**4. Concluding Remarks and Future Trends**

Geotextiles have proven to be classic, as well as high-performance, modern materials. They are successfully applied in geotechnical and civil engineering, in both developed and emerging countries, and the global demand is growing. On a historical scale, there is a certain cyclicity regarding the nature of the fibers used as geotextiles. In antiquity, natural fibers have been used for soil and road stabilization. Modern times have promoted synthetic fibers for geotextiles. Nowadays, the need to reduce the environmental impact of polymer waste has brought back to attention the natural fibers-based geotextiles.

Natural geotextiles respond to societal concerns about the environment by reducing the pollution. Used in short- and medium-term applications, natural geotextiles can replace geosynthetics up to a certain point and are recommended for controlling the soil erosion and in agriculture, for slopes and riverbank stabilization, and in other applications where revegetation is highly desirable. Aside from their properties and low production cost, the local availability of natural fibers is another advantage. Still, their limitation resides in their main feature—biodegradability—but their service life can be prolonged by different strategies, such as modification of natural fibers through various methods or the use of hybrid fibers.

Geosynthetics have superior properties, owing to the synthetic fibers they are made of, and a wider range of applications. Their performance can be further improved using additives during polymer processing or in post-processing stages, or by including the raw polymers in composite formulations along with other reinforcing components (clay microand nanoparticles, carbon nanotubes, graphene and graphene oxide particles, carbon fibers, basalt fibers).

The knowledge-based development of technical textiles opens new perspectives for geotextiles. For example, intelligent geotextiles used to stabilize railway infrastructure, dams, embankments or slopes incorporate sensors and are able to sense and monitor mechanical deformations, variation of temperature, humidity and pressure. Thus, they can be used for the early detection of structural failure and its location, which is a major advantage as it allows damage control and timely repairs. However, advances are constantly reported, which proves geotextiles remain an active field of research.

**Author Contributions:** Conceptualization, C.-A.T. and F.T.; methodology, C.-A.T. and F.T.; resources, F.T., M.N., M.-E.I., and C.-A.T.; writing—original draft preparation, F.T., M.N., M.-E.I., and C.-A.T.; writing—review and editing, F.T. and C.-A.T.; visualization, F.T. and C.-A.T.; supervision, F.T. and C.-A.T. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research received no external funding.

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Not applicable.

**Conflicts of Interest:** The authors declare no conflict of interest.

#### **References**

