Memorandum from R. L. Murray and A. C. Menius to Dr. Clifford K. Beck
2 pp.
July 14, 1951

July 14, 1951

TO: Dr. Clifford K. Beck
FROM: R. L. Murray and A. C. Menius
SUBJECT: Reactor Concrete Tests (Preliminary Report)

This report summarizes the recent investigations of reactor concrete
mixes by Professor C. R. Bramer of the Civil Engineering Department. We are
glad to report that the experiments were very successful, thanks to Mr. Bramer's

Two shipments of barytes aggregate were tested.

The first of these consisted of two separate sizes: what will be labeled
"coarse," ranging from 1" maximum diameter stones to about 1/4", with very
little fine material; what will be labeled "fine," ranging from a 1/4" maximum
down below that transmitted by a 16 mesh screen; of the fine material 62% goes
through that screen, the rest is retained.

The second shipment was a uniformly graded mixture ranging from 1" down to

The Colemanite was the sand from the West Coast; Portland cement types I, II
and III (High-early) were on hand.

In previous tests, the mortar had failed to set, which was attributed
by Oak Ridge people to be due to the large amount of water that is normally
added to make the consistency proper for pouring. Thus in the present experi-
, efforts were made to minimize the water content.

As the basic proportions of materials, the Oak Ridge Figures for a cubic yard
were used:

The following table gives the composition of the several batches used
to make test cylinders:

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It would be concluded tentatively that:

It is estimated that the water excess might be cut in half, or even more if a
wetting agent such as Darex is used. Tests on those ideas and a neutron
absorption experiment to determine whether the colemanite is uniformly enough
distributed are planned.

The specific gravity was measured to be 3.4.