Millions of tonnes of bagasse are annually generated as waste from the sugar industry, the disposal of which poses a critical global challenge. To address this, the study explores the potential utilization of sugarcane bagasse fibers as a reinforcing material to sand, aiming to enhance its mechanical properties through laboratory investigations. Initially, the primary physical characteristics of both sand and bagasse fibers are examined using laboratory tests and scanning electron microscopy. Further, consolidated drained triaxial compression tests were carried out on sand specimens, with fiber contents varying from 0 to 2%. The investigations encompass the influence of fiber content, fiber length, and effective confining pressures on the strength parameters, dilation, and stiffness of reinforced sand. Upon shearing, the bagasse reinforced sands exhibited a strain-softening behavior at low fiber contents and a strain hardening behavior at higher fiber contents. Results indicate the beneficial utilization of bagasse fiber in enhancing the strength parameters, and reducing the residual strength loss of sand, sensitive to the effective confining stress. With increase in percentage of bagasse fiber, the dilation of sand was found to be decreasing. The inclusion of bagasse fibers also leads to a reduction in the initial and secant stiffness of the sand. Furthermore, as the length of fiber shortens at same percentage of fiber, the peak and critical angle of friction reduces. Based on the test results, a normalized model of the reinforced sand has been developed to capture the peak and residual states of the sand in correlation with different critical parameters.

The synergetic effects of alkaline red mud (RM) and sulfate-based phosphogypsum (PG) on the undrained triaxial behavior of cement-admixed clay were explored in this study. A series of isotropically consolidated undrained triaxial tests were performed on stabilized clay with respect to different admixed RM/PG proportions. The triaxial behavior of stabilized clay is presented in terms of a stress-pore pressure-strain relationship, failure mode, undrained deformation modulus, stress path, and failure envelope. Scanning electron microscopy (SEM) tests were conducted to survey microscopic evolution. The results showed that the brittleness of the specimen intensified with a high RM content, which was manifested by a predominant postpeak strength reduction. As the PG content increased, the strain-softening behavior weakened and gradually evolved into strain-hardening. The failure mode changed from local shear failure to the single cone failure and bulging failure correspondingly. The RM played a role in increasing soil cohesion, whereas PG contributed to a larger frictional angle at the postyield stage. Microscopic observations indicated that the alkali source from RM significantly promoted pozzolanic reactions and strengthened cementation bonds, which increased the peak strength, deformation modulus, and cohesion. In addition, the sulfate in PG contributed to ettringite generation among clay particles and clusters, resulting in a more ductile behavior and a larger frictional angle due to large clusters formed.

In this study, the mechanical and durability performance of clay soils reinforced with different proportions of Cherry Marble Powder (CMP) and non-woven geotextile configurations, both independently and in combination, is investigated in detail at both the macro and micro levels. The effectiveness of reinforcement in the stabilization of clay soils in cold climates has been evaluated by means of Gray Correlation Analysis (GCA). The results show that as the CMP ratio and the number of geotextiles increase, the peak strength of the soil increases, with higher CMP levels showing perfect plastic behavior and more geotextiles showing linear strain hardening, particularly in combination. Substantial strength reductions post-7th cycle ranged between 91.09 % and 103.38 % for 12 % CMP and 219.83 % and 270.42 % for three-layered geotextile groups. Cohesion increased by 59.76 % and 179.41 %, while the internal friction angles remained stable and decreased after F-T cycles, except with additives. Failure modes shifted with CMP content, F-T cycles and confining pressure. The transition was from strain hardening to strain softening, with increased shear fracture planes and brittleness. The energy absorption capacity (EAC) increased with the CMP ratio, with the geosynthetic reinforcement increasing the EAC by a factor of 1.5 before and after the F-T cycles. The combined use of CMP and geotextiles in soil stabilization improved the engineering properties in areas of frost, with the optimum gradation being three layers of geotextile and a CMP ratio of 12 %, which effectively mitigated the effects of the maximum F-T cycle.