Masters Theses


"The first objective of this investigation was to determine which deposits of clays, shales, and loesses in Missouri are suitable for use in the production of lightweight aggregate by virtue of their expanding characteristics upon heating. The second objective was to determine, if possible, commercially feasible additions that will produce the bloating property in shales that do not naturally bloat.

There are two conditions which must be met in firing in order to bloat a clay or shale. First, a gas must be formed and evolved during firing. Second, enough glass of the proper viscosity must be formed to trap the gas and permit expansion.

There has been a good deal of research conducted in an effort to determine the bloating agents. The only conclusion one can draw in general from this work is that the bloating agents vary and it is difficult to tie down specifically the agents and reactions involved, and in this regard each clay and shale is a separate problem. It is a matter of record, however, that the majority of shales show some bloating, this was also found true of Missouri shales. In this work, no direct attempt was made to determine gas producing agents since in the majority of cases these agents occurred naturally in the shales. Therefore, the second part of this work was concerned with finding a suitable additive which would promote the formation of glass of the proper viscosity at the right temperatures.

This problem is of considerable economic importance since there is an acute demand for lightweight concrete aggregate. Lightweight concrete aggregate is very popular for use in the production of concrete blocks because of its lightweight, insulating and acoustic properties. In large concrete structures the use of lightweight aggregate can effect a very worth while saving in structural steel and thus justify its slightly higher cost.

Previous to this work very little had been known as to the bloating characteristics of the clays and shales in Missouri.

In the process of this investigation, firing behaviors have been run on all the samples collected and these data might in the future be valuable to the structural clay products industry"--Introduction, pages 1-2.


Herold, P. G.


Materials Science and Engineering

Degree Name

M.S. in Ceramic Engineering


Missouri. Geological Survey
Missouri Resources and Development Commission
Missouri School of Mines and Metallurgy. Ceramic Engineering Department


Missouri School of Mines and Metallurgy

Publication Date



vi, 112 pages

Note about bibliography

Includes bibliographical references (page 110).


© 1953 Peter Kurtz, Jr., All rights reserved.

Document Type

Thesis - Open Access

File Type




Subject Headings

Shale -- Missouri -- Analysis
Clay -- Missouri -- Analysis
Loess -- Missouri -- Analysis
Lightweight concrete
Aggregates (Building materials)

Thesis Number

T 1056

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Electronic OCLC #