Volume change of expansive soils is a challenging issue, which affects various engineering structures all over the world. Consequently, we need environmentally-friendly and cost-effective soil stabilizers to address the challenges related to expansive soils. The utilization of natural fibers allows for the reduction in environmental impact since they are renewable and biodegradable raw materials. Moreover, the current article presents an experimental approach to study the effect of natural fibers on the mechanical behavior of expansive soils. Various experimental tests—such as Atterberg limits, standard compaction, direct shear, swelling potential, and swelling pressure—were conducted on control and treated soil samples using different percentages of fibers. The results of measurements of the physico-mechanical properties after reinforcement of the soil with 1%, 5%, and 10% of natural fibers indicate that the mechanical behavior of expansive soils is greatly influenced by the addition of natural fibers. To conclude, 86% reduction was observed in the swelling coefficient of treated soil. Future research can be done to check the durability of the current practice in detail.

This research focuses on the optimization of formulation, characterization, and damage analysis of plant fiber-reinforced polyester resin composites (jute and date palm). To better understand the characteristics and mechanical behavior of these materials, this study investigates the influence of resin content and plant fibers on the physico-mechanical behavior of the resin composites. Resinous composites consisting of polyester resin and raw earth were studied using a novel formulation based on an empirical method that follows the principle of earth saturation with polyester resin. Saturation was achieved with a 28% content of polyester resin, which appeared to be an optimal blend for the earth–resin composite. Plant fibers were randomly incorporated as reinforcement in the composites at various percentages (1%, 2%, and 3%) and lengths (0.5 cm, 1 cm, and 1.5 cm). Mechanical tests including bending, compression, and indentation were conducted to evaluate the mechanical properties of the composites. Analysis of fracture morphology revealed that the deformation and rupture mechanisms in bending, compression, and indentation of these composites differ from those of traditional concrete and cement mortar. The obtained results indicate that the composites exhibit acceptable performance and could be favorably employed in the rehabilitation of historic buildings.

The treatment and stabilization of soils make it possible to recycle materials on construction sites in preparation for the installation of a final covering or the construction of a road network. In road geotechnics, various materials such as lime, cement, and pozzolans were used as additions to stabilize clay soils. In recent years, bio-polymers and bacteria are of increasing interest to researchers in the field of stabilization and improvement of the physico-mechanical and chemical characteristics of clay soils. Currently, in place of traditional clay treatment techniques and to minimize environmental problems, natural fibrous waste is being used increasingly and spectacularly. Several studies on biotechnological engineering applications already exist, such as the use of vegetation, algae, bacteria, enzymes, and biopolymers. The northern Algerian region where the urban tissue does not stop expanding contains significant potential in terms of wheat straw, which represents a very present agricultural waste. So, there is a local interest in the sustainable development of several regions known to produce wheat. This study is interested in investigating the effect of wheat straw on the stabilization of swelling clay soil. In order to improve the physico-mechanical characteristics of clay soils, a series of laboratory tests (Atterberg limit, Proctor test, direct shear test, Oedometer test, and unconfident compressive strength test) were carried out on reconstituted clay soil with defined initial properties through numerous analyses (e.g., XRD and XRF) and then treated with different vegetable fiber content. The results indicate that there is an improvement in the compressibility characteristics of the treated soil, a remarkable decrease in the swelling index and the compressibility index respectively with increasing percentages of wheat straw.

Expansive soils sensitivity to volumetric change is one of the well-known challenges in the field of geotechnical engineering. Various attempts have been made by researchers to solve this problem. Current research presents the effect of human hair fibers on the behavior of expensive soils. A reconstituted soil of 80% kaolin as raw material and 20% bentonite with different percentages of human hair (0%, 0.5%, 1%, 1.5% and 2%) was used. The microstructure of the formulations was characterized by studying the interactions between soil and human hair using scanning electron microscopy (SEM). The microstructure of the formulations was characterized by studying the interactions between soil and human hair using scanning electron microscopy (SEM). Atterberg limits, compaction characteristics, swelling parameters, compressibility and shear strength were also examined. The results of this study indicate that the inclusion of human hair fibers significantly improves the properties of the expansive soil mixture. These results open up new prospects for the stabilization of expansive soils.

Purpose. To support and contribute to ecological and sustainable solutions, this paper aims to experimentally validate previous studies that proposed alternatives for improving soil characteristics using harmful waste. Methodology. This study investigates the incorporation of different percentages (2 %, 4 %, 6 %, and 8 %) of ground tire waste (GTW), powdered tire waste (PTW), and fibrous tire waste (FTW) into sandy soils (SS) to evaluate their effects on mechanical properties and particle density. Findings. The results indicate that the addition of tire waste consistently reduces both the density of soil solids and the maximum dry density due to the lower density of the tire materials compared to sand. The most pronounced reduction is observed with fibrous tire waste (FTW), resulting in a particle density of 2.19 t/m3 for the soil and a maximum dry density of 1.57 t/m3 at an 8 % incorporation rate, making these mixtures suitable for lightweight embankments. In terms of mechanical performance, GTW maintains high California Bearing Ratio (CBR) values, while PTW leads to a significant decline. Conversely, FTW enhances unconfined compressive strength (UCS) to 82 kPa, compared to 68.5 kPa for pure sand. Originality. The results of this study show the potential of tire waste in improving the mechanical properties and density of sandy soils, highlighting the importance of using waste in the field of geotechnics. Practical value. The findings reveal the potential of applying tire waste as an eco-friendly, sustainable, and cost-effective solution for infrastructure development.