1,721,014 research outputs found
An integrated application of geological-geophysical methodologies as a cost-efficient tool in improving the estimation of clay deposit potential: Case study from south-central Sardinia (Italy)
No full textIntegrated ultrasonic and petrographical characterization of carbonate building materials
No full textThis paper presents the application of non-destructive ultrasonic techniques in evaluating the conservation state
and quality of monumental carbonate building materials. Ultrasonic methods are very effective in detecting the
elastic characteristics of the materials and thus their mechanical behaviour. They are non-destructive and effective
both for site and laboratory tests, though it should be pointed out that ultrasonic data interpretation is extremely
complex, since elastic wave velocity heavily depends on moisture, heterogeneity, porosity and other physical
properties of the materials. In our study, considering both the nature of the building materials and the constructive
types of the investigated monuments, the ultrasonic investigation was carried out in low frequency ultrasonic
range (24 kHz – 54 kHz) with the aim of detecting damages and degradation zones and assessing the alterability
of the investigated stones by studying the propagation of the longitudinal ultrasonic pulses. In fact alterations in
the materials generally cause a decrease in longitudinal pulse velocity values. Therefore starting from longitudinal
velocity values the elasto-mechanical behaviour of the stone materials can be deduced. To this aim empirical
and effective relations between longitudinal velocity and mechanical properties of the rocks can be used, by
transferring the fundamental concepts of the studies of reservoir rocks in the framework of hydrocarbon research
to the diagnostic process on stone materials.
The ultrasonic measurements were performed both in laboratory and in situ using the Portable Ultrasonic
Non-Destructive Digital Indicating Tester (PUNDIT) by C.N.S. Electronics LTD. A number of experimental
sessions were carried out choosing different modalities of data acquisition.
On the basis of the results of the laboratory measurements, an in situ ultrasonic survey on significant monuments,
have been carried out.
The ultrasonic measurements were integrated by a petrographical and petrophysical study of the investigated
stone materials to correlate their petrographical-petrophysical features with the elastic ones. From this integrated
study results that the modifications in the elasto-mechanical and petrographical-petrophysical features of the
investigated carbonate materials are the main causes which reduce their quality as building materials.
The use of the ultrasonic method integrated with information on petrography and petrophysics of the rocks has
been successful to assess the rock quality and better understanding their alteration process
Application of integrated acoustic and mineralogical techniques for the characterization of building stones in monumental structures
No full textApplication of integrated EM geophysical and mineralogical-chemical methodologies as useful tool in clay mining exploration
No full textAcoustic techniques for the evaluation of the building materials of monumental structures
No full textDynamic elastic characterization of carbonate rocks used as building materials in the historical city centre of Cagliari (Italy)
No full textThis paper focuses on the dynamic characterization approach to evaluate the conservation
state of carbonate building stones of monumental structures. In particular, we report the use of
elastic waves at an ultrasonic frequency of 54 kHz to define quantitatively some dynamic properties
of carbonate rock types used as building materials. Measurements of compressional and shear wave
velocities have been carried out and the relationship between some physical properties of the investigated
rocks and these geophysical measurements have been evaluated. The ultrasonic data were also
supplemented by a petrographical study of these rocks to correlate their petrophysical features with the
elastic ones. Based on the results of the laboratory measurements, in situ applications on a significant
monumental structure have been also carried out to check zones of weakness and to assess the state
of deterioration of the investigated stones. A comparison of laboratory and in situ results confirms that
dynamic characterization is a useful approach
Integrated interpretation of geological and geophysical data for improving the estimation of the clay deposit potential
No full text
APPLICATION OF NON-DESTRUCTIVE ULTRASONIC TESTING ON THE OLD ABATTOIR OF CAGLIARI (ITALY)
No full textDynamic elastic characterization of carbonatic rocks used as building materials of monumental structures
No full textThis paper focuses on the dynamic characterization approach to evaluate the conservation state of carbonatic building stones of monumental structures. In particular, we report the use of the elastic waves in the ultrasonic range 24-82 kHz to define quantitatively some dynamic properties of carbonatic rock types used as building materials. Measurements of compressional and shear wave velocities have been carried out and the relationship between some physical properties of the investigated rocks and the above mentioned geophysical measurements have been carefully evaluated. The acoustic data were also corroborated by a mineralogical and petrological study of these rocks to correlate their petrophysical features with the elastic ones. On the basis of the results of the laboratory measurements, in situ applications on significant monuments in order to check zones of weakness, to assess the alterability of the investigated stones and evaluate the restoration effectiveness have been also carried out. The comparison of laboratory and in situ results confirms the usefulness of the dynamic characterization approach
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