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MONITORING
› NON-DESTRUCTIVE TESTS
The Non Destructive Tests (NDT) consists
in a series of assessments, tests
and surveys carried out with methods
that do not alter the material and do
not require the destruction or removal
of samples from the structure tested,
aimed at finding and identifying structural
defects of the same structure. The
acronym NDT derived from the English
expression Non Destructive Testing, is
often used or acronym P.n.D., derived
from Non Destructive tests (in Italian).
In the industrial sector, each product
of critical importance (beams for construction,
support screws, aeronautical
components, car components, pressure
bodies) must be checked to assess
its integrity and conformity with
applicable laws. The primary objective
of non destructive tests is therefore to
foresee the cracking of materials and
objects, thus covering an essential role
to prevent economic damages due to
possible accidents and also to guarantee
a high level of safety for operators.
Reinforced concrete structures
(masonry), particularly important for
their long-life and unlimited endurableness
to continuous and uncontrollable
changes, excluding disastrous
events (earthquakes, thermal shocks,
landslides, etc), ) in the majority of
the cases showed phenomena of progressive
deterioration during their life.
These defects are linked to the executive
phase of the works, aggressiveness
of building materials (alkalis – silica
reactions), micro-holes produced
by water-thermal variations, sagging
of foundations or grounds, static-dynamic
operating stresses. The non invasive
character of this method applicable
to existing works allows to verify
the physical and mechanical characteristics
of the materials that constitute
the structure.
› MEASUREMENT OF HEAT TRANSMISSION ON SITE
In building technology, the testing of
the insulation capacity of building materials
is an important topic of study. In
addition to laboratory measurements
of the thermal properties of materials,
their behaviours is also studied through
tests on field, in order to obtain information
on the behaviours in different
climates. The total heat flow through a
material consists of a conductive, convective
and radioactive part. In order to
measure the heat transmission, a heat
flow meter and some thermometers
are used, assembled on both sides (interior
and exterior) of a wall. After recording
the flow and temperatures for
a few hours, measured with high precision,
the data is elaborated to obtain
the average heat transmission of
the wall.