Comparison of the Precision of Dry Sieve Analysis versus Wet Sieve Analysis for Some Selected Natural Clay Varieties
Clay is a specific soil type that composed with relatively finer particles usually less than 0.002mm according to most of standard definitions including the behaviours of cohesive and the clay particles may have different sizes less than 0.002mm and most of occasions the clay bulk is contaminated with some more coarse particles such as sand and silt even though those particles are comprised in a same deposit or a same massive body. Most of clay varieties are frequently condign in the advanced technological uses. Therefore, the investigation of the particle sizes of some of clay and categorization are important tasks in the selection of a clay type for some particular technological application. The well known methods for the grain size analysis are the wet sieve analysis and dry sieve analysis in order for cohesive soils and non-cohesive soils as usual. In the existing study, there were anticipated to compare the accuracy of dry sieve analysis results with the wet sieve analysis results of three different selected clay verities in Sri Lanka. As the experiential works those clay samples were separately analyzed using a sieve range of 2mm- 0.037mm and pan (<0.037mm) using dry sieve method. Also those clay types were wet sieve analyzed with respect to the sieve size of 0.075mm. According to dry sieve analysis results the finer portions (<0.075mm) were obtained as ~17%, ~6% and ~16% from clay 1, clay 2 and clay 3. The results of wet sieve analysis showed ~60%, ~37% and ~72% of finer portions (<0.075mm) in clay 1, clay 2 and clay 3 while the average grain sizes (D50) of them were 0.25mm, 0.27mm and 0.19mm. When comparing of those results the minimum deviation between wet sieve analysis result and dry sieve analysis result was found from clay 2 which is having maximum average grain size (D50) while the maximum deviation was observing from clay 3 which is having minimum average grain size (D50).