Performance Assessment of Precast RC Flooring Units Exposed 40 Years in Aggressive Industrial Environment

2016 ◽  
Vol 711 ◽  
pp. 737-744
Author(s):  
Radu Pascu ◽  
Dan Paul Georgescu ◽  
Adelina Apostu
Keyword(s):  
Steel Industry ◽  
Experimental Methods ◽  
Mechanical Tests ◽  
Knowledge Level ◽  
Industrial Environment ◽  
Aggressive Environment ◽  
Observed Damage ◽  
Non Destructive ◽  
Non Destructive Techniques

Performance of RC members is tightly closed to their environment. A long exposition time in aggressive environment corresponds frequently with the use of RC elements designed and produced in an epoch when technical norms, reflecting the knowledge level of the time, were insufficient to insure the durability of the elements.This paper presents the assessment of precast flooring units after 40 years of exposition in an aggressive industrial environment, specific to the steel industry. The assessment was performed using chemical and mechanical tests performed in situ and in the laboratory, using destructive as well as non-destructive techniques, applied at material and member level. Experimental methods were corroborated with calculation results.The paper presents also the steps which were taken in order to asses the performance of the concrete structural elements.The results of this study allow concluding about the causes which led to the observed damage and the identification of the remedial measures needed to restore the security of the investigated elements.

Non-Destructive Tests and Bending Tests on Chestnut Structural Timber

2013 ◽  
Vol 778 ◽  
pp. 167-174 ◽  
Author(s):  
Beatrice Faggiano ◽  
Maria Rosaria Grippa ◽  
Bruno Calderoni
Keyword(s):  
Research Study ◽  
Timber Structures ◽  
Structural Elements ◽  
Bending Tests ◽  
Experimental Activity ◽  
Collapse Mechanisms ◽  
Regression Approach ◽  
Non Destructive ◽  
Non Destructive Techniques

In the context of a more wide research study for in situ mechanical identification of ancient timber structures by non-destructive techniques, the paper illustrates the experimental activity developed on structural elements made of old chestnut timber, 4x4x76 cm size: 24 squared specimens were extracted by six elements in actual dimensions, already used in a previous tests campaign. Non-destructive (ND: hygrometric, sclerometric and resistographic) and destructive (D: bending) tests were performed, the latter according to UNI EN 408 (2004) standard, in order to assess the mechanical properties and the collapse mechanisms of chestnut timber. Data gathered are presented in detail and, NDT-DT correlations, obtained through a linear regression approach, are provided to predict wood density, strength and modulus of elasticity of the tested members.

scholarly journals Research on the Organic Binders in Archaeological Wall Paintings

2021 ◽  
Vol 11 (19) ◽  
pp. 9179
Author(s):  
Antonella Casoli
Keyword(s):  
Chemical Composition ◽  
Organic Material ◽  
Wall Painting ◽  
Wall Paintings ◽  
Chromatographic Techniques ◽  
Invasive Techniques ◽  
Non Destructive ◽  
Potential Tool ◽  
Non Destructive Techniques

Wall painting realized using organic binders is the oldest form of parietal painting and precedes the birth of the affresco by about 20,000 years. This paper reports the results obtained from the main studies in the field of archaeological wall paintings. The attention was paid to the study of organic binders used for the application of the color, as well as on the instrumental techniques chosen to obtain such information. Different techniques can be used for the study of organic material in archeological paintings: non-destructive techniques, which can be applied directly in situ without sampling, and laboratory micro-invasive techniques for a more in-depth characterization. Among these, the chromatographic techniques represent a potential tool to acquire as much information as possible about chemical composition of binders.

Comparison between different non-destructive techniques methods to detect and characterize impact damage on composite laminates

2019 ◽  
Vol 54 (5) ◽  
pp. 617-631 ◽  
Author(s):  
I Papa ◽  
MR Ricciardi ◽  
V Antonucci ◽  
A Langella ◽  
J Tirillò ◽  
...  
Keyword(s):  
Composite Laminates ◽  
Impact Damage ◽  
Speckle Pattern ◽  
Contact Point ◽  
Mechanical Tests ◽  
Low Velocity Impact ◽  
Electronic Speckle Pattern Interferometry ◽  
Internal Damage ◽  
Non Destructive ◽  
Non Destructive Techniques

This paper aims to investigate the ability of ultrasonic and electronic speckle pattern interferometry to analyse the low-velocity impact internal damage mechanisms on basalt composite laminates and to provide information on the shape and the extent of the delamination in non-destructive way. Basalt/epoxy composites with different thicknesses have been realised and characterised by mechanical tests to investigate both fibre-dominated (tensile and flexural behaviour) and matrix-dominated properties (interlaminar shear strength). Specimens were impacted at penetration and at increasing energy values, to explore the damage onset and propagation. The results showed that the damage was concentrated under the impactor–material contact point and that the composite with intermediate thickness had the best balance between the different kinds of impact damages: delamination and indentation. Further, a good agreement was found between the overall data obtained by the two non-destructive techniques, confirming the capability of both techniques to examine the composite impact damage.

scholarly journals Decay detection in an ancient column with combined close-range photogrammetry (CRP) and ultrasonic tomography.

2021 ◽  
Author(s):  
Giuseppe Casula ◽  
Silvana Fais ◽  
Francesco Cuccuru ◽  
Maria Giovanna Bianchi ◽  
Paola Ligas ◽  
...  
Keyword(s):  
High Resolution ◽  
Diagnostic Process ◽  
Ultrasonic Tomography ◽  
Invasive Approach ◽  
Non Invasive ◽  
Close Range Photogrammetry ◽  
Close Range ◽  
Non Destructive ◽  
Non Destructive Techniques

<p>The diagnosis of the conservation state of monumental structures from constraints to the spatial distribution of their physical properties on shallow and inner materials represents one of the key objectives in the application of non-invasive techniques. <em>In situ</em>, CRP and 3D ultrasonic tomography can provide an effective coverage of stone materials in space and time. The intrinsic characteristics of the materials that make up a monumental structure and affect the two properties (i.e., reflectivity, longitudinal velocity) through the above methods substantially differ. Consequently, the content of their information is mainly complementary rather than redundant.</p><p>In this study we present the integrated application of different non-destructive techniques i.e., Close Range Photogrammetry (CRP), and low frequency (24 KHz) ultrasonic tomography complemented by petrographycal analysis based essentially on Optical Microscopy (OM). This integrated methodology has been applied to a Carrara marble column of the <em>Basilica of San Saturnino</em>, in Byzantine-Proto-Romanesque style, which is part of the Paleo Christian complex of the V-VI century. This complex also includes the adjacent Christian necropolis in the square of <em>San Cosimo</em> in the city of Cagliari, Sardinia, Italy. The column under study is made of bare material dating back probably to the first century A.D., it was subjected to various traumas due to disassembly and transport to the site, including damage caused by the close blast of a WWII fragmentation bomb.</p><p>High resolution 3D modelling of the studied artifact was computed starting from the integration of proximal sensing techniques such as CRP based on Structure from Motion (SfM), with which information about the geometrical anomalies and reflectivity of the investigated marble column surface was obtained. On the other hand, the inner parts of the studied body were successfully inspected in a non-invasive way by computing the velocity pattern of the ultrasonic signal through the investigated materials using 3D ultrasonic tomography. This technique gives information on the elastic properties of the material related with mechanical properties and a number of factors, such as presence of fractures, voids, and flaws. Extracting information on such factors from the elastic wave velocity using 3D tomography provides a non-invasive approach to analyse the property changes of the inner material of the ancient column. The integrated application of <em>in situ</em> CRP and ultrasonic techniques provides a full 3D high resolution model of the investigated artifact. This model enhanced by the knowledge of the petrographic characteristics of the materials, improves the diagnostic process and affords reliable information on the state of conservation of the materials used in the construction processes of the studied monumental structure. The integrated use of the non-destructive techniques described above also provides suitable data for a possible restoration and future preservation.</p><p><strong> </strong></p><p><strong>Acknowledgments: </strong>This work was partially supported by FIR (Fondi integrativi per la Ricerca) funded by the University of Cagliari (Italy). The authors would also like to thank the Ministero dei Beni e delle Attività Culturali. Polo Museale della Sardegna and Arch. Alessandro Sitzia for their kind permission to work on the <em>San Saturnino Basilica</em>.</p>

Non-destructive techniques applied to in situ study of Maqsura at Cordoba cathedral (Spain)

2019 ◽  
pp. 338-342
Author(s):  
A. Gómez-Moron ◽  
P. Ortiz ◽  
R. Ortiz ◽  
J. Becerra ◽  
R. Gómez-Cañada ◽  
...  
Keyword(s):  
In Situ Study ◽  
Non Destructive ◽  
Non Destructive Techniques

scholarly journals Analysis of the Applicability of Non-Destructive Techniques to Determine In Situ Thermal Transmittance in Passive House Façades

2020 ◽  
Vol 10 (23) ◽  
pp. 8337
Author(s):  
Blanca Tejedor ◽  
Kàtia Gaspar ◽  
Miquel Casals ◽  
Marta Gangolells
Keyword(s):  
Co2 Reduction ◽  
Destructive Testing ◽  
Passive House ◽  
Thermal Transmittance ◽  
Detached House ◽  
Passive Houses ◽  
Actual Energy Consumption ◽  
Non Destructive ◽  
Non Destructive Techniques

Within the European framework, the passive house has become an essential constructive solution in terms of building efficiency and CO2 reduction. However, the main approaches have been focused on post-occupancy surveys, measurements of actual energy consumption, life-cycle analyses in dynamic conditions, using simulation, and the estimation of the thermal comfort. Few studies have assessed the in situ performance of the building fabric of passive houses. Hence, this paper explores the applicability of non-destructive techniques—heat flux meter (HFM) and quantitative infrared thermography (QIRT)—for assessing the gap between the predicted and actual thermal transmittance of passive house façades under steady-state conditions in the Mediterranean climate. Firstly, the suitability of in situ non-destructive techniques was checked in an experimental mock-up, and, subsequently, a detached house was tested in the real built environment. The findings revealed that both Non-Destructive Testing (NDT) techniques allow for the quantification of the gap between the design and the actual façades U-value of a new passive house before its operational stage. QIRT was faster than the HFM technique, although the latter was more accurate. The results will help practitioners to choose the most appropriate method based on environmental conditions, execution of the method, and data analysis.

In situ assessment of structural timber using non-destructive techniques

2013 ◽  
Vol 47 (5) ◽  
pp. 749-766 ◽  
Author(s):  
Mariapaola Riggio ◽  
Ronald W. Anthony ◽  
Francesco Augelli ◽  
Bohumil Kasal ◽  
Thomas Lechner ◽  
...  
Keyword(s):  
Structural Timber ◽  
In Situ Assessment ◽  
Non Destructive ◽  
Non Destructive Techniques
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