Masters Theses

Abstract

"Ultrasonic probes have been constructed for use in the dynamic and nondestructive testing of asphaltic concrete specimens. The probe systems exhibited characteristics superior to the solitary ii use of their main components, the piezoelectric crystals. The probes have the advantages of the reduction of ringing time, the concentration of ultrasound in one direction, the elimination of "noise" due to unshielded connections and the increased durability of the probe system.

The probes constructed were used in a limited testing program. Compression and transverse wave velocities in the specimens tested were measured simultaneously. Sample conditions suitable for maximum wave velocity corresponded to conditions producing maximum strength and minimum voids in the mineral aggregate (percent V.M.A.). A relationship of increasing wave velocity with increasing strength was noted. Wave velocity was observed to increase with decreasing percent V.M.A.

Various "elastic" constants were calculated from the wave velocities measured. The variation in these dynamic values (Young's modulus, E, shear modulus, G, and Poisson's ratio,μ) with changes in asphalt content were observed.

Relative attenuation measurements were conducted using water as a standard material. An evaluation of relative attenuation with changes in asphalt content was conducted and a trend was observed but was not considered definite due to the limited number of samples tested"-- Abstract, p. ii

Advisor(s)

Stephenson, Richard Wesley

Committee Member(s)

Malisch, Ward R.
Rockaway, John D.

Department(s)

Civil, Architectural and Environmental Engineering

Degree Name

M.S. in Civil Engineering

Publisher

University of Missouri--Rolla

Publication Date

1975

Pagination

ix, 103 pages

Note about bibliography

Includes bibliographical references (pages 98-102)

Rights

© 1975 John Edward Hill, All rights reserved.

Document Type

Thesis - Open Access

File Type

text

Language

English

Thesis Number

T 4012

Print OCLC #

5981785

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