Although many engineers had pro-
posed the idea of prestressing even as
far back as 1886, no one had based the
idea on a clear understanding of the
properties of the concrete. Thus, all
previous ideas had failed to produce
what is now called prestressed con-
crete.
19
Freyssinet saw, in general, the wide
potential for his idea, which used what
he called “treated” concrete, but in
particular, he had great difficulty in
establishing any commercial value for
it. Partly of course, in 1933 France
was in the midst of the worldwide
economic depression, but partly too it
was a genuinely radical idea. Seen as a
means for improving arch design, his
system of crown jacking was accepted
both in Europe and the United States
and used as early as 1930 in Oregon;
20
but seen as a new material, prestress-
ing found little application in its early
years.
Freyssinet himself developed a fac-
tory at Montargis (south of Paris),
France, where he manufactured pre-
stressed concrete poles (see Fig. 3) for
electric lines, but he could not make
the business succeed. The factory
closed not long after his 1933 article
appeared and as Freyssinet later put it
“our factory was without customers
and was only good for scrap; my wife
and I were ruined.”
21
But not for long, because in 1935 he
had the opportunity to prove the mer-its of prestressing by saving the Mar-
time Terminal at Le Havre, parts of
which had been settling into the har-
bor at the alarming rate of about 1 in.
(25.4 mm) per month.
Freyssinet proposed to consolidate
the foundations by prestressing and
his success so convinced the French
authorities that they then supported
numerous large-scale projects between
1935 and 1939 where prestressing
proved its practical merit. Freyssinet’s
retrospective attitude on the Marine
Terminal restorations is intriguing: