Parameters Controlling Tensile and Compressive Strength of Fiber-Reinforced Cemented Soil

Enhancement of local soils with fibers and cement for the construction of stabilized pavement bases, canal lining, and support layers for shallow foundations shows great economical and environmental advantages, avoiding the use of borrow materials from elsewhere, in addition to the need of a spoil area. In previous studies, a unique dosage methodology for cemented soils has been established based on rational criteria in which the porosity-to-cement ratio plays a fundamental role in the assessment of the target unconfined compressive strength ($q_u$). The present paper extends previous work by quantifying the influence of the amount of cement, the porosity, and the porosity-to-cement ratio in an assessment on tensile strength ($q_t$) and compressive strength of a fiber-reinforced artificially cemented sand, in addition to the evaluation of the $q_t/q_u$ relationship. A program of splitting tensile tests and unconfined compression tests considering four distinct dry densities and five cement contents, varying from 1–7%, was carried out in the research reported in this paper. The results show that a power function adapts $q_t$ and $q_u$ values well with increasing cement content and reducing porosity of the compacted mixture. The porosity-to-cement ratio is an appropriate parameter to assess both tensile strength and unconfined compressive strength of the fiber-reinforced sand/cement mixture studied. Finally, the $q_t/q_u$ relationship is unique for the fiber-reinforced sand/cement studied, being independent of the porosity-to-cement ratio.