Doctoral Dissertations

Keywords and Phrases

Geofoam

Abstract

"Soils modified with expanded polystyrene (EPS) particulates could be used as lightweight fill in a variety of installations including slopes for improved stability, embankments over compressible soils, and to reduce earth pressures next to structures. The addition of low density EPS particulates into soil has a large effect on the mass and volumetric characteristics of these mixtures and their influence on mechanical properties is scarce in the literature. A laboratory characterization program using clay mixed with EPS particulates was conducted for different dosages of EPS. Soils were modified with up to 1.5% EPS by mass, which corresponds to approximately 45% EPS by volume. This research focused on the laboratory evaluation of the individual constituents followed by the engineering characterization of composite mixtures at increasing percentages of EPS. The preparation of unit element specimens for the mixtures were developed using slurry consolidation and mechanical compaction. For each half percent increase in EPS content there was a reduction of 8% to 12% in dry unit weight and an increase in equivalent void ratio of 15 to 22%. Therefore, the reduction in dry unit weight is significant for use as soil fill. The evaluation of the mechanical properties of the soil/EPS mixtures included: swell, compression, and shear strength. The low strain dynamic properties (shear modulus and damping) were examined using the following devices: resonant column apparatus, bender elements, and ultrasonic pulse velocity transducers. Results indicate that the strength of the modified soils was not compromised with the addition of up to 1% EPS by mass. The percent free swell and swell pressure reduce with increasing EPS content, but the compressional strain prior to inundation increases with increasing EPS content. The dynamic properties indicate decreased shear stiffness with increasing EPS content, but the material damping is relatively unaffected by the EPS content. Even though the shear modulus decreased in magnitude, the specimens exhibit elastic behavior for a wider range of strain. Overall, the laboratory evaluation of these soil/EPS mixtures resulted in properties that are within the range of engineering use and could be considered as alternative construction materials in civil engineering applications"--Abstract, page iii.

Advisor(s)

Luna, Ronaldo

Committee Member(s)

Stephenson, Richard Wesley
Rogers, J. David
Anderson, Neil (Neil Lennart), 1954-
Ge, Louis, Yu-Ning

Department(s)

Civil, Architectural and Environmental Engineering

Degree Name

Ph. D. in Civil Engineering

Sponsor(s)

United States. Department of Education

Publisher

Missouri University of Science and Technology

Publication Date

Fall 2012

Pagination

xix, 199 pages

Note about bibliography

Includes bibliographical references (pages 184-198).

Rights

© 2012 Nicholas Thomas Rocco, All rights reserved.

Document Type

Dissertation - Open Access

File Type

text

Language

English

Library of Congress Subject Headings

Shear strength of soils
Swelling soils
Sediment compaction
Dynamic testing
Polystyrene -- Expansion and contraction

Thesis Number

T 10149

Print OCLC #

853508770

Electronic OCLC #

842836873

Comments

Appendix contains "Stereoscopy images; SEM images, procedures for preparing piezoelectric elements; Compress-Swell test results; resonant column test results; UU triaxial / CU triaxial / resonant column / bender element pulse velocity / ultrasonic pulse velocity raw (*.csv) data files".

DAQ_Files.zip (28151 kB)
DAQ Files

RC_99Kaolin.xlsx (57 kB)
Specimen A - 1

RC_100Kaolin.xlsx (59 kB)
Slurry Specimen

RC_995Kaolin.xlsx (56 kB)
Specimen A - 2

Appendix A.pdf (184 kB)
Stereoscopy

Appendix B.pdf (8853 kB)
Scanning Electron Microscopy Images

Appendix C.pdf (263 kB)
Procedures for Cutting Piezoelectric Elements and Exposing Center Electrode

Deformation_vs_Stress_99Kaolin.pdf (27 kB)
Deformation_vs_Stress_99Kaolin

Deformation_vs_Stress_100Kaolin.pdf (31 kB)
Deformation_vs_Stress_100Kaolin

Deformation_vs_Stress_985Kaolin.pdf (31 kB)
Deformation_vs_Stress_985Kaolin

Deformation_vs_Stress_995Kaolin.pdf (30 kB)
Deformation_vs_Stress_995Kaolin

Time_Deformation_Curve_99Kaolin.pdf (35 kB)
Time_Deformation_Curve_99Kaolin

Time_Deformation_Curve_100Kaolin.pdf (35 kB)
Time_Deformation_Curve_100Kaolin

Time_Deformation_Curve_985Kaolin.pdf (35 kB)
Time_Deformation_Curve_985Kaolin

Time_Deformation_Curve_995Kaolin.pdf (35 kB)
Time_Deformation_Curve_995Kaolin

Share

 
COinS