Masters Theses

Abstract

"As a possible solution for the rapidly proliferating problem of waste glass disposal in the United States, glass is being considered for use as aggregate in bituminous concrete mixtures. Crushed waste glass particles, and crushed bottle glass particles in particular, are more angular, much smoother, and contain a higher percentage of flat and/or elongated particles than conventional rock aggregate particles. Because of the differences in shape and surface texture, glass aggregate may require different gradations than those found suitable for conventional rock aggregate. Objectives of this research were to determine gradations which result in maximum density for aggregates consisting entirely, or in part, of glass; to evaluate the effect of angularity and sphericity of glass particles upon gradations giving maximum density; to find whether maximum density gradations of glass aggregate can be used to produce asphaltic mixtures meeting Marshall design criteria and, if necessary, determine the modifications in gradations necessary to produce asphaltic mixtures meeting Marshall design criteria; and to determine effects of angularity and sphericity of glass particles upon properties of asphaltic mixtures. A series of dry density tests on crushed bottle glass at various gradations were conducted to determine a maximum density gradation. A series of dry density tests were also conducted for glass spheres to study the effects of angularity and sphericity upon the maximum density gradation. In order to isolate the effects of angularity and sphericity of the coarse sized glass particles, different types of coarse glass aggregate were used in combination with fine sized conventional aggregate and a series of dry density tests were conducted for each combination. Dry density tests were also conducted for several gap-gradations to study the effects of eliminating certain sizes of crushed bottle glass on the density of the dry aggregate. Using crushed bottle glass as aggregate, Marshall tests were conducted at different asphalt contents to determine whether Marshall design criteria could be met for a maximum density gradation, or a modification of it. Additional Marshall specimens were made substituting different types of glass aggregate for crushed bottle glass to determine effects of angularity and sphericity of glass particles upon properties of asphalt mixtures. For a dense-graded dry aggregate, the angularity and sphericity of the glass particles affect the gradation that will give maximum density. The more angular the glass particles, the larger the percentage of fines necessary for the maximum density gradation; while the more spherical the glass particles, the wider is the range of gradations giving maximum density, or close to it. The range of gradations is considerably larger for a combination of glass and conventional aggregate than for an all-glass aggregate. The properties of angularity and sphericity of glass particles also affect the void content of the maximum density gradation, a more angular and non-spherical glass aggregate giving a higher void content. Gap-grading does not seem to have a significant effect on the maximum density gradation, for a dense-graded mixture, although somewhat higher density gradations may be obtained by eliminating certain size fractions. The maximum density gradation for crushed bottle glass does not produce an asphaltic mixture meeting Marshall design crieteria, but the gradation can be modified to produce an asphaltic mixture that will meet these criteria. Dry density tests for dense-graded aggregate does not give a good indication of densities obtained in asphaltic mixtures using the same aggregate. Sphericity of coarse sized glass particles has little effect upon the Marshall properties, but a decrease in angularity decreases the stability and void content while increasing the flow. The strength of a glass aggregate asphaltic mixture appears to derive almost entirely from the interlocking resistance developed between particles"--Abstract, pages ii-iv.

Advisor(s)

Malisch, Ward R.

Committee Member(s)

Wixson, Bobby G.
Day, D. E.

Department(s)

Civil, Architectural and Environmental Engineering

Degree Name

M.S. in Civil Engineering

Sponsor(s)

United States. Bureau of Solid Waste Management

Publisher

University of Missouri--Rolla

Publication Date

1971

Pagination

x, 63 pages

Rights

© 1971 John Dean Doyle, All rights reserved.

Document Type

Thesis - Open Access

File Type

text

Language

English

Subject Headings

Waste products as road materials -- TestingGlass waste -- RecyclingPavements, Asphalt -- TestingPavements, Asphalt concrete -- Maintenance and repair

Thesis Number

T 2642

Print OCLC #

6039120

Electronic OCLC #

876294293

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