Abstract: Grain-size analysis is widely used to determine the particle size distribution (PSD) of materials in civil engineering, water conservancy and hydropower, and mining. However, there is limited information on the reasonable sample mass of super large-size fillers commonly used in engineering. Based on the theory of stratified sampling, a theoretical formula was established to obtain the sample capacity. A general method for determining the sample mass in the sieving test was proposed by considering the relationship between the average particle size of granular materials and its particle size distribution. Targeted tests were carried out to study the distributions of different gradations, and the reliability of the method was validated. The method was applied to determine the particle size distribution of the fillers used in Chongqing Jiangbei airport and Guizhou Longdongbao airport. Therefore, the proposed method provides references for the development and improvement of relevant engineering practices and specifications.

Key words: particle size distribution, grain-size analysis, stratified sampling, large particle size