Unconfined compressive strength and micro-structural properties of cemented sand and gravel materials

Abstract

The purpose of this study is to provide basic information for the utilization of theenvironmentally-friendly and economically outstanding CSG (cemented sand andgravel) construction method, which includes the physical and mechanical properties of CSG materials, such as the unconfined compressive strength, themicroscopic structure and the freezing and thawing resistance given the volume and curing time of the CGS and the size of the specimen. In this study, specimens with four different cement contents of 4, 6, 8 and 10% of the total weight and three different sizes of φ50×100 mm, φ100×200 mm and φ150×300 mm were prepared to examine the characteristics of the sizes of the specimens and the features including the compressive strength, microscopic structure, freezing- thawingresistance and degree of wet-dry resistance. The results show that the larger the size of the specimen and the greater the content of cement in the specimen, the higher the compressive strength, freezing-thawing resistance, and wet-dry resistance. Moreover, the reactive products for each size of specimen wereexamined, and it was observed that some typical needle structured ettringite was generated due to the blending of cement through microscopic structural analysis,such as SEM and EDS analyses. Key words: Cemented sand and gravel, unconfined compressive strength, freezing and thawing, SEM, micro structure.