1,721,523 research outputs found
Dimensionamento aerodinamico preliminare di un velivolo UAV STOL elettrico in configurazione PrandtlPlane
No full textContratto fra Dip. di Ingegneria Aerospaziale di Pisa e Soc UTRI Triest
A laboratory multisensor geophysical approach for monitoring steel rebar corrosion in concrete structures
No full textNon-destructive monitoring methods are crucial for the management and maintenance of assets, which include reinforced concrete (RC) structures. Steel reinforcing bar (rebar) corrosion is one of the main causes of deterioration of engineered reinforced structures as it decreases their strength and serviceability. The purpose of this study was to use nondestructive geophysical techniques to detect and monitor rebar corrosion phenomena. To achieve this, several laboratory tests were performed on RC samples partially immersed in water containing a 5% of sodium chloride (NaCl) solution. Moreover, an accelerated corrosion phenomenon was produced by supplying direct current power along the rebar. Ground-penetrating radar measurements were performed on the concrete surface using 2.0 GHz centre frequency antennas, self-potential acquisitions, and electrical resistivity tomography. Even though each technique provided specific information, a data integration approach, simultaneously using different sensors, would further improve the overall quality of the diagnosis. The data set collected was used for an integrated detection approach, effective in observing the evolution of the corrosion process along the reinforcement bar. Through these laboratory results, a multisensor approach and an integrated observation proved useful for observing the evolution of corrosion phenomenon in reinforcement bars, as a consequence of the steel rebar corrosion
Soluzioni per la modifica della risposta in frequenza dell'albero del Baglioni VI serie 27 mt, della Soc. Intermarine S.p.A."
No full textDDIA 2005/8(Documento del Dipartimento di Ingegneria Aerospaziale
Combined NDT techniques in civil engineering applications: Laboratory and real test
No full textThe damage of concrete structures calls for effective methods for condition evaluation and maintenance. The usual destructive testing has many disadvantages in Civil Engineering because involves the physical destruction of specimens to evaluate mechanical and structural characteristics. On the contrary, Non Destructive Tests (NDT) are able to investigate different structures with high resolution, low time consuming and relative few costs. This resulted in development of several NDTs techniques for monitoring civil infrastructures. Accurate analysis of the physical parameters that characterize the structures is made possible by the spread of instruments that are actually more precise and economical. However, failure to use non-destructive tests effectively can be disastrous in operation of structures restoration or buildings rehabilitation. Applied geophysics is able to provide many information on the state of preservation and quality of engineering work. This work has investigated the skill of Ground Penetrating Radar (GPR) also applied in tandem with Infrared Thermography (IR) and Electrical Resistivity Tomographies (ERT) for the characterization and monitoring of building structures in laboratory and in-situ conditions. Two experimental cases are realized: in the first one GPR and ERT were performed in full scale laboratory conditions where a road segment was investigated in different conditions; in the second test, a radiant floor was investigated with comparison of results obtained with GPR and IR. The study demonstrates the feasibility of integrating the collected data obtained with non-destructive testing to enhance knowledge of engineering issues. (C) 2017 Elsevier Ltd. All rights reserved
Comparison between geological and electrical resistivity methods for salt-water subsurface surveys. the case of a channel mouth infilling in the Rhône delta
No full textComparison between geological and electrical resistivity methods for salt-water subsurface surveys. the case of a channel mouth infilling in the Rhône delt
Tomografie Geoelettriche Profonde (DERT) per lo studio geologico-idrogeologico di Ferrara
No full textLe attività di questo lavoro sono parte del Progetto CLARA e consistono nell’applicazione di un approccio 2D e 3D di Geoelettrica Profonda in aree urbane. L’applicazione di alcuni metodi geofisici permette il riconoscimento di strutture geologiche profonde. Tali metodologie si basano sullo studio delle variazioni di alcuni parametri fisici come la densità, la conducibilità elettrica, la resistività, etc., definendone la dimensione di tali strutture e i cambiamenti nella natura litologica del sottosuolo
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