scholarly journals Mechanical Properties of Historic Masonry Stones Obtained by In Situ Non-Destructive Tests on the St. Agostino Church in Amatrice (Italy)

2021 ◽  
Vol 11 (14) ◽  
pp. 6352
Author(s):  
Alessandro Grazzini ◽  
Giuseppe Lacidogna
Keyword(s):  
Laboratory Tests ◽  
Mechanical Characteristics ◽  
Central Italy ◽  
Historic Masonry ◽  
Non Invasive ◽  
Impact Tests ◽  
Mechanical Strengths ◽  
The Impact ◽  
Non Destructive

The design of strengthening and securing work for historic buildings requires knowledge of the masonry mechanical characteristics, often obtainable through laboratory tests that require invasive samples. The non-destructive techniques, applicable in situ in a rapid and non-invasive way, represent a valid alternative to estimate mechanical strengths without destructive sampling. In this study, a methodology was calibrated which, by combining the results of the ultrasonic and impact tests, makes it possible to reach a good estimate of the compression strength and elastic modulus of a particular rock: sandstone. Most buildings in Amatrice, the city devastated by the violent earthquake of Central Italy in 2016, were built by means of this sedimentary rock. By carrying out a diagnostic campaign on the remaining walls of the St. Agostino church in Amatrice, it was possible to obtain a correlation, specific for this case study, between the compression strengths from laboratory tests and the results of the ultrasonic and impact tests. Unlike the traditional Sonreb methods, this methodology wanted to favor the use of the impact method instead of the sclerometrer test. In this way, it will be possible to operate on other damaged buildings of similar construction types located in the seismic crater of Amatrice, evaluating the mechanical characteristics of the masonry structures be means of in situ non-destructive tests in order to design the safety and strengthening work.

Load-Bearing Capacity Determination of Historic Masonry Structures

2014 ◽  
Vol 923 ◽  
pp. 81-84 ◽  
Author(s):  
Jiří Witzany ◽  
Tomáš Čejka ◽  
Radek Zigler
Keyword(s):  
Mechanical Characteristics ◽  
Masonry Wall ◽  
Probabilistic Methods ◽  
Laboratory Research ◽  
Historic Masonry ◽  
Historical Masonry ◽  
Non Destructive ◽  
Physical And Mechanical Characteristics

The experimental, in-situ and laboratory research has manifested a relatively large variance of the physical and mechanical characteristics of historical masonry found e.g. within a masonry wall, a massive masonry pillar etc. Artical presents the evaluation of the experimentally determined physical and mechanical characteristics of masonry members and the binder obtained by sampling specimens and by non-destructive measurements relies on the application of appropriate probabilistic methods.

scholarly journals Effect of In-Situ Synthesized Boride Phases on the Impact Behavior of Iron-Based Composites Reinforced by B4C Particles

Metals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 554
Author(s):  
Fehmi Nair ◽  
Mustafa Hamamcı
Keyword(s):  
Contact Forces ◽  
Impact Behavior ◽  
Iron Matrix ◽  
Impact Tests ◽  
B4c Particles ◽  
Iron Based ◽  
In Situ Reactions ◽  
Boride Phases ◽  
The Impact

The objective of this study is to investigate the impact behavior of iron-based composites reinforced with boron carbide (B4C) particles and in-situ synthesized iron borides (Fe2B/FeB). The composite specimens (Fe/B4C) were fabricated by hot-pressing under a pressure of 250 MPa at 500 °C, and sintered at a temperature of 1000 °C. The effects of the reinforcement ratio on the formation of in-situ borides and impact behavior were investigated by means of different volume fractions of B4C inside the iron matrix: 0% (un-reinforced), 5%, 10%, 20%, and 30%. Drop-weight impact tests were performed by an instrumented Charpy impactor on reinforced and un-reinforced test specimens. The results of the impact tests were supported with microstructural and fractographical analysis. As a result of in-situ reactions between the Fe matrix and B4C particles, Fe2B phases were formed in the iron matrix. The iron borides, formed in the iron matrix during sintering, heavily affected the hardness and the morphology of the fractured surface. Due to the high amount of B4C (over 10%), porosity played a major role in decreasing the contact forces and fracture energy. The results showed that the in-situ synthesized iron boride phases affect the impact properties of the Fe/B4C composites.

scholarly journals NDT ASSESSMENT OF EXISTING CONCRETE STRUCTURES: SPATIAL ANALYSIS OF REBOUND HAMMER RESULTS RECORDED IN-SITU

2015 ◽  
Vol 7 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Adorján Borosnyói
Keyword(s):  
Spatial Analysis ◽  
Surface Hardness ◽  
Hardness Measurement ◽  
Optical Recording ◽  
Destructive Testing ◽  
Rebound Hammer ◽  
Schmidt Rebound Hammer ◽  
The Impact ◽  
Non Destructive

A comparative spatial analysis of surface hardness of structural concrete is introduced. Main objective of the paper is to make a repeatability comparison of three types of the still most popular non-destructive testing devices for concrete: L-type original Schmidt rebound hammer, N-type original Schmidt rebound hammer and N-type Silver Schmidt rebound hammer. Results indicate that the surface hardness measurement uncertainty is related to the weight of the hammer mass and is apparently not related to the impact energy of the rebound hammer devices. It is observed that the measure of surface hardness for the Silver Schmidt rebound hammer (Q-value) does not have positive correlation to the original rebound index (R). Results indicate the best performance of the N-type original Schmidt rebound hammer in terms of stability and normality of data. Geostatistical analysis of the measured data (in terms of empirical semivariograms) highlights different statistical behaviour for the mechanical recording rebound hammers and for the electro-optical recording rebound hammer.

scholarly journals NDT Methods Suitable for Evaluation the Condition of Military Fortification Construction in the Field

2020 ◽  
Vol 10 (22) ◽  
pp. 8161
Author(s):  
Zezulová Eva ◽  
Hasilová Kamila ◽  
Komárková Tereza ◽  
Stoniš Patrik ◽  
Štoller Jiří ◽  
...  
Keyword(s):  
Residual Strength ◽  
Fiber Reinforced Concrete ◽  
Protective Structure ◽  
Steel Fiber Reinforced Concrete ◽  
Degree Of Damage ◽  
Materials Used ◽  
Protective Structures ◽  
The Impact ◽  
Non Destructive

The protective structure is designed to protect the live force against the impact of a shock wave and projectiles, it cannot be diagnosed by the destructive method which devalues the protective structure by sampling. The authors are looking for a combination of suitable non-destructive technology (NDT) methods that would be used in the future to prove the degree of damage to cement-based protective structures after an explosion. This article represents the first part of an experiment designed to verify the applicability of NDT methods, to evaluate the degree of damage of the protective structure in the field. The experiment consists of three parts. The first part is a laboratory verification of the initial material characteristics of the materials used. The first test set of structural elements is made of steel fiber-reinforced concrete. The elements are evaluated using NDT methods and for comparison by destructive laboratory methods. The second part is the impact of structures using explosion and evaluation of the condition of structures using NDT methods in the field. The last part is used to verify the results of the NDT method, which ensures the residual strength of the structure in the laboratory and try to find the relationship between changes in the results of NDT methods and the residual strength. Radiography was included in the introductory and concluding parts of the experiment to verify the results. Although this method is not suitable for using in-situ, it is the only standardized method of the NDT methods used.

The Use of Laboratory-Measured and Strain-Gauge Backcalculated Asphalt Stiffness for Rutting Performance Prediction

2019 ◽  
Vol 2673 (3) ◽  
pp. 323-333
Author(s):  
Erdem Coleri ◽  
John T. Harvey
Keyword(s):  
Performance Prediction ◽  
Strain Gauge ◽  
Asphalt Concrete ◽  
Laboratory Tests ◽  
Concrete Materials ◽  
Long Term Performance ◽  
Term Performance ◽  
The Impact

Laboratory tests are conducted with asphalt concrete materials to determine the expected in-situ performance. In addition, laboratory test results are commonly used in mechanistic-empirical design methods for material characterization to improve the predictive accuracy of the models. However, the effectiveness of laboratory tests in characterizing the long-term performance of asphalt concrete materials needs to be validated to be able to use the results for pavement design and long-term performance prediction. Inaccurate performance characterization and prediction can directly affect the decision-making process for pavement maintenance, rehabilitation, and reconstruction and result in unexpected early failures in the field. The major objective of this study is to determine the impact of using laboratory-measured asphalt stiffness on the prediction accuracy of mechanistic-empirical models. In addition, the effect of using linear-elastic modeling assumptions (layered elastic theory) and neglecting the nonlinearity of pavement response at high load levels (and/or at high strain levels for weaker structures) on the predicted rutting performance was determined. In this study, the effectiveness of the use of laboratory asphalt stiffness tests for in-situ asphalt stiffness characterization was determined by comparing the rutting performance predicted using laboratory-measured stiffness to rutting predicted using strain-gauge backcalculated stiffness. It was determined that laboratory tests are able to characterize the in-situ stiffness characteristics of the asphalt mix used in this study and the stiffness characterization process suggested in this study can provide reliable rutting performance predictions. Results of this study are only applicable to tested rubberized asphalt concrete mixtures.

scholarly journals Smart Portable Devices Suitable for Cultural Heritage: A Review

Sensors ◽  
2018 ◽  
Vol 18 (8) ◽  
pp. 2434 ◽  
Author(s):  
Federica Valentini ◽  
Andrea Calcaterra ◽  
Simonetta Antonaroli ◽  
Maurizio Talamo
Keyword(s):  
Cultural Heritage ◽  
Communication Technology ◽  
Wireless Transmission ◽  
Portable Devices ◽  
Technological Evolution ◽  
Non Invasive ◽  
Portable Sensor ◽  
Non Destructive ◽  
Contact Sensors

This article reviews recent portable sensor technologies to apply in the Cultural Heritage (CH) fields. The review has been prepared in the form of a retrospective description of the sensor’s history and technological evolution, having: new nanomaterials for transducers, miniaturized, portable and integrated sensors, the wireless transmission of the analytical signals, ICT_Information Communication Technology and IoT_Internet of Things to apply to the cultural heritage field. In addition, a new trend of movable tattoo sensors devices is discussed, referred to in situ analysis, which is especially important when scientists are in the presence of un-movable and un-tangible Cultural Heritage and Art Work objects. The new proposed portable contact sensors (directly applied to art work objects and surfaces) are non-invasive and non-destructive to the different materials and surfaces of which cultural heritage is composed.

scholarly journals An imaging and spectroscopic methodology for in situ analysis of ceiling and wall decorations in Colonial missions in Northern Mexico from XVII to XVIII centuries

2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Edgar Casanova-González ◽  
Miguel Ángel Maynez-Rojas ◽  
Alejandro Mitrani ◽  
Isaac Rangel-Chávez ◽  
María Angélica García-Bucio ◽  
...  
Keyword(s):  
Fiber Optics ◽  
Infrared Imaging ◽  
Spanish Colonial ◽  
X Ray ◽  
Northern Mexico ◽  
Non Invasive ◽  
Materials Used ◽  
Non Destructive

Abstract Almost three hundred Spanish colonial missions—or their remains—are scattered over the vast state of Chihuahua in northern Mexico. A few of them still display painted decorations on the wood ceilings and walls. The decorated areas vary greatly, from the whole ceiling of the main aisle to just a few square meters in a lateral chapel, and so does the conservation state of the paintings. In this context, the information regarding the paintings’ composition plays a key role in the restoration and conservation processes. For the gathering of such information, we propose a combined methodology for a fast, non-destructive and non-invasive characterization of such paintings with a minimum of techniques. This methodology includes false color infrared imaging as a first approach to determine the composition of large areas of the paintings and the homogeneity of the materials used in the painted areas, followed by small area analysis by X-ray fluorescence and fiber-optics reflectance spectroscopy. This methodology was applied to characterize the elemental and molecular composition of the decorations for four missions in Chihuahua in a fast and specific manner, revealing the use of a mix of mineral and organic materials including indigo and cochineal, and detecting differences between the missions. The methodology presented here can be easily applied for the study of a wider number of missions in Chihuahua and other regions to provide outstanding information of materials, pictorial techniques and deterioration conditions.

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>

scholarly journals In Situ Analysis of Plaster Detachment by Impact Tests

2019 ◽  
Vol 9 (2) ◽  
pp. 258 ◽  
Author(s):  
Alessandro Grazzini
Keyword(s):  
In Situ Analysis ◽  
Experimental Methodology ◽  
Historical Buildings ◽  
Architectural Heritage ◽  
Impact Tests ◽  
Innovative Technique ◽  
Non Destructive

The frescoed surfaces of historical buildings may be subject to detachment due to various causes of deterioration. A new non-destructive experimental methodology is described to assess in situ the safety against plaster detachments from historical wall surfaces. Through small and punctual impacts exerted with a specific hammer on the plastered surface it is possible to evaluate the level of the plaster’s detachment. A case study at Palazzo Birago in Turin (Italy) is described to give an example of the application of this innovative technique on frescoed surfaces of historical vaults. The test allows to evaluate the safety of frescoed decorations without affecting the material consistency or creating damage, therefore, making it very suitable in the field of architectural heritage.

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