Determination of the transitional fines content of sand-non plastic fines mixtures

The transitional fines content is the boundary between fines-dominated and sand-dominated behaviour. Experimental and calculation methods for the determination of the transitional fines content of sand-non plastic fines mixtures are summarized based on former studies. Different methods have been applied to data from several published sources in order to make a comparison. The results indicate that the calculation methods, which use the property indices of the sand and fines, may not always predict the value of the transitional fines content observed in laboratory tests. These differences and their possible causes are discussed. The relative size of the fines and sand particles has been considered as a parameter which influences the value of the transitional fines content. The analysis indicates that when the ratio of large to small grain diameter is large enough, the value of the transitional fines content remains within a relatively small range.