ERZURUM İLİ DOĞAL AGREGAT OCAKLARI AGREGATININ ve BU AGREGATLA İMAL EDİLEN BETONUN BAZI ÖZELLİKLERİ ÜZERİNDE BİR ARAŞTIRMA

Year 1972, Volume: 3 Issue: 3, - , 11.12.2010

Ali Rıza Uluata

Abstract

ÖZET

Bu araştırma Erzurum ili doğal agregat ocakları agregatının
ve bu agregatla imal edilen beotonun bazı özelliklerini saptamak
amacıyla yapılmıştır, Araştırmada, Erzurum ili doğal agregat ocaklarım
temsil edebilecek özelliğe sahip 19 doğal agregat ocağı incelenmiş
ve herbir agregat ocağından temin edilen agregat numuneleri
üzerinde çalışılmıştır, Neticede agregat numunelerinin doğal· granülometri
eğrileri çizilerek, incelik modülleri hesaplanmıştır, Bunlara
ilaveten agregat numunelerinin kiİ+silt miktarı, kil toprakları miktarı,
. organik madde miktarı, birim ağırlığı, özgül ağırlığı, hava tesikirlerine
karşı dayanıklılığı ve aşınma mukavemeti tayin edilmiŞtir, Deneflerle
elde edilen veriler standart limitlerle karşılaştırılarpk gerekli münakaşalardan
sonra tavsiyelerde bulunulmuştur, Agregat nunıuneleri ile
sabit dozaJda ağırlık esasına göre hazırlanan havasız ve havalı taze beton
nümıınelerinin birim ağı:/ığı ve hava yüzdesi, şertleşmiş beton numun~lerinin
ise absorpsiyon kapasitesi tayin edilmiştir. Sertleşmiş beton nümunelerinin
28 gün sonunda denemeye tabi tutulmasından; havalı beton
numunelerinin ortalama umukavetmetinin, havasız beton numunelerinin
ortalama mukavemetinden ~ 30 kadar fazlalık gö'sterdiği tespit edilmiştir,
Ayrıca havalı ve havasız beton numunelerinin 28 günlük basınç mukavemetleri
esas alındığında, donma-çözünme deneyi sonunda havalı ve
havasız beton numunelerinin ortalama mukavemetlerinin sırayla
~ 6,44 ve ~ 12.06 oranında azaldığı bulunmuştur.

A RESEARCH ON SOME PROPERTIES of AGGREGATES of NATURAL
AGGREGATE SOURCES of ERZURUM PROVINCE and THE CONCRETE MADE WITH THESE AGGREGATES

This research is conducated to
determine important properties of
aggregates obtained from the natural
aggregate sources of Erzurum province
and to find out &ome properties of
normal and air entrdined concrete pre
pared with these aggregates. As a
reı.ult of this study; properties of present
natural aggregates and concrete
prepared with them wou!d be known,
and it would be reached 1.0 a conclusion
about some technical properties of
concretes prepared with same aggregates
such as strength, absorption
and resistanee to freezing and thawing.
The samples of aggregates obtained
from the natural aggregate sourees of
Erzurum, eement, 'potable water, water
reducing admixture (WRDA)ı different
too1s, instruments a'nd mechines,
and freezers are used as researh materials
Among natural aggregate sources which
are formed in the stream beds in the
research area 29 of them are selected
as sourees to abtain the aggregates to
use as the. main matedal of the research.
A general knowledge was gained
about aggregate sources by observations
an~ surveys made in place. Sufficient
amount of (800-1000 kg;) mix aggregate
for experiments are picked from
every seleeted aggregate source. Methods
which are exp!ained in detaiı at proper
chapters such as sieve analysis, roodUıes
of'finenesş, the amount of c1ay -silt,
day lumps, organic matter, umt weight,
spe;cifici gravity, absorption capacity,
.resistanee to weathering, absrasion resistance
are used for the detennination of the properties of aggregate samples.
Computation of concrete mixture is
based on eweight pereentage; workabiütiy
of fresh concrete is determined
by slump and flow tests. The unit weight
of fresh concrete İs found by samplingo
Gravimetric method İs used to determine
.Ür content of conrete. The compressiye
strengths of hardened normal airentrained
concrete are found by using
hydrau1ic press. The modulus of elasticity
is ca1culated with the eqm1tion
of Ros Absorption is found by using
weight basis. Resistnance to freezingthawing
is determined by standart freezing
·thawing experiment.
As a generalized concJusion; the
the experimentaJ!y found properties of
the aggregate samp!es of the natural
aggregate sourees of Erzurum province
a9-d of the concrete prepared with
these aggregates, compared and discussed.
Tehe semlts can be summarized
as fol1owing :
1. Grading curves of studied
samp1cs of fine aggregates exeept 2,
sm samples of fine aggregates exeept
4,8,19,26,27 and 29 numbered samples
and coarse aggregates exeept 10, ll,
13, 18, 19 and 20 numbered samples are
in the specified 1imits of standart grading
curves. From dhe grading point of
wiew , aggregate, of those sourees are
approprlate for pteparation of eoncrete
which can be used for any purpose.
All of the aggregate samples but 4,
8, 24, 26 and 27 numbered samap1es
have fineness modulus within the
limits of advised values suggested by
researchers. Therefore fineness modulus
will not be a problem for preparation
of ronerete.
2. Cansidering the c1ay+silt or
the amount of fine material passing.
the no: 200 standart sieve; exeept 2,
ıo, 12, LS and 23 numbered fine aggregate
samples, every aggregate can be
used for concİetes. For the eonerete
which is subjected to the abrasion, only
aggregates of 3, 7, 14, 15, 20, 21, 22,
24, 25 and 26 numbered samples are
advised for use. All of the coarse aggregates
have smal amoun of c1ay+silt
which is in the accepted limit for
concrete preparation.
3. The amount of day lumps or
muddy matedals are not more than
sPecified amounts in 1, 3, 5, 6, 9,
ll, 13, 14,-15, 16, 17, 18, 19, 20, 21,
25, 26, 28 and 29 numbered fine aggregate
samples; but it is exeessivse in
the other fine agrgregate samples and
in aLL of the co'arsa aggregate samples.
4. Fine aggregate samples have
law organic matteı (impritues). For
this reason, there wiıı not be a problem
regarding impurities.
5. All of the fine aggregate samplç-s
but 14, 15, 22 and 26 numbered on~s
h.8.ve unit weight values c10se to suggesteçl.
fjgures by researchers. Unit
weight values of coarse aggregate are
sufficient to o"tain poreless and high
strength concrete. Compacted unit
weights of fjne and coarse aggrl."gate
samples expect number 14, 15, ·22
and 29 are lower than what researchers
advise for use in concrete.
6. Saturated surfaee -dry specific
gravity of fine and coarse aggregates are
close to the values which are deter-
mined by researcher Even tought
absarption capacities of both king of
aggregates are close to absorption
capacities ot same aggregates are
sc10se to absarption capacities
same aggregates reported by same
researeh; theyare lower than advised
figures. Therefore coneretes prepared
with these aggregates will have lower
resistanee to freezing and thawing.
7. Depending on sodium sulfate
tests; a large number_of aggregate
samples (except number 5, 6, 15, 20,
24 and 28 fine aggregate samples and
number 5, 6, 17, 19, 24, 25 and 28
eoarse aggregate samples) are not
durable.'
8. All of the samples of coarse
aggregates are subjected to the Los
Angales Abrasion tests. Depending
on the results, they can be used
making concrete. subject to abrasion.
9. Theoric a:ıd sampled unit weights
workabilities and the total volumes of
air proes of the prepared normal and
air entrained [resh eonerete (except
those prepared wİth no: 5, 6, 12, B,'
19, 24, 25, 27 and 28) are within the
limits given by the literature.
i O. Compressive stregth of the
air-entrained concrete shaws. 30 %
avarage increase over the 28 days
compressive strength of normal concrete.
Stregth of normal roncrete (in
non-reinforced concrate) and air-entrainned
concrete (in non-reinforced and
reinforeed) are very c10se to avarage
given by literaturs.
IL. Strength of the normal and
air entrained toncrete decreased
when' the were subjected to freezİngthawing
test. This decrease from the
28 days strength was avarage of 12.06
%for normal and avarage of 6.44 %
for air-entriined concrete. Decrease in
the modulus of elasticity respect to
the 28 days modulus of elsasticity was
7.3 %for normal and 3.4%for air-entri
air-entrained concrete. There fare air
entrained concrete-is advisable for this
region.
12. The methods which are preferred
and u~ed in this study can be used to
determine the properties of the
aggregates of any region, -and for the
properties_of concrete made with those
aggregates.

 

Keywords

-