Year: 1868

From the Gazette Of the Association


Of German Railacay Administrator, the


Iron Age takes the following report con-


cerning the preparation Of a very dur


able mortar, and of the experiments


made with it,


''It is well known that the mortar used


by the Romans made far more dur


able masouary than modern mortar. The


modern mortar hardens very slowly,


tears after hardening, does not become


very firm, crumbles easily after a con-


siderable period has elasped, and does


not uuite well with the building mater


ial so that after thoroughly hardening


there is but little difficulty in removing


single stones from the top layers of


masonary. The modern mortar effects


less a real union between the stones and


bricks of masonary, but rather only


lays them closer together, while the


weight of the materials themselves far


more insures the firm union of the lay


ers of stone and mortar. For a lasting


finish common mortar can not be used,


because of the above named qualities.


Neither can it be used for masonary


under water, as it softens in the water,
and is washed away. In investigating the
mortar of old Roman masonaTy, 1t was
discovered that the mortar had for the
greater part been converted into silicates,
which had entered into very close union
with the quartz particles. 1t is well
known that with modern mortar the
formation of silicates docs not take place
until after a long time and then only in
very slight measure. But it is just
these silicates which give mortar firm
ness, and at the same time make 1t
capable of resisting the action Of water.
1t is to the formation Of such silieates
that cement owes its hardness and i'm
perviousness to water. Lately, Prof.
Artus discovered a method of preparing
mortar by which the silieious earth IS,
according to the chemical term, set free
and the formation of silieates greatly
promoted. The mortar prepared after
this method hardens much more rapidly
than common mortar, attains eq1al hard
ness with cement, and forms no tears
while drying. 1t may also be accepted
that it can be used under water in the
place Of cement. Still, until now, only
experiments in which the Artus mortar
has proved its excellence as air mortar,
have been reported to Us, while of its
utility in the place of cement under
water no confirmatory experiments have
as yet been made known TO US.


''The method employed by DR.. Artus
is extremely simple. Take well Stacked
lime, and mix carefully with it finely
sifted sand when this has has been done
let there be added one-quarter as much
fine unslacked lime as there has been
sand used, and mix throughly. While
it being mixed the mass heats and the
mortar may then be Immediately used |
Of course the unslackedl lime must not
be added to the mass until it is wanted
for used. During the heating of the
mass silicates form through which it
quickly stifens and becomes very hard
in short time. Thus mortar forms no
tears. Itresists all action of the water
and can therefore be used whenever /
durability is an object. This mortar
clings so firmly that after a short time
even considerable force has to be used |
to separate it from the building material. /
made with it have yielded /.
brilliant results, so that the writer may
believe to have solved the former So
called mortar secret. This is what Dr. /
Artus writes in his quartely periodical. /
An experiment known to us yielded the /
result One part Of well slack /
I'd lime was carefully mixed with three /
parts of fine sand, and Just before using, !
three-fourths part of fine unslaeked I
lime was added, and the whole then
mixed. The mortar thus pre-
pared was used in building foundation
wall, and after four days became so hard /
hat pointed iron could not be driven
into it it clung with equal tenacious
ness to the stones of the wall. After
Two months the mortar was just as hard /
as stone. We have then, here, very
discovery under consideration,
which must also be of great account from
an enconomical point of view, when the
nigh price of cement is remembered.
It should be more definitely proved
how long the mortar can be used after
and how large quantities may
20 used at once. In following up the
race discovered, by means of rational
and by making use of the
discoveries made in this line,
t would perhaps be possible to substi-
ute cheap, simple mertar for the ex-
Jensive cement. In the interest Of
cienee, and no less Of practical appliea-
ion. more definite explanation of the
,hemical process which takes place dur
ng the preparation of this new mortar,
would be very desirable"