DOĞAL ZEOLİT VE UÇUCU KÜL KATKILI VE KATKISIZ HARÇLARIN SÜLFAT DAYANIKLILIĞI

Puzolanik özelliği deneysel olarak belirlenen doğal zeolitin ve uçucu külün sülfata karşı dayanıklılığını araştırmak için % 5 ve % 10 ‘luk sodyum sülfat çözeltileri kullanılmıştır. Deneyler standart harçlarda ve çimento ağırlığının % 20 ve % 30 oranlarında ikameli olarak doğal zeolit , % 15 zeolit + % 5 uçucu kül ve % 25 zeolit + % 5 uçucu kül katılmış harçlarda yapılmıştır. Nümuneler 28 gün kirece doygun suda saklanmış ve 28. gün eskitme süreci için başlangıç kabul edilmiştir. Başlangıçta 2, 7, 28, 90. günlerde nümunelerde eğilme dayanımı, basınç dayanımı ve birim ağırlık belirlenmiştir. Çözeltiler 14 gün ara ile yenilenmiş ve bu periyotlarda ağırlıklar ölçülmüştür. Sodyum sülfat çözeltilerinin harç özelliklerine etkileri zeolit oranına göre değerlendirilmiştir. Çimentoya zeolit katılması 90. güne kadar yüksek konsantrasyonda bile harcın sülfata karşı dayanıklılığına olumlu etki yapmıştır.

SULFATE DURABILITY OF MORTARS PRODUCED WITH AND WITHOUT NATURAL ZEOLITE AND FLY ASH

An investigation was carried out on the effect of sodium sulfate on the sulfate durability of mortars produced with natural zeolite and fly ash having puzzolanic character. Experiments were carried out on the Rilem portland cement standart mortars and cement – natural zeoılite mortars where the zeolite replaced 20 %, 30 %, 15 % zeolit + 5 % fly ash and 25 % + 5 % fly ash of the cement by weight. Sodyum sulfate concentrations were 5 % and 10 %. Sulfate exposures of mortars were initiated after 28 days of lime saturated water curing. Flexural strength, compressive strength and density were determined at the beginning of exposure and at the 2, 7, 28, 90th days. Water and solutions were renewed after each period of experimental time which was 14 days. Mass changes were determined at the time of renewing the solutions. The effects of sodium sulfate solutions on the properties of mortars were related to the zeolite ratio. Zeolite replacement caused significant increase in sulfate durability of mortars even at the highest sulfate concentration up to 90 days of exposure.

___

  • [1] K. Sarıiz, İ. Nuhoğlu, “Endüstriyel Hammadde Yatakları ve Madenciliği”, Anadolu Üniversitesi. Yayın No:636, Eskişehir, 1992.
  • [2] E. Erdem, R. Donat, H. Çetişli, “Hydration and Mechanical Properties of Cement Containing Zeolite”. Cement and Concrete World , No:17, 22-28, Ankara, 1999.
  • [3] P. K. Mehta, “Efects of Fly Ash Composition on Sulfate Resistance of Cement”. ACI Journal, V. 83, 994-1000, 1986.
  • [4] P. S. Mangat and J. M. El-Khatip, “Influence of Initial Curing on Sulfate Resistance of Blended Cement and Concrete”. Cem. Concr. Res. V. 22, 1089- 1100, 1992.
  • [5] R. D. Hooton, and J. J.Emery , “Sulfate Resistance of a Canadian Slag Cement”. ACI Materials Journa, 87, 547-555, 1990.
  • [6] P. J. Tikalsky and R. L. Carrasquillo, “Influence of Fly Ash on The Sulfate Resistance of Concrete”. ACI Materials Journa, 89, 69-75, 1993.
  • [7] E. F. Irassar, A. Di Maio, O. R.Batic ”Sulfate Attack on Concrete with Mineral Admixtures”. Cem. Concr. Res. Vol. 26, No. 1, pp. 113-123, 1996.
  • [8] H. Biricik, F. Aköz, “Sodyum Sülfat Çözeltisinin Buğday Sapı Külü Katkılı ve Katkısız Harçlara Etkisi”. Çimento ve Beton Dünyası, Yıl 5. Sayı 26 (11-17), Ağustos, 2000.
  • [9] A. M. Neville, “Properties of Concrete Pitman Publishing”, Singapore, 443-451,1990.
  • [10] M. D. Cohen, A. Bentur, “Durability of Portland Cement Silica Fume Pastes in Magnesium Sulfate and Sodium Sulfate Solutions”. ACI Journal, V. 5, N. 3, May-june, pp 148-157, 1988.
  • [11] O. A. Kayyali, “Porosity and Compressive Strength of Cement Paste in Sulfate Solution”. Cem. Concr. Res, V. 19, N. 3, pp.423-433, 1989.
  • [12] E. F. Irassar, “Sulfate Resistance of Blended Cement Prediction and Relation with Flexural Strength”. Cem. Concr. Res, V. 20, N. 2, pp.209-218, ,1990.
  • [13] E. A. Abdun-Nur, “Fly Ash in Concrete: An Evulation”, Highway Research Board Bulletin, No.28, 138 s, Washington D.C., 1961.
  • [14] M. Tokyay, K. Erdoğdu, “Uçucu Küllerin Karakterizasyonu”, TÇMB AR-GE/Y 98.3, Ağustos, 1998.
  • [15] F. Canpolat, K. Yılmaz, R. Ata and M. M. Kose, ”Prediction Ratio of Mineral Substitution in the Production of Low-Clinker Factored Cement by Artificial Neural Network”. Mathematical and Computational Applications, 8(2) , 209-218 2003.
  • [16] S.¸ Targan, A. Olgun, Y. Erdogan, V. Sevinc, “Influence of Natural Pozzolan, Colemanite Ore Waste, Bottom Ash and Fly Ash On The Properties Of Portland Cement”. Cem. Concr. Res. 2304, pp. 1–8, 2003 (In press).
  • [17] I. Kula, A. Olgun, V. Sevinc, Y. Erdogan, “An Investigation on The Use Of Tincal Ore Waste, Fly Ash and Coal Bottom Ash as Portland Cement Replacement Materials”, Cem. Concr. Res. V. 32. pp.227–232, 2002.
  • [18] F. Canpolat, K. Yılmaz and M. M. Kose, “Effects of Natural Zeolite and Fly Ash as Replacement Materials on The Properties of Portland Cement”, Energy, Education, Science and Technology, 10 (1), 41-48, 2002.
  • [19] A. Demirbas, A. Aslan, “Evaluation of Lignite Combustion Residues as Cement Additives”, Cem. Concr. Res. V. 29, pp. 983-987, 1999.
  • [20] D. Bonen, “A Microstractural Study of the Effect Produced by Magnesium Sulfate on Plain and Silica - Fume Bearing Portland Cement”. Cem. Concr. Res, V. 23, N.3, pp.541-553, 1993.
  • [21] P. K. Mehta, O. D. Gjorv, ”Properties of Portland Cement Concrete Containing Fly Ash and Condensed Silica – Fume”. Cem. Concr. Res, V. 12, pp.587-595, 1982.
  • [22] D. G. Montgomery, D. C. Hughes and R. I. T. Willaiams, “Fly Ash in Concrete: A Microstructural Study”, Cem. Concr. Res. V. 11 , pp.591-603, 1981.
  • [23] E. E. Berry, “Beneficiated Fly Ash: Hydration, Microstructure and Strength Development in Portland Cement Systems”, Proceeding of 3rd International Congress on Fly Ash, Silica Fume, Slag and Natural Pozzolans in Concrete, ACI Special Publication 114, Vol.1, pp. 241-273, Troudheim, 1989.
  • [24] F. Massazza, “Microstructure of Hydrated Pozzolanic Cements”, 1st International Workshop on Hydration and Setting, Dijon, 1991, London E&FN Spon, 1992.
  • [25] T. Y. Erdoğan, “Betonu Oluşturan Malzemeler-Çimentolar”, Türkiye Hazır Beton Birliği, İstanbul, 1995.