scholarly journals Application of the Minor Destructive Test (MDT) method for determination of AAC masonry compressive strength

2019 ◽  
Vol 91 (2) ◽  
Author(s):  
Radosław Jasiński ◽  
Łukasz Drobiec ◽  
Wojciech Mazur
Keyword(s):  
Compressive Strength ◽  
Empirical Relationship ◽  
Nominal Density ◽  
Empirical Curve ◽  
Aerated Concrete ◽  
Atmospheric Factors ◽  
The Impact ◽  
Non Destructive ◽  
Destructive Methods

Non-destructive methods (NDT) in masonry made of autoclaved aerated concrete (AAC) are not used as commonly as in concrete or reinforced concrete constructions. The porous structure and sensitivity to atmospheric factors, especially humidity, makes it necessary to determine the compressive strength of the wall in existing and used objects. The article presents a proposal of a semi-non-destructive method for determining the compressive strength of AAC, and then a wall made with thin-layer joints. An empirical curve developed for cellularconcrete with nominal density classes 400, 500, 600 and 700 in an air-dry condition was used for calibration.In addition, an empirical relationship was developed to take into account the impact of ABK moisture.

Determination of the Strength Parameters of Pinewood Based on the Non-Destructive Sclerometric Test with a Wood Hammer

2020 ◽  
Vol 30 (1) ◽  
pp. 43-52
Author(s):  
Bartosz Szostak ◽  
Maciej Trochonowicz ◽  
Mateusz Kowalczyk
Keyword(s):  
Compressive Strength ◽  
Nondestructive Testing ◽  
Technical Condition ◽  
Strength Parameters ◽  
The Impact ◽  
Non Destructive ◽  
Structure And Design

AbstractTo assess the technical condition of a structure and design it using existing elements, it is necessary to know its parameters. For existing facilities, it is often not possible to get a sample of material and examine it directly in the laboratory. For this reason, in situ nondestructive testing is very important.The main goal of the paper is to present the issues related to determining the strength parameters of a particular wood based on the non-destructive sclerometric test performed with a wood sclerometric hammer. The study also presents the results of the impact of pinewood density on its compressive strength.

Determination of a Suitable Moment for Formwork Removal from a Concrete Structure Using Rebound Hammer Test Methods

2021 ◽  
Vol 322 ◽  
pp. 23-27
Author(s):  
Petr Misák ◽  
Dalibor Kocáb ◽  
Petr Cikrle
Keyword(s):  
Compressive Strength ◽  
Characteristic Curve ◽  
Test Methods ◽  
Rebound Hammer ◽  
Practical Applications ◽  
Relevant Topic ◽  
Compressive Strength Of Concrete ◽  
The Moment ◽  
Non Destructive

Determining the compressive strength of concrete in the early stages of ageing has been an increasingly relevant topic in recent years, particularly with regard to the safe removal of formwork from a structure or its part. The compressive strength of concrete which designates safe removal of formwork without damaging the structure can be referred to as "stripping strength". It is undoubtedly beneficial to be able to determine the moment of safe formwork removal in a non-destructive manner, i.e. without compromising the structure. Modern rebound hammer test methods seem to be a suitable instrument with which it is possible to reduce the length of technological breaks associated with concrete ageing to a minimum, and consequently, reduce the total cost of the construction. However, the use of these methods presents a number of challenges. As many conducted experiments have shown, there is no single conversion relationship (regression model) between non-destructive rebound hammer test methods and compressive strength. It is therefore advisable to always create a unique conversion relationship for each individual concrete. In addition, it must be noted that conventional regression analysis methods operate with 50% reliability. In construction testing, however, the most common is the so-called characteristic value, which is defined as a 5% quantile. This value is therefore determined with 95% reliability. This paper describes the construction of a so-called "characteristic curve", which can be used to estimate the compressive strength of concrete in a structure using rebound hammer test methods with 95% reliability. Consequently, the values obtained from the characteristic curve can be easily used for practical applications.

scholarly journals Investigation of the Impact of Load on the Magnetic Field Strength of the Crane by the Magnetic Metal Memory Technique

Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5559
Author(s):  
Agnieszka Koson-Schab ◽  
Janusz Szpytko
Keyword(s):  
Residual Magnetization ◽  
Magnetic Memory ◽  
Metal Magnetic Memory ◽  
Magnetic Metal ◽  
Structural Inspection ◽  
The Impact ◽  
Non Destructive ◽  
The Magnetic Field ◽  
Flux Leakage ◽  
Destructive Methods

The paper deals with the problem of applicability of the metal magnetic memory (MMM) technique in the crane structural inspection and monitoring. The MMM method does not require the external magnetization of a structure that results in reduction of downtime of maintenance operations. Measurement of the intensity of the self-magnetic leakage signal can be an alternative to other non-destructive methods used for inspection of a large crane’s structure and equipment. However, the complexity of the residual magnetization effect in the MMM technique is the problem with its application. Thus, the magnetic flux leakage behavior on the crane girder surface under different measurements and the crane’s load conditions is analyzed based on the results obtained during experiments carried out on the overhead traveling crane.

scholarly journals Portable XRF: A Tool for the Study of Corundum Gems

2017 ◽  
Vol 3 (1) ◽  
Author(s):  
Germana Barone ◽  
Paolo Mazzoleni ◽  
Danilo Bersani ◽  
Simona Raneri
Keyword(s):  
Spectroscopic Techniques ◽  
Portable Xrf ◽  
Correct Evaluation ◽  
Non Invasive ◽  
Heritage Studies ◽  
Origin Determination ◽  
Non Destructive ◽  
Xrf Spectroscopy ◽  
Destructive Methods

AbstractOrigin of gemstones is a key aspect not only in gemological field but also in Cultural Heritage studies, for the correct evaluation of precious artifacts. The studies on gems require the application of non-invasive and non-destructive methods; among them, portable spectroscopic techniques has been demonstrated as powerful tools, providing a fingerprint of gems for origin and provenance determination. In this study, portable XRF spectroscopy has been applied to test the potential of the technique for the origin determination of corundum gems. The obtained results allowed distinguishing natural and synthetic rubies and sapphires.

scholarly journals Prediction of Compressive Strength Using Support Vector Regression

MENDEL ◽  
2019 ◽  
Vol 25 (1) ◽  
pp. 51-56
Author(s):  
Goutham J Sai ◽  
Vijay Pal Singh
Keyword(s):  
Compressive Strength ◽  
Support Vector Regression ◽  
Design Stage ◽  
Support Vector ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Study Support ◽  
Compressive Strength Of Concrete ◽  
Non Destructive

At the design stage of a structure, the members of adequate dimension and strength is provided. But with passage of time, the strength of the members reduces gradually due to exposure to environmental conditions and unexpected loadings other than for which the structure is designed. Non Destructive Testing (NDT) method provides a convenient and rapid method of determination of existing strength of concrete without subjecting the member to any damage.  In the present study, Support Vector Regression (SVR) in Python has been used for the prediction of compressive strength of concrete. Three different NDT techniques have been used as input for the SVR model. A good co-relation between predicted strength and strength determined after crushing the concrete cubes has been achieved. It has also been observed that accuracy in the predicted strength is more in case of inputs from more than one NDT technique is used.

scholarly journals Validation of Selected Non-Destructive Methods for Determining the Compressive Strength of Masonry Units Made of Autoclaved Aerated Concrete

Materials ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 389 ◽  
Author(s):  
Radosław Jasiński ◽  
Łukasz Drobiec ◽  
Wojciech Mazur
Keyword(s):  
Compressive Strength ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
P Wave ◽  
In Situ Tests ◽  
Transmission Method ◽  
Autoclaved Aerated Concrete ◽  
Aerated Concrete ◽  
Non Destructive

Minor-destructive (MDT) and non-destructive (NDT) techniques are not commonly used for masonry as they are complex and difficult to perform. This paper describes validation of the following methods: semi-non-destructive, non-destructive, and ultrasonic technique for autoclaved aerated concrete (AAC). The subject of this study covers the compressive strength of AAC test elements with declared various density classes of: 400, 500, 600, and 700 (kg/m3), at various moisture levels. Empirical data including the shape and size of specimens, were established from tests on 494 cylindrical and cuboid specimens, and standard cube specimens 100 mm × 100 mm × 100 mm using the general relationship for ordinary concrete (Neville’s curve). The effect of moisture on AAC was taken into account while determining the strength fBw for 127 standard specimens tested at different levels of water content (w = 100%, 67%, 33%, 23%, and 10%). Defined empirical relations were suitable to correct the compressive strength of dry specimens. For 91 specimens 100 mm × 100 mm × 100 mm, the P-wave velocity cp was tested with the transmission method using the ultrasonic pulse velocity method with exponential transducers. The curve (fBw–cp) for determining the compressive strength of AAC elements with any moisture level (fBw) was established. The developed methods turned out to be statistically significant and can be successfully applied during in-situ tests. Semi-non-destructive testing can be used independently, whereas the non-destructive technique can be only applied when the developed curve fbw–cp is scaled.

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