Environmental Engineering Reference
In-Depth Information
Chapter 10
Experimental Techniques for
Characterizing Alterations
10.1. Laboratory and
in situ
testing
Characterization of stones and their alteration is a compulsory step before
restoration work, whatever the monument, statue or other artwork concerned.
It starts with
in situ
investigations that are essentially based on visual inspection.
This study provides important information, first on the nature of the stone and then
on the rate and type of degradation (black crust deposits, wall leaching, plate
formation or granular disintegration, alveolization, loss of material, lichen
colonization, and plants can be seen with the naked eye). Here we may use accurate
observation tools that make it possible to observe the stone surface in detail, such as
through binocular lenses, portable stereoscopic microscope (possibly connected to a
video device), and digital camera.
This on-field examination is described in detail by Bromblet [BRO 94] within
the frame of restoration of the portal of Saint Gilles church at Argenton-Château
(Deux-Sèvres). It is conducted with participation of the architect, conservator,
curator and every other person who may be able to provide information about the
condition of the monument, its previous restorations and history. At the end of this
examination, it is then possible to produce a cartographic work for the monument
(see Figure 10.1) showing typical features, such as the type of stone, alteration
morphology, lost material and biological colonization [BRO 94, FIT 92, VER 92a].
Chapter
written
by
Claude
B
RUNJAIL
,
Guy
B
ASTIAN
,
Grégoire
C
HÉNÉ
and
Véronique V
ERGÈS
-B
ELMIN
.
Updated by
Philippe
B
ROMBLET
.
