Project Description:

Green construction material plays an important role in sustainable development. With the development of construction materials, biopolymers are gradually being used as a soil improvement additive in geotechnical engineering. Seaweed, also known as macroalgae, is a diverse group of marine autotrophs that thrive in coastal and offshore environments. While seaweed has traditionally been used in applications such as food, fertilizers, and pharmaceuticals in many cultures, its potential as a sustainable resource has garnered renewed attention worldwide. Seaweed was used as construction materials where act as nature fiber in some coastal areas. However, research work about seaweed’s polymer properties is limited. Most of the research related to the extracts of seaweed. This proposed project will use seaweed as natural polymer for polymer modified sandy soil to prevent bridge scouring.

The objective of this research is, therefore, to develop an eco-friendly and sustainable solution to increase the erosion resistance of sandy soil. Unconfined compression and tensile strength tests will be used to assess the soil strength of various seaweed percentage treatments. Triaxial testing will be used to analyze the shear stress characteristics of seaweed-treated sandy soil, such as cohesion and friction angle. Finally, a pocket erodometer test will be performed to investigate the erosion resistance capabilities of seaweed-treated sandy soils.

 _{Fig. 1 Stress-strain curve of seaweed-treated soil with different particle size.}

US DOT Priorities:

This proposed project aligns closely with the "Transformation" pillar of the US DOT Strategic Goals, particularly emphasizing "Design for the Future." By investing in purpose-driven research and innovation, it aims to address present challenges while also modernizing the transportation system for the future. This endeavor seeks to create a transportation network that caters to the needs of everyone both now and in the decades ahead. The PI, Kang Du’s research group will develop an eco-friendly and sustainable solution to increase the erosion resistance of sandy soil and investigate the bridge scour mitigation with seaweed as nature binding material. A series of experiments will be conducted to optimize the seaweed particle sizes and content. The mechanical behavior and erosion resistance of seaweed-treated soil samples will be evaluated. Standards might be developed in the future work.

Outputs:

The use of nature polymers to tackle geotechnical problems is an essential step toward the development of sustainable geotechnical systems. The proposed project is anticipated to yield several tangible outputs, including: 1. publication of scientific papers detailing the methodology, findings, and conclusions of the investigation in peer-reviewed journals. 2. compilation of experimental data concerning the effectiveness of seaweed-based materials in mitigating bridge scours. 3. documentation of protocols and procedures developed for laboratory experiments, encompassing material preparation, testing methodologies, and data analysis techniques. 4. recording of field test results and observations, providing insights into the real-world performance of seaweed-based scour mitigation techniques. 5. creation of educational materials, such as presentations, videos, or brochures, aimed at disseminating information about the use of seaweed for bridge scour mitigation. 6. presentation of findings at conferences, workshops, and seminars within the fields of civil engineering, environmental engineering, and infrastructure construction management.

Outcomes/Impacts:

The proposed project aims to address the issue of bridge scours. Seaweed, known for its binding properties and environmental sustainability, is being explored as a potential solution for mitigating bridge scours. Here are potential outcomes and impacts of the project:

1. The primary outcome of the project would ideally be a significant reduction in bridge scour through the application of seaweed-based materials 
2. By utilizing seaweed, the project promotes sustainability and reduces the ecological footprint of bridge construction and maintenance activities.
3. If successful, using seaweed as a binding material for scour mitigation could potentially offer cost savings compared to traditional methods
4. By stabilizing the sediment around bridge foundations, seaweed-based solutions could help prevent progressive scours, thereby extending the lifespan of bridges and reducing the need for frequent maintenance or repairs.
5. Beyond bridge scour mitigation, the project outcomes may have broader implications for erosion control in aquatic environments. 
6. Research findings and methodologies developed through the project could serve as a basis for further studies and innovations in scour mitigation and erosion control. 
7. The project offers opportunities for community engagement and education regarding the importance of sustainable infrastructure practices and environmental conservation. 
8. Successful implementation of seaweed-based scour mitigation techniques may influence policies and regulations related to bridge construction and environmental protection