PFI-RP: Novel coated geotextile to enhance water drainage from soil

The broader impact/commercial potential of this Partnerships for Innovation-Research Partnerships (PFI-RP) project includes establishing a new technological platform and associated fundamental science allowing for the rational design of geotextiles (factory-made fabric products) that can drain water from soil with high transport efficiency. Geotextiles have been widely utilized in infrastructures including roads, railways, and airports to improve soil properties by serving functions of drainage, separation, filtration, and reinforcement. Recently, a wicking geotextile that possesses deep grooved fibers was demonstrated to be able to remove water from soils through evaporation at the edges exposed to air. However, its water removal capability becomes limited either by high humidity or by fine particles in the soil. To overcome these limitations, this project will apply a porous absorbent coating on a wicking geotextile that can generate higher suction of water, and attract, transport, and discharge water laterally to the edges. This project will provide a solution to difficult water-related infrastructure problems that may pose risks to the public and require significant funding for repair and maintenance. The proposed project will advance the knowledge of water absorption and transport behavior on an absorbent with tailored wettability. Application of an absorbent to a wicking geotextile will enhance its effectiveness in removing water from soils with fine particles. The technical hurdles to be addressed include: effectiveness and durability of the porous absorbent, application of the coating on geotextiles, interfacial behavior between absorbent and soil, survivability of the absorbent coating during geotextile installation in soil, and lateral water transport and discharge in/from the geotextile buried in soils. The specific research objectives are to: (1) manufacture an absorbent-coated geotextile; (2) evaluate the water drainage performance of the geotextile in soils; (3) gain insights into the controlling factors for the effectiveness of the geotextile in soils through numerical modeling; and (4) develop design methods to account for the benefits of the geotextile in roads. The results and insights obtained from the proposed work will serve as a cornerstone for geosynthetic applications that will enhance the water removal from soils by incorporating an absorbent with tailored solid-liquid interfacial wettability. The research outcomes will also allow for rational design of geotextile surfaces enabling absorbing and transporting water even in unsaturated soils. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.