Abstract :

Expansive Clayey Soils, Characterized By High Plasticity, Low Bearing Capacity, And Pronounced Volumetric Swell-shrink Behavior, Present A Persistent Geotechnical Challenge For Foundations, Embankments, And Pavement Subgrades In Arid And Semi-arid Regions. Lime Stabilization Is A Well-established Chemical Treatment For Reducing Plasticity And Swelling, But Lime-treated Soils Remain Relatively Brittle And Can Develop Shrinkage Cracks That Compromise Long-term Durability. This Paper Presents LPFS (Lime– Polypropylene Fiber Stabilization), A Combined Experimental Investigation Into The Geotechnical Behavior Of An Expansive Clayey Soil Treated With Hydrated Lime And Discrete Polypropylene (PP) Fiber Reinforcement. Soil Specimens Were Prepared At Lime Contents Of 0, 2, 4, 6, And 8% By Dry Weight To Identify The Optimum Lime Dosage, After Which Polypropylene Fiber Was Incorporated At 0, 0.3, 0.6, 0.9, And 1.2% By Dry Weight At The Optimum Lime Content To Identify The Optimum Fiber Dosage. Unconfined Compressive Strength (UCS), Soaked California Bearing Ratio (CBR), Free Swell Index, And Wet-dry Durability Tests Were Carried Out On Treated And Untreated Specimens Cured For 7, 28, And 90 Days. The Results Show That 6% Lime Content Produced The Highest Practical Gain In 28-day UCS, Beyond Which Additional Lime Yielded Only Marginal Improvement. At This Optimum Lime Content, The Addition Of 0.9% Polypropylene Fiber Increased The 28-day UCS By Approximately 29% Relative To The Lime-only Mix And By Close To 500% Relative To The Untreated Soil, While Increasing The Failure Strain At Peak Stress By More Than Three And A Half Times, Indicating A Marked Improvement In Post-peak Ductility. The Combined Lime-fiber Treatment Increased The Soaked CBR From 2.1% For The Untreated Soil To 13.8%, And Reduced The Free Swell Index From 92% To 24%. Under Twelve Cycles Of Wet-dry Durability Testing, The Lime-fiber Specimens Retained Substantially More Mass Than The Lime-only Specimens, Confirming Improved Resistance To Moisture-induced Deterioration. The Results Demonstrate That Combined Lime And Polypropylene Fiber Treatment Offers A Sustainable, Low-cement-content Stabilization Strategy That Simultaneously Improves Strength, Bearing Capacity, Volumetric Stability, Ductility, And Durability Of Expansive Subgrade Soils.

Published:

15-11-2023

Issue:

Vol. 23 No. 11 (2023)

Page Nos:

308 - 317

Section:

Articles

License:

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

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