Introduction

The long-term performance and structural integrity of any road pavement are critically dependent on the stability and strength of its underlying Road Subgrade. Weak or problematic subgrade soils can lead to premature pavement distress, costly repairs, and reduced service life, making effective Soil Stabilization Techniques an indispensable component of modern road construction and rehabilitation. This training course is meticulously designed to equip civil engineers, geotechnical engineers, pavement designers, contractors, and public works professionals with cutting-edge knowledge and practical skills in characterizing various problematic soils, selecting appropriate stabilization methods (e.g., mechanical, chemical, geosynthetic), designing stabilized layers, implementing field construction techniques, and assessing the performance and environmental implications of stabilized subgrades. Participants will gain a comprehensive understanding of how to transform challenging soil conditions into robust and reliable foundations, ensuring enhanced pavement performance, reduced construction costs, and improved sustainability for transportation infrastructure projects.

Target Audience

• Civil Engineers (Geotechnical, Pavement, Transportation)
• Geotechnical Engineers
• Pavement Designers
• Road Construction Contractors
• Materials Engineers & Technicians
• Public Works & Highway Agency Staff
• Consultants in Geotechnical & Pavement Engineering
• Researchers in Soil Mechanics

Objectives

• Understand the fundamental properties of various problematic soils encountered in road construction.
• Identify the mechanisms of soil instability and their impact on pavement performance.
• Master the principles and applications of different mechanical soil stabilization techniques.
• Explore various chemical stabilization methods using cement, lime, fly ash, and other binders.
• Learn about the use of geosynthetics for reinforcement, separation, and drainage in subgrades.
• Design stabilized soil layers to meet specified engineering properties and performance criteria.
• Implement proper field construction techniques for effective soil stabilization.
• Conduct laboratory and field testing to assess the strength, stiffness, and durability of stabilized soils.
• Understand the environmental considerations and sustainability aspects of soil stabilization.
• Evaluate the cost-effectiveness and long-term benefits of different stabilization solutions.
• Develop skills in troubleshooting common issues encountered during soil stabilization projects.

Course Content

Module 1. Introduction to Road Subgrades and Soil Problems

• Role of subgrade in pavement performance and distress
• Classification of soils and their engineering properties (e.g., plasticity, compaction)
• Common problematic soils: expansive clays, soft clays, collapsible soils, dispersive soils
• Impact of moisture content and drainage on subgrade stability
• Overview of subgrade evaluation methods (CBR, resilient modulus)

Module 2. Fundamentals of Soil Stabilization

• Stabilization Mechanisms: Physical, chemical, and mechanical changes in soil properties
• Objectives of soil stabilization: strength, stiffness, durability, volume stability
• Historical development and evolution of stabilization techniques
• Importance of proper material selection and mix design
• Overview of common stabilization methods

Module 3. Mechanical Stabilization Techniques

• Compaction: Principles of soil compaction and compaction control
• Compaction equipment and field procedures
• Granular material stabilization: aggregate blending and quality control
• Soil-aggregate mixtures for improved bearing capacity
• Geosynthetic-reinforced granular layers for subgrade improvement

Module 4. Cement Stabilization (Soil-Cement)

• Cement Properties: Types of cement and their reactions with soil
• Soil-cement mix design: proportioning, water content, and compaction
• Strength and durability characteristics of soil-cement
• Construction methods for soil-cement layers
• Quality control and testing for cement-stabilized soils

Module 5. Lime Stabilization

• Lime Types: Quicklime, hydrated lime, and their reactions with clay soils
• Mechanisms of lime stabilization: flocculation, pozzolanic reactions
• Lime-soil mix design and curing considerations
• Strength development and long-term performance of lime-stabilized soils
• Applications in expansive soils and high-plasticity clays

Module 6. Fly Ash and Other Pozzolanic Stabilizers

• Fly Ash Properties: Types of fly ash (Class C, Class F) and their pozzolanic activity
• Use of fly ash in combination with lime or cement
• Mix design for fly ash-stabilized soils
• Strength and durability of fly ash-stabilized layers
• Environmental benefits and considerations of using fly ash

Module 7. Slag and Other Industrial Byproducts for Stabilization

• Slag Types: Ground Granulated Blast Furnace Slag (GGBS) and steel slag
• Mechanisms of stabilization with slag-based binders
• Mix design and curing of slag-stabilized soils
• Performance characteristics and applications
• Case studies of industrial byproduct utilization

Module 8. Chemical Stabilization with Non-Traditional Binders

• Polymer Stabilizers: Acrylics, emulsions, and other organic polymers
• Enzyme-based stabilizers and their mechanisms
• Lignosulfonates and other waste-derived stabilizers
• Proprietary chemical additives and their claims
• Evaluation and validation of non-traditional stabilizers

Module 9. Geosynthetics for Subgrade Improvement

• Geosynthetic Types: Geotextiles, geogrids, geocells, geomembranes
• Functions of geosynthetics: separation, reinforcement, filtration, drainage
• Design principles for geosynthetic-reinforced subgrades
• Installation techniques and quality control for geosynthetics
• Applications in soft soils, embankments, and retaining structures

Module 10. Design of Stabilized Soil Layers

• Design Inputs: Characterizing stabilized soil properties for pavement design (CBR, resilient modulus)
• Thickness design of stabilized layers based on traffic and performance
• Drainage design for stabilized subgrades
• Considerations for frost-susceptible soils
• Integration of stabilized layers into overall pavement structure

Module 11. Field Construction Techniques for Soil Stabilization

• Equipment: Mixing equipment (pulverizers, rototillers, pugmills)
• Spreading and compaction equipment
• Curing methods for chemical stabilization
• Quality control during construction: density, moisture, thickness
• Common construction challenges and mitigation strategies

Module 12. Laboratory Testing of Stabilized Soils

• Index Properties: Atterberg limits, sieve analysis of stabilized soils
• Compaction characteristics (Proctor test)
• Unconfined Compressive Strength (UCS) testing
• California Bearing Ratio (CBR) testing
• Durability tests: wet-dry, freeze-thaw cycles

Module 13. Field Performance Assessment and Monitoring

• In-Situ Testing: Dynamic Cone Penetrometer (DCP), Light Weight Deflectometer (LWD)
• Falling Weight Deflectometer (FWD) for backcalculation of moduli
• Long-term performance monitoring of stabilized subgrades
• Identifying and addressing distresses in stabilized layers
• Case studies of field performance

Module 14. Environmental and Sustainability Considerations

• Environmental Impact: Energy consumption and greenhouse gas emissions of stabilization methods
• Leaching potential of stabilized materials
• Resource conservation and waste utilization benefits
• Life cycle assessment (LCA) for soil stabilization projects
• Sustainable practices in material sourcing and application

Module 15. Advanced Topics and Future Trends

• Smart Stabilization: Self-healing and smart materials for subgrades
• Use of nanotechnology in soil stabilization
• Biogeotechnical techniques: microbial induced calcite precipitation (MICP)
• Data analytics and AI for optimizing stabilization designs
• Emerging research and innovative materials for subgrade improvement.

Training Approach

This course will be delivered by our skilled trainers who have vast knowledge and experience as expert professionals in the fields. The course is taught in English and through a mix of theory, practical activities, group discussion and case studies. Course manuals and additional training materials will be provided to the participants upon completion of the training.

Tailor-Made Course

This course can also be tailor-made to meet organization requirement. For further inquiries, please contact us on: Email: info@skillsforafrica.org, training@skillsforafrica.org Tel: +254 702 249 449

Training Venue

The training will be held at our Skills for Africa Training Institute Training Centre. We also offer training for a group at requested location all over the world. The course fee covers the course tuition, training materials, two break refreshments, and buffet lunch.

Visa application, travel expenses, airport transfers, dinners, accommodation, insurance, and other personal expenses are catered by the participant

Certification

Participants will be issued with Skills for Africa Training Institute certificate upon completion of this course.

Airport Pickup and Accommodation

Airport pickup and accommodation is arranged upon request. For booking contact our Training Coordinator through Email: info@skillsforafrica.org, training@skillsforafrica.org Tel: +254 702 249 449

Terms of Payment: Unless otherwise agreed between the two parties’ payment of the course fee should be done 7 working days before commencement of the training.