On the Efficiency of the Rotary Crushing and Mixing Technique for Enhancing the Gradation Properties of Low-Quality Geomaterials

Providing a sustainable supply of good-quality soil materials is vital for reliable implementation of earthworks. However, ensuring a sustainable supply is of great difficulty in the present. Therefore, various techniques are deployed in practice, including mixing several types and gradations of soils or mixing with additives such as cement and quicklime. Among other methods, the Rotary Crushing and Mixing technique（RCM） was introduced as a reliable method to modify and control the gradation properties of granular materials2）. Through this study, the efficiency of the small type of the RCM series, which is commonly used in practice, is investigated experimentally to elaborate on the role of particle crushing in improving the gradation properties of soil materials. Furthermore, a simple method is proposed considering the single-particle strength for estimating the particle size distribution of a soil material improved using the RCM. The accuracy of the method and its validity were confirmed using several materials, aiming at enhancing the practical efficiency of particle size adjustment methods. © 2024 The Society of Materials Science, Japan.