to be 5%
by weight.
2. There is a significant improvement in the
compressive strength of concrete using
silica fume at both 7 and 28 days as
compared to the referral concrete.
3. The workability in case of silica fume
concrete is marginally improved.
4. Beyond optimum silica fume level the
strength decreases but the workability
increases.
ACKNOWLEDGEMENT
Authors of this paper express their sincere
appreciation to the M/s Elkem Enterprises, Mumbai
and Mr. S. Singh of MNNIT, Allahabad for his
support.
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Within the scope of the thesis, an experimental study was conducted to evaluate the performance of fly ash-based geopolymer concrete (GPC) piles, taking into account different environmental conditions. To obtain GPC concrete, sodium hydroxide (NaOH) and sodium silicate (Na2SiO3) were used together as an alkaline liquid. F class fly ash - blast furnace slag and C class fly ash - silica fume additives were used together in the preliminary experiments to obtain GPC concrete prepared using natural sand and natural crushed stone. The molarity of the mixtures was chosen between 10-16M in the experiments. According to the preliminary test results, C-class fly ash and silica fume were used in the formation of GPC concretes within the scope of the study. Using L16 Taguchi design, different parameters (Molarity (M), Alkaline activator solution/binder ratio (AA/B), Na2SiO3/NaOH ratio (SS/SH), Aggregate rate ratio in the mixture (G), and Water / Geopolymer solid ratio (Water/GK) and levels by preparing small-scale geopolymer (KKÖ) samples; Uniaxial compressive test, flexural strength test, freeze-thaw cycles, and compressive strength tests were performed on the samples exposed to salt resistance. The same experiments were carried out on large-scale geopolymer (BKÖ) samples for suitable designs and optimum design. Pile loading tests were carried out on GPC piles and cement-based model test piles (55mm diameter, 400-600m length) were prepared for optimum design. In addition, SEM and XRD analyses were performed for the samples taken. According to the experimental study results, the highest strengths were obtained for the L1 design, and the smallest strengths were obtained for the L13 design in the KKÖ samples. The compressive strengths of the KKÖ samples in the L1 design and the BKÖ samples in the L13 design were found to be higher. Geopolymer samples gained early strength due to the calcium (Ca) content since C-class fly ash was used within the scope of the study. According to the uniaxial compressive strength tests performed on KKÖ samples, the most effective factor on the compressive strength was the Water / GK ratio. According to the results of S/N analysis; As the water/GK ratio and the molarity increase, the strength decreases. Max. Optimum levels for compressive strength were found water/GK=0.35, M=10, AA/B=0.40, SS/SH=2.0, and G=0.70. 7 and 28 days uniaxial compressive strengths of 25.85 MPa and 28.61 MPa were obtained in BKÖ samples (Lopt) prepared for optimum design, which show that piles with strengths close to cement-based concrete can be produced. The most effective parameter of flexural strength was Molarity. According to the results of the S/N analysis; max. optimum levels for compressive strength were M=12, AA/B=0.40, SS/SH=1.75, G=0.60, and Water/GK=0.35. While the high-strength samples were exposed to freeze-thaw cycles, the strength loss was low, but the low-strength samples in the cyclic condition had a high-strength loss after the freeze-thaw cycle. In general, the resistance and stability of GPC concrete samples against the freeze-thaw effect are high, which is associated with the reduction of micropores by silica fume in the structure of the geopolymer. The most effective parameter on the strengths after freeze-thaw cycles was the Water/GK ratio. According to the results of the S/N analysis; max. Optimum levels for compressive strength are Water/GK=0.35, AA/B=0.40, M=10, SS/SH=2.25, and G=0.60. BKÖ geopolymer samples remained more stable than KKÖ samples in terms of both strength and mass loss under the effect of freeze-thaw cycles. For the L13 design, which did not provide sufficient performance in KKÖ samples, sufficient performance was provided in BKÖ samples. Mass losses in KKÖ geopolymer samples exposed to salt attack with 5% NaCl solution vary between 3.2-5.3%. In some of the samples exposed to salt attack, strength loss and some increase in strength were observed. While the most effective parameter on GPC concrete strengths under salt attack was the SS/SH ratio. According to the results of the S/N analysis; max. Optimum levels for compressive strength were obtained as SS/SH=1.75, M=10, AA/B=0.40, Water/GK=0.35, and G=0.70. Mass losses in BKO geopolymer samples remained insignificant. The images obtained in the SEM analyses showed that as a result of the complete reactions between alkaline solutions and fly ash, a compact and dense matrix structure was observed in GPC concrete in most designs (L1, L2, L15, and Lopt), and the images were in the direction of confirming the uniaxial compressive strength results. XRD diffraction patterns are important in that they indicate that the Ca component in Class C fly ash is important in the geopolymerization process and that Gismondine (C-A-S-H) and Calcium Silicate Hydrates (C-S-H) are formed at low Water/GK ratios. In the pile loading tests carried out on 2 pieces of GPC concrete with diameters of D=55 mm, lengths of L=400 mm and L=600 mm, and 2 pieces of cement-based piles in a medium compact sand soil prepared with relative density Dr = 50.28% in the tank; While the end bearing resistances were close to each other in both pile types, the environmental friction resistance of GPC concrete piles was higher. While the environmental friction resistance in GPC piles constituted approximately 40% of the total final bearing capacity, the environmental friction resistance in cement-based piles constituted approximately 30% of the total final bearing capacity. The ultimate bearing capacity of GPC piles has been obtained and it has been determined that they can be used as a good alternative to cement-based piles. With the thesis study, the high compressive strength of GPC concrete piles, their early strength gain, freeze-thaw cycles, and high resistance to salt resistance are important in terms of showing that this type of piles can be used especially in environments where adverse environmental conditions are effective.
Thesis
Tez çalışması kapsamında uçucu kül esaslı oluşturulan geopolimer beton (GPC) kazıkların performansının farklı çevresel koşulların da dikkate alınarak değerlendirilmesi amacıyla deneysel bir çalışma yürütülmüştür. GPC beton elde etmek için alkali sıvı olarak sodyum hidroksit (NaOH) ve sodyum silikat (Na2SiO3) birlikte kullanılmıştır. Doğal kum ve doğal kırmataş kullanılarak hazırlanan GPC beton elde edebilmek için yapılan ön deneylerde F sınıfı uçucu kül – yüksek fırın cürufu ve C sınıfı uçucu kül - silis dumanı katkıları birlikte kullanılmıştır. Deneylerde karışımların Molaritesi 10-16M arasında seçilmiştir. Ön deney sonuçlarına göre çalışma kapsamında GPC betonlarının oluşturulmasında C sınıfı uçucu kül ile silis dumanı kullanılmıştır. L16 Taguchi tasarımı kullanılarak farklı parametreler (Molarite (M), Alkali aktivatör çözeltisi / bağlayıcı oranı (AA/B), Na2SiO3/NaOH oranı (SS/SH), Karışımdaki agrega oranı (G) ve Su / Geopolimer katı oranı (Su/GK)) ve seviyeleri için küçük ölçekli geopolimer (KKÖ) numuneler hazırlanarak; Tek eksenli basınç deneyi, eğilme dayanımı deneyi, donma-çözülme çevrimleri ve tuz direncine maruz numuneler üzerinde basınç dayanım deneyleri uygulanmıştır. Uygun tasarımlar ve optimum tasarım için büyük ölçekli geopolimer (BKÖ) numuneler üzerinde de aynı deneyler gerçekleştirilmiştir. Optimum tasarım için hazırlanan GPC kazık ve çimento esaslı model deney kazıkları (55mm çaplı, 400-600m uzunluklu) üzerinde kazık yükleme deneyleri gerçekleştirilmiştir. Ayrıca alınan numuneler için SEM ve XRD analizleri gerçekleştirilmiştir. Deneysel çalışma sonuçlarına göre KKÖ numunelerinde en büyük dayanımlar L1 Nolu tasarım, en küçük dayanımlar L13 Nolu tasarım için elde edilmiştir. L1 Nolu tasarımda KKÖ numunelerin, L13 Nolu tasarımda BKÖ numunelerin basınç dayanımları fazla bulunmuştur. Çalışma kapsamında C sınıfı uçucu kül kullanıldığı için kalsiyum (Ca) içeriğinden dolayı Geopolimer numuneler erken dayanım kazanmıştır. KKÖ numuneler üzerinde yapılan Tek eksenli basınç dayanımı deneylerine göre dayanım üzerinde en etkili faktör Su / GK oranı olmuştur. S/N analizi sonuçlarına göre; Su/GK oranı ve Molarite arttıkça dayanım azalmaktadır. Max. dayanım için optimum seviyeler S/GK=0.35, M=10, AA/B = 0.40, SS/SH=2.0 ve G=0.70 bulunmuştur. Optimum tasarım için hazırlanan BKÖ numunelerinde (Lopt) 7 ve 28 günlük Tek eksenli basınç dayanımları 25.85 MPa ve 28.61 MPa elde edilmiştir ki, bu değerler çimento esaslı betona yakın dayanımlara sahip kazıkların üretilebileceğini göstermektedir. Eğilme dayanımı üzerinde en etkili parametre Molarite olmuştur. S/N analizi sonuçlarına göre; max. dayanım için optimum seviyeler M=12, AA/B=0.40, SS/SH=1.75, G=0.60 ve Su/GK=0.35 olmuştur. Yüksek dayanımlı numuneler donma – çözülme çevrimlerine maruz kaldıklarında dayanım kaybı az olurken, çevrimsiz durumda düşük dyanımlı numunelerde donma-çözülme çevrimi sonrasında da dayanım kaybı fazla olmuştur. Genel olarak GPC beton numunelerinin donma-çözülme etkisine karşı direnci ve stabilitesi yüksek olup, bu durum geopolimerin yapısındaki silis dumanının mikro gözenekleri azaltması ile ilişkilidir. Donma-çözülme çevrimleri sonrasında dayanımlar üzerinde en etkili parametre Su/GK oranı olmuştur. S/N analizi sonuçlarına göre; max. dayanım için optimum seviyeler Su/GK=0.35, AA/B=0.40, M=10, SS/SH=2.25 ve G=0.60 şeklindedir. BKÖ geopolimer numuneler donma-çözülme çevrimleri etkisi altında hem dayanım hem de kütle kaybı anlamında KKÖ numunelere göre daha stabil kalmıştır. KKÖ numunelerinde yeterli performansı sağlamayan L13 tasarımı için BKÖ numunelerde yeterli performans sağlanmıştır. %5 Nacl çözeltisi ile tuz saldırısına maruz bırakılan KKÖ geopolimer numunelerdeki kütle kayıpları %3.2-5.3 arasında değişmektedir. Tuz saldırısına maruz bırakılan numunelerin bir kısmında dayanım kaybı bir kısmında ise dayanımlarda artışlar gerçekleşmiştir. Tuz saldırısı altında GPC beton dayanımları üzerindeki en etkili parametre SS/SH oranı olurken,. S/N analizi sonuçlarına göre; max. dayanım için optimum seviyeler SS/SH=1.75, M=10, AA/B=0.40, Su/GK=0.35 ve G=0.70 olarak elde edilmiştir. BKÖ geopolimer numunelerinde kütle kayıpları önemsiz düzeyde kalmıştır. SEM analizlerinde elde edilen görüntüler alkali çözeltiler ve uçucu kül arasında tam olarak gerçekleşen reaksiyonlar sonucunda çoğu tasarımda (L1, L2, L15 ve Lopt) GPC betonda kompakt ve yoğun bir matris yapısı gözlendiğini ve görüntülerin Tek eksenli basınç dayanımı sonuçlarını doğrulayıcı yönde olduğunu göstermiştir. XRD kırınım desenleri, geopolimerizasyon sürecinde C sınıfı uçucu kül içerisindeki Ca bileşeninin önemli olduğunu ve düşük Su/GK oranlarında Gismondine (C-A-S-H) ve Kalsiyum Silikat Hidratların (C-S-H) oluştuğunu işaret etmesi açısından önemlidir. Tank içerisinde rölatif sıkılığı Dr = %50.28 olacak şekilde hazırlanmış orta sıkı kum zemin içerisinde çapları D=55 mm, uzunlukları L=400 mm ve L=600 mm olan 2 adet GPC beton ve 2 adet çimento esaslı kazık üzerinde yapılan kazık yükleme deneylerinde; her iki kazık türünde uç taşıma dirençleri birbirine yakınken, GPC beton kazıkların çevre sürtünme dirençleri daha yüksek elde edilmiştir. GPC kazıklarda çevresel sürtünme direnci toplam nihai taşıma gücünün yaklaşık %40’ını oluştururken, çimento esaslı kazıklarda çevresel sürtünme direnci toplam nihai taşıma gücünün yaklaşık %30’unu oluşturmuştur. GPC kazıkların nihai taşıma kapasitesi daha fazla elde edilmiş olup, çimento esaslı kazıklara iyi bir alternatif olarak kullanılabileceği belirlenmiştir. Tez çalışması ile GPC beton kazıkların basınç dayanımının yüksek olması, erken dayanım kazanmaları, donma-çözülme çevrimleri ve tuz direncine karşı göstermiş oldukları yüksek direnç özellikle olumsuz çevresel koşullarının etkili olduğu ortamlarda bu tip kazıkların kullanılabileceğini göstermesi açısından önemlidir.
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