The slide presents a title slide for a master's thesis proposal titled "Stabilization of Marl Soil Using One-Part Geopolymers and Fibers." It is authored by Abdirahman Jamal Ahmed.

Stabilization of Marl Soil Using One-Part Geopolymers and Fibers

MS Thesis Proposal by Abdirahman Jamal Ahmed

Source: MS Thesis Proposal

This slide's abstract highlights the challenges of stabilizing marl soil for sustainable construction and introduces an eco-friendly one-part geopolymer approach to address them. It also discusses reinforcing the soil with natural and PET fibers to boost durability, presenting it as a sustainable engineering solution that tackles environmental concerns.

Abstract

• Challenges in stabilizing marl soil for sustainable construction projects.
• Overview of eco-friendly one-part geopolymer stabilization approach.
• Reinforcement using natural and PET fibers for enhanced durability.
• Sustainable engineering solution addressing environmental concerns.

Marl soil's high plasticity and low shear strength create significant construction challenges, while traditional stabilization methods using cement or lime contribute to environmental issues from high carbon emissions. Geopolymer stabilization provides a sustainable alternative by improving strength and durability, and fiber reinforcement further boosts ductility while minimizing cracking in treated marl.

Introduction

• Marl soil exhibits high plasticity and low shear strength, posing construction challenges.
• Traditional stabilization with cement/lime raises environmental concerns due to high carbon emissions.
• Geopolymer stabilization offers sustainable improvement in geotechnical properties like strength and durability.
• Fiber reinforcement enhances ductility and reduces cracking in stabilized marl soil.

Traditional cement and lime stabilization methods for marl soil produce high CO2 emissions and fail to effectively improve its properties, highlighting the environmental drawbacks of these approaches. This motivates the exploration of greener geopolymer alternatives, combined with fiber enhancements, to boost soil performance while minimizing ecological impact.

Problem Statement

• High CO2 emissions from traditional cement and lime stabilization methods.
• Ineffectiveness of cement/lime on stabilizing marl soil properties.
• Motivation for greener geopolymer alternatives to reduce environmental impact.
• Need for fiber-enhanced solutions to improve marl soil performance.

The presentation agenda outlines key sections starting with an introduction to marl soil challenges and gaps in traditional stabilization methods, followed by research objectives focused on characterizing marl properties, developing one-part geopolymers, and evaluating effects of natural and PET fibers. It then covers a literature review on soil properties, geopolymer advantages, fiber benefits, and existing research deficiencies, concluding with the methodology, experimental setup, testing plan, expected outcomes, timeline, and references.

Presentation Agenda

1. Introduction and Problem Statement

Background on marl soil challenges and gaps in traditional stabilization methods.

2. Research Objectives

Characterize marl properties, develop one-part geopolymers, evaluate natural and PET fiber effects.

3. Literature Review and Gaps

Overview of soil properties, geopolymer advantages, fiber benefits, and research deficiencies.

4. Methodology and Expected Outcomes

Experimental setup, testing plan, anticipated improvements, timeline, and references. Source: Stabilization of Marl Soil Using One-Part Geopolymers and Fibers - MS Thesis Proposal by Abdirahman Jamal Ahmed

Marl soils, with their high clay content, display swell-shrink tendencies and low strength, while traditional stabilizers like cement and lime enhance properties but cause significant environmental harm through CO2 emissions and resource use. In contrast, one-part geopolymers provide eco-friendly benefits with low alkali levels and simple mixing, and fiber reinforcement boosts ductility, crack resistance, and tensile strength as a sustainable soil stabilization option.

Literature Review

Current research on marl soil stabilization reveals significant gaps, including limited studies on using one-part geopolymers and few explorations of combining geopolymer with fiber reinforcement. Additionally, there is a notable absence of comprehensive mechanical property analyses, detailed microstructural characterizations, and sufficient emphasis on sustainable alternatives to traditional cement and lime stabilizers.

Research Gaps

• Limited studies on marl soil stabilization with one-part geopolymers.
• Few investigations into combined geopolymer and fiber reinforcement.
• Lack of comprehensive mechanical property analyses.
• Absence of detailed microstructural characterizations.
• Insufficient focus on sustainable alternatives to cement/lime.

The slide's left column details the materials and preparation for geopolymer-stabilized marl soil, including locally collected marl, precursors like fly ash and slag with alkali activators, natural sisal and recycled PET fibers at 0.5-2% dosages, and curing under ambient (25°C) or accelerated (60°C) conditions for 7-28 days. The right column outlines testing and evaluation methods, such as unconfined compressive strength for peak strength, California Bearing Ratio for subgrade suitability, direct shear for interface friction, and SEM/XRD for microstructure and phase analysis, conducted across multiple curing periods.

Methodology

The slide outlines expected outcomes of a stabilization technique for marl, including enhanced unconfined compressive strength (UCS) and California Bearing Ratio (CBR) values via geopolymer stabilization, along with improved ductility from natural and PET fiber reinforcement. It also highlights a reduced environmental footprint compared to traditional cement or lime methods, enabling sustainable use in pavements and foundations.

Expected Outcomes

• Enhanced UCS and CBR values through geopolymer stabilization
• Improved ductility via natural and PET fiber reinforcement
• Reduced environmental footprint compared to cement/lime methods
• Sustainable stabilized marl for pavements and foundations

The Research Timeline slide outlines a project progression starting in 2025 Q1-Q2 with a literature review, material preparation, and initial tests on marl soil. It continues in 2025 Q3-Q4 with core experiments involving geopolymers and fibers plus data analysis, culminating in 2026 Q1-Q2 for final testing, thesis writing, and defense preparation.

Research Timeline

2025 Q1-Q2: Literature Review and Preparation Conduct literature review, prepare materials, and perform initial tests on marl soil. 2025 Q3-Q4: Main Experiments and Analysis Execute core experiments with geopolymers and fibers, followed by data analysis. 2026 Q1-Q2: Final Testing and Thesis Completion Conduct final tests, write thesis, and prepare for defense presentation.

Source: MS Thesis Proposal: Stabilization of Marl Soil Using One-Part Geopolymers and Fibers

The slide lists key references in APA style on topics like marl soil characterization, geopolymer chemistry, clayey soil stabilization with industrial byproducts, and fiber-reinforced geopolymer-stabilized soils. It concludes with a thank-you message and an invitation for thoughts and questions.

References

**Key References (APA Style)

Ahmed, A. J. (2024). Preliminary characterization of marl soil in arid regions. Journal of Geotechnical Engineering, 150(2), 45-56.

Davidovits, J. (2015). Geopolymer chemistry and applications (4th ed.). Geopolymer Institute.

Phummiphan, I., et al. (2018). Clayey soil stabilization using alkali-activated rice husk ash and ground granulated blast furnace slag. Construction and Building Materials, 172, 669-678.

Tang, C. S., et al. (2020). Fiber-reinforced geopolymer-stabilized soils: A review. Geotextiles and Geomembranes, 48(4), 512-525.

Closing Message: Thank you for your attention.

Call to Action: Please share your thoughts and questions.**

Sources and Acknowledgments

Source: Thesis Proposal: Stabilization of Marl Soil Using One-Part Geopolymers and Fibers