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

Authors : Ali Rıza Uluata

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Publication Date : 2010-12-11

Article Type : Research

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.  
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