Mechanical characteristics of soft clay treated with fibre and cement
ABSTRACT: In this study, the influence of three types of fibre – polypropylene, recycled carpet and steel – on the mechanical properties of cement-treated clay is investigated. Cement-treated clay specimens were prepared with cement contents of 5%, 10% and 15% by weight of dry soil, and cured for 14 days. To investigate and understand the influence of different fibre types and contents, three different percentages of fibre content were adopted. The results of unconfined compression tests on 90 cylindrical samples of cement-treated clay with varied cement and fibre contents are analysed to discern the relationships between these parameters and the key mechanical properties, including unconfined compressive strength and stiffness of treated soil. Furthermore, indirect tension test results of a further 90 treated soil samples have been used to determine the influence of fibre and cement content on the tensile strength of the treated soil. The fibre reinforcement increases the peak compressive strength. The a...
Fundamental Parameters of Cement-Admixed Clay—New Approach
The fundamental parameters such as after-curing void ratio (eot) and cement content (Aw) have been found sufficient to characterize the strength and compressibility of cement-admixed clay at high water contents. From analyses performed on the results of unconfined compression tests, the ratio eot/Aw has been proven to combine together the influences of clay water content, cement content, and curing time on the strength of cement-admixed clay. Moreover, the results of oedometer consolidation tests revealed that while Aw governs the position of the postyield compression line, the magnitude of eot determines the magnitude of the one-dimensional vertical yield stress σvy′ at particular Aw. The value of eot reflects, primarily, the clay water content and, secondarily, the cement content and the curing time. Normalizing the after-curing unit weight, after-curing water content, and after-curing specific gravity were incorporated in an empirical relationship of eot.
STRESS-STRAIN BEHAVIOR AND YIELDING CHARACTERISTICS OF EASTERN OSAKA CLAY
The aim of this paper is to study the geotechnical and/or mechanical behavior of sensitive Eastern Osaka clay using the test results of clay sampled in the Tsurumi district. For this paper, we have carried out a series of tests for sensitive clay sampled in the eastern Osaka, Japan. The unconfined compression tests, laboratory vane tests, oedometer tests, isotropic and anisotropic consolidation tests, and the isotropically and anisotropically consolidated undrained tests were carried out to clarify the strength-deformation characteristics and to determine the strain-rate effect and yielding characteristics. Undrained cyclic triaxial tests were also performed to obtain the effect of cyclic loading on the deformation. In addition, isotropically consolidated undrained tests for specimens trimmed with several different angles to the sedimentation plane and undrained torsional tests were conducted related to the initial structural anisotropy.