PORTABLE DEVICE FOR DRILLING RESISTANCE TEST METHOD Alessio - - PowerPoint PPT Presentation
PORTABLE DEVICE FOR DRILLING RESISTANCE TEST METHOD Alessio Benincasa, SINT Technology PRESENTATION CONTENTS Laboratory and on site tests The Drilling Resistance test method The DRMS: portable device for drilling resistance tests
✓ Laboratory and on site tests ✓ The Drilling Resistance test method ✓ The DRMS: portable device for drilling resistance tests ✓ Main features and advantages ✓ Statistical analysis and test procedure ✓ On site tests: example of activity ✓ The DRILL 7 software: acquisition ✓ The DRILL 7 software: elaboration and export ✓ Typical test results
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LABORATORY TESTS: ✓ Tests on specimens of the same monumental stone:
✓ Minimum size for a representative sample should be not less than 5x5x5 cm. ✓ Laboratory test results should be considered only as a preliminary indication Evaluation of the performance of different materials (natural stones, mortars) and of conservation products applied during restoration work such as consolidating or protective treatments.
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Evaluation of the performance of different materials (natural stones, mortars) and of conservation products applied during restoration work such as consolidating or protective treatments. ON SITE TESTS GIVE THE FOLLOWING BENEFITS: ✓ The possibility of evaluating the specific state of conservation of the stone material to be treated with its local environmental exposure. ✓ Determination of actual stone features and properties and the effect of the applied treatment. The results of in situ tests are an essential input for effective maintenance programming.
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The Drilling Resistance Test Method can be used for the characterization of materials, in order to obtain information about the mechanical properties and the performance of consolidating treatments, both in the lab and on site. The test consists in drilling a small hole at a set constant rotational speed and penetration rate and in measuring the penetration force versus depth.
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material
correlated with the Uniaxial Compression Strength (UCS)
at constant
conditions: Rotation speed (20-1000 RPM) and Penetration rate (5-80 mm/min)
effect
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The Abbey of Badia a Passignano, (11th - 12th Century) The Last Supper Fresco by Domenico Ghirlandaio (1476) Mortars of the Cloister’s wall
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Material Consolidating Product Application mode Time
Decayed Marble Lime water + Saturated solution of ammonium oxalate Arbocel BC 200 pack 2 of Arbocel BC 1000 + 1 of Arbocel BC 200 pack 10 days 16 hours 2nd applicat. After 1 week
Heavy decayed fragment
a marble column After treatment Abbey of Badia a Passignano Before treatment
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Some materials (e.g. mortars and concrete) do present high fluctuations in the drilling resistance around the mean value, due to their intrinsic non homogeneity. These materials need to be characterized not only with average parameters but also through statistical indices that take into account the non uniformity of the material.
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filter at 3Hz)
effect
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The Drill 7 software is an evolution of the previous DRMS 5 and it has been completely renewed, starting from the user interface.
Portable Device for Drilling Resistance Test Method
The setup section is now integrated with new fields in order to define the test and the material being tested in a complete way. It’s also possible to
the measurements in groups and subgroups.
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It’s also possible to create a complete database of the materials tested with the DRMS. Each material can be organized in classes (such as Mortar, Marble and so on) and labeled with its own description. Also the drill bits used during the tests are stored in the database, in order to have a complete list of the holes performed by each drill bit.
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The acquisition of the load cell is now improved and has been increased up to 300 Hz. This allows to have more measurement points in order to increase the precision of the test. It’s also possible to apply a digital signal filter in order to reduce the noise related to the vibration of the drill bit.
Portable Device for Drilling Resistance Test Method
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The drilling test is managed automatically by the software that acquires the data from the DRMS machine in real time . The test starts when the desired rotation speed is reached and the surface of the material under test is found.
Portable Device for Drilling Resistance Test Method
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All the measurements data are stored in a database which allows the classification by groups and sub-groups. A dedicated window with several filters simplifies the research of a particular test in the database.
Portable Device for Drilling Resistance Test Method
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All data stored in the database can be viewed in different ways. It’s also possible to view a single hole and modify its properties, such as filtering and test parameters. The software also allows to load multiple tests in a single graph in order to perform an easy comparison between different holes, and to plot an averaged curve.
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As for some materials (like mortars) the drilling resistance shows high fluctuations around the mean value, it becomes more appropriate to use indices that take into account the non-uniformity of the material (e.g mode, standard deviation, etc). The statistical post-processing is useful to perform this type of analysis. It’s possible to view the data of a set of holes in an histogram graph with the related statistical box-plot
can be overlayed to estimate the data deviation. A set of statistical data is calculated automatically by the software. Last but not least, it’s possible to represent the data in other graphs, such as grouped force vs depth.
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All types of analysis can be exported in different formats such as html, png or tabbed txt
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All files acquired with the old version of the DRMS software can be imported and elaborated with the new application. The data will be stored in a database in order to simplify the organization of the tests.
Portable Device for Drilling Resistance Test Method
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600 RPM – 5 mm/min
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600 RPM – 10 mm/min
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300 RPM – 40 mm/min
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600 RPM – 10 mm/min Portable Device for Drilling Resistance Test Method