Compressibility and small strain stiffness of kaolin clay mixed with varying amounts of sand

• Published in: KSCE journal of civil engineering Vol. 21; no. 6; pp. 2152 - 2161
• Main Authors: Choo, Hyunwook, Lee, Woojin, Lee, Changho
• Format: Journal Article
• Language: English
• Published: Seoul Korean Society of Civil Engineers 01.09.2017; Springer Nature B.V; 대한토목학회
• Subjects: Binary mixtures; Civil Engineering; Clay; Clay soils; Compressibility; Compression; Compression tests; Constraining; Engineering; Geotechnical Engineering; Geotechnical Engineering & Applied Earth Sciences; Industrial Pollution Prevention; Kaolin; Mechanical properties; Porosity; Sand; Sand & gravel; Shear modulus; Soil; Soil compressibility; Soil mechanics; Soil porosity; Soils; Stiffness; Void ratio; 토목공학; small strain stiffness; fines content; interfine void ratio; kaolin; compression index; sand-clay mixed soil
• ISSN: 1226-7988; 1976-3808
• DOI: 10.1007/s12205-016-1787-4

This experimental investigation quantifies the compressibility and small strain stiffness of kaolin clay mixed with varying amounts of sand particles. The theoretical background of binary mixtures, including critical and limiting fines contents, porosity of binary mixed soils, and the concept of interfine void ratio, were reviewed. In addition, modified oedometer tests were conducted to measure both the compression index ( C c ) and maximum shear modulus ( G max ) of sand-clay mixed soils. The results of this study demonstrate that the critical fines content (FC*) of tested mixed soils is less than 40% and the limiting fines content (FC L ) is around 80%; therefore, the C c and G max of tested mixed soils with fines content (FC) = 80% and 90% are entirely determined by the small particles, reflecting the applicability of the concept of interfine void ratio for mixed soils with FC > FCL. In contrast, the C c and G max of tested sand-clay mixed soils with FC = 40% and 60% can be captured by the concept of equivalent interfine void ratio with fitting parameter m = 0. Therefore, the mechanical behaviors of tested sand-clay mixed soils with FC* < FC < FC L are determined by both large and small particles.