EFFECT OF ASPECT RATIO ON THE FREEZING-THAWING OF A CH CLAY

Öz

The geotechnical properties of fine grained soils which depends on the variation of aspect ratio (ξ=length/diameter) exposed to freezing-thawing is not known clearly. The effect of aspect ratio on unconfined compression strength and freezing-thawing resistance of fine grained soils after 0, 5, 10, and 20 freezing-thawing cycles have been investigated in this study. The freezing-thawing test was conducted in an automatic freezing-thawing cabinet, the freezing and thawing temperatures of which were selected as -20°C and +25°C, respectively. The unconfined compression test was conducted in an unconfined compression testing apparatus, the loading ratio of which was 0.8 mm/min. These values were held constant throughout the test. Tests were conducted on cylindrical samples with different ξ (length/diameter) ratios prepared at standard Proctor energy. The test results indicated that, as ξ ratio decrease and the number of freezing-thawing cycles increase, unconfined compression strength decrease and freezing-thawing grain loss increase.

Anahtar Kelimeler

• Aspect ratio,CH clay,Freezing-thawing,Unconfined compression strength

Numune Boyutunun CH Kilinin Donma-Çözülme Üzerindeki Etkisi

Öz

Donma-çözülmeye maruz zeminlerin davranışı numune boyutuna (ξ=boy/çap) bağlı olarak nasıl değişeceği tam olarak bilinmemektedir. Bu çalışmada numune boyutunun ince daneli zeminlerde 0, 5, 10 ve 20 donma-çözülme çevrim sonrası serbest basınç mukavemeti ve donma-çözülme dayanımı üzerindeki etkisi araştırılmıştır. Donma-çözülme deneyi donma sıcaklığı -20^oC çözülme sıcaklığı +25^oC olan otomatik donma-çözülme kabininde, serbest basınç deneyi yükleme hızı 0.8 mm/dk olan serbest basınç deney aletinde yapılmıştır. Bu değerler deney sırasında sabit tutulmuştur. Deneyler standart proktor enerjisinde hazırlanmış farklı ξ (boy/çap) oranlarına sahip silindirik numuneler üzerinde yürütülmüştür. Deney sonuçlarından numunelerin ρ oranı ve donma-çözülme çevrim sayısının artmasıyla serbest basınç mukavemeti ile donma-çözülme dayanıklılığının azaldığı belirlenmiştir.

Anahtar Kelimeler

• Boy/çap oranı,CH kil,Donma-çözülme,Serbest basınç dayanımı

Kaynakça

1. Altun, S., Sezer, A., Erol, A., 2009, “The Effects of Additives and Curing Conditions on the Mechanical Behavior of a Silty Soil”, Cold Regions Science and Technology, Vol.56, No.2-3, pp. 135-140.
2. An, M., Zhang, L., Yı, Q., 2008, “Size Effect on Compressive Strength of Reactive Powder Concrete”, J. China Univ. Mining & Technology, Vol.18, pp. 279-282.
3. Andersland O.B., Ladanyi B., 2004, Frozen Ground Engineering, 2nd edn. USA. John Wiley & Sons.
4. ASTM D 2166, Standard Test Method for Unconfined Compressive Strength of Cohesive Soil, American Society for Testing and Materials, West Conshohocken, Pennsylvania, USA.
5. ASTM D 698-78, Fundamental Principles of Soil Compaction, American Society for Testing and Materials, West Conshohocken, Pennsylvania, USA.
6. Bello, A.A., 2011, “Analysis of Shear Strength of Compacted Lateritic Soils”, The Pacific Journal of Science and Technology, Vol.12 No.1, pp. 425-434.
7. Del Viso, J.R., Carmona, J.R., Ruiz, G., 2008, “Shape and Size Effects on the Compressive Strength of High-Strength Concrete”, Cement and Concrete Research, Vol.38, pp. 386-395.
8. Felekoğlu, B., Türkel, S., 2010, “Effects of Specimen Type and Dimensions on Compressive Strength of Concrete”, Gazi University Journal of Science, Vol.18, No.4, pp. 639-645.

9. Ghazavi, M., Roustaie, M., 2010, “The Influence of Freeze-thaw Cycles on the Unconfined Compressive Strength of Fiber-reinforced Clay”, Cold Regions Science and Technology, Vol.61, pp. 125-131.
10. Gök, G., 2010, Değişik Geometrideki Betonların Basınç Dayanımlarının Çeşitli Su/Çimento Oranlarina ve Çimento Miktarlarına Göre İncelenmesi, Yüksek lisans tezi, Çukurova Üniversitesi, Fen Bilimleri Ensititüsü, Adana.
11. Gullu, H., Hazirbaba, K., 2010, “Unconfined Compressive Strength and Post-Freeze-Thaw Behaviour of Fine-Grained Soils Treated with Geofiber and Synthetic Fluid”, Cold Regions Science and Technology, Vol.62, pp. 142-150.
12. Hassini, S., “Some Aspects of Landfill Design”, Mediterranean Conf on Environmental Geotechnology. Cesme, Turkey. Environmental Geotechnology, pp.137-144. 1992.
13. Hazirbaba, K., Gullu, H., 2010, “California Bearing Ratio Improvement and Freeze-Thaw Performance of Fine-Grained Soils Treated with Geofiber and Synthetic Fluid”, Cold Regions Science and Technology, Vol.63, pp. 50-60.
14. Hazirbaba, K., Zhang, Y., Hulsey, J.L., 2011, “Evaluation of Temperature and Freeze-Thaw Effects on Excess Pore Pressure Generation of Fine-Grained Soils”, Soil Dynamics and Earthquake Engineering, Vol.31, pp. 372-384.
15. Hoek, E., Brown, E.T, 1980. Underground Excavations in Rock (No. Monograph).
16. Kaczynski, R.R., “Scale Effect During Compressive Strength Tests of Rocks”, Proceedings of the Fifth International Congress, International Association of Engineering Geology, 20-25 October 1986, Buenos Aires, Argentina. Volumes 1, 2 And 3. Publication Of: Aa Balkema, 1986.
17. Koç, V., Şener, S., 2003, “Hafif ve Normal Betondan Yapılmış Çift Konsol Numunelerin Basınç Göçmesinde Boyut Etkisi”, Türkiye İnşaat Mühendisliği XVII. Teknik Kongre ve Sergisi, pp. 137-141.
18. Kvǽrnǿ, H.S., Ǿygarden. L., 2006, “The influence of Freeze-Thaw Cycles and Soil Moisture on Aggregate Stability of Three Soils in Norway”, Catena. Vol.67, pp. 175-182.
19. Liu, J., Wang, T., Tian, Y., 2010, “Experimental Study of The Dynamic Properties of Cement- and Lime- Modified Clay Soils Subjected to Freeze-Thaw Cycles”, Cold Regions Science and Technology, Vol.61, pp. 29-33.
20. Lu, J., Zhang, M., Zhang, X., Pei, W., Bi, J., 2018, “Experimental Study on the Freezing–thawing Deformation of a Silty Clay”, Cold Regions Science and Technology, Vol. 151, pp. 19-27.
21. Narsilio, G.A., Santamarina, J.C., 2008, “Terminal Densities”, Geotechnique, Vol.58, No.8, pp.669-674.
22. Qi, J., Wei, M., Song, C., 2008, “Influence of Freeze-Thaw on Engineering Properties of Silty Soil”, Cold Regions Science and Technology, Vol.53, pp. 397-404.
23. Sakamoto, R., Shogaki, T., “Effect of Specimen Size on Unconfined Compressive Strength Properties for Natural Clay Deposits”, Proceedings of the Thirteenth (2003) International Offshore and Polar Engineering Conference, May 25-30, 2003.
24. Swain, R., 1968, “Strength–Size Effects in Brittle Model Tests Simulating Underground Rock Fracture”, The Mining Engineer, Vol.88, pp. 211-214.
25. Taşpolat, L.T., Zorluer, İ., Koyuncu, H., 2006, “Effect of Waste Marble Powder on Freezing-Thawing of Impermeable Clay Liners”, Technical Research, Vol.2, pp. 11-16.
26. Toy, S., Yilmaz, S., Yilmaz, H., 2007, “Determination of Bioclimatic Comfort in Three Different Land Uses in the City of Erzurum Turkey”, Building and Environment, Vol.42, pp. 1315-1318.
27. Wang, D., Ma, W., Niu, Y.H., Chang, X., Wen, Z., 2007, “Effects of Cyclic Freezing and Thawing on Mechanical Properties of Qinghai–Tibet Clay”, Cold Regions Science and Technology, Vol. 48, pp. 34–43.
28. Wang, S., Yang, Z. J., Yang, P., 2017, “Structural Change and Volumetric Shrinkage of Clay Due to Freeze-thaw by 3D X-ray Computed Tomography”, Cold Regions Science and Technology, Vol. 138, pp. 108-116.
29. Wang, S., Yang, P., Yang, Z. J., 2018, “Characterization of Freeze–thaw Effects Within Clay by 3D X-ray Computed Tomography”, Cold Regions Science and Technology, Vol. 148, pp. 13-21.
30. Xu, J., Ren, J., Wang, Z., Wang, S., Yuan, J., 2018, “Strength Behaviors and Meso-structural Characters of Loess after Freeze-thaw”, Cold Regions Science and Technology, Vol. 148, pp. 104-120.
31. Yalçın, E., 2013, “Dowel Numunelerinde Boyut Etkisi”, Fırat Üniv. Mühendislik Bilimleri Dergisi. Vol.25, No.2, pp. 129-136.
32. Yarbaşı, N., Kalkan, E., Akbulut, S., 2007, “Modification of the Geotechnical Properties, as Influenced by Freeze-Thaw, of Granular Soils with Waste Additives”, Cold Regions Science and Technology. Vol.48, pp. 44-54.
33. Yavuz, H., Sari, D., Varol, M., “Mermer ve Travertenin Tek Eksenli Basınç Dayanımının Belirlenmesinde Boyut ve Şekil Etkisi”, Türkiye III. Mermer Sempozyumu, Bildiriler Kitabı, 209-217, 2001.
34. Yazıcı, Ş., Sezer, İ.G., 2007, “The Effect of Cylindrical Specimen Size on the Compressive Strength of Concrete”, Building and Environment, Vol.42, pp. 2417-2420.
35. Zaimoğlu, A.S., 2010, “Freezing-thawing Behaviour of Fine-Grained Soils Reinforced with Polypropylene Fibers”, Cold Regions Science and Technology, Vol.60, pp. 63-65.