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

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.

Numune Boyutunun CH Kilinin Donma-Çözülme Üzerindeki Etkisi

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 -20oC çözülme sıcaklığı +25oC 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.

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