Civil Engineering Reference
In-Depth Information
but as used for special occasions and connections (NB bath buildings). Some such
date (and no later!) for the inception of burnt brick construction is requisite, since
all accounts of the development of
opus testaceum
concrete during the 1st century
AD refer to the brick facing as originally from reused rooi ng tiles and burnt brick
masonry but with very little evidence for the supply of pre-existing burnt brick
(Vitruvius 2.8.19; cf Vol. 2, pp. 116, 199).
With the dominance of
opus testaceum
concrete the rationale of the Roman brick
industry became ever more dif used. h ere is evidence to show that on occasion
square burnt bricks were shaped into triangular facing units either by sawing apart
diagonally, or by dressing away (Vol. 2.2 ill 239). h ere is also evidence that the
Roman brickyards continued to produce square burnt bricks. One thing is certain.
Roman brickyards did not produce square bricks of varying sizes, so that subse-
quently these bricks were to be laboriously sawn apart etc. for use as triangular
facing units to Roman Concrete. Where Roman Concrete was faced with new brick
units, common sense says that these units were supplied pre-fabricated, ready for
use by the brickyards. NB h e exposed side of the triangular brick facing units
to
opus testaceum
was the hypotenuse. If the units were old brick divided up, the
tooling should be exposed to view on the elevation of the wall. If they were new
specially moulded bricks then equally this should be visible.
However the supply of brick facing units was arranged the l oruit of
opus tes-
taceum
construction meant that the aspect of Roman building was transformed
into one of brick masonry. And it is accepted that during the second century AD
(Trajanic, Hadrianic and Antonine times) this brick masonry was of the highest
possible excellence—a sort of equivalent to 5th Century BC Classical Greek ashlar
stone masonry. h ese circumstances are one of the justii cations for stating that
Roman brick construction transformed brick building in the Ancient World.
Following on this statement it may sound strange to assert that precisely these
circumstances are the occasion for a lacuna in the published accounts of Roman
brick work. h eoretically the i ne aspect of the brick masonry of this age could
represent quite dif erent categories of construction—e.g. solid load bearing brick or
opus testaceum
Roman Concrete. h e dif erence in construction is, of course, fun-
damental: load bearing brickwork formed of entire square bricks bonded together;
opus testaceum
formed of triangular brick segments applied without any bond.
Obviously in discussing Roman brick construction it is imperative to know which
construction is employed in any given instance. Such a state of af airs, however, is
not the case in publications. Adam (Chap. 5.7, La Brique, pp. 157-63) systematically
avoids any distinction in building construction and applies his remarks concerning
Roman brickwork generically to all building manifesting a brick masonry aspect.
Ward Perkins, also, repeatedly discusses buildings in terms of their brick masonry
aspect, but neglects to specify the construction (e.g. pp. 284-89). Furthermore
As load
bearing
structure
& as
facing to
Roman
Concrete
381
374
