scholarly journals Development of Devices for the System of Monitoring the Strength Features of Concrete in Operated Buildings and Structures Based on the Ultrasonic Pulse Method

2019 ◽  
pp. 22-27
Author(s):  
Ya. Serikov
Keyword(s):  
Building Materials ◽  
Pulse Method ◽  
Ultrasonic Pulse ◽  
Technical Condition ◽  
Structural Elements ◽  
Survey Results ◽  
Static And Dynamic Loads ◽  
Object Material ◽  
Negative Factors

  Operation of buildings and structures for various purposes is accompanied by an impact on their structural elements, building materials, and a complex of negative factors. These factors include the lifespan, climatic parameters, static and dynamic loads, dustiness, air pollution, etc. Their action worsens the physico-mechanical characteristics, the structure of concrete. This reduces the reliability of structural elements, reduces the life of the construction object. In DBN V. 1.2-14-2009 «The system of ensuring the reliability and safety of construction objects» set the classification of construction objects by classes of consequences in the event of an accident. The estimated lifetimes of each type of construction objects are also determined. Extension of life is allowed only after inspection and evaluation of the technical condition of the construction object, material characteristics, through the determination of the degree of their compliance with regulatory requirements. The importance of obtaining reliable survey results requires the improvement of relevant instruments and metrology. The described developed system of monitoring of construction objects, as well as instrumentation and system based on the ultrasonic pulse method. They are designed to control the physico-mecha-nical characteristics, the structure of concrete and other building materials. The developed devices and system are characterized by increased accuracy, reliability and reliability of measurements.

To the Problems of Determination of Dynamic Elasticity Modules of Calcium Silicate Bricks by Means of Resonance Method

2014 ◽  
Vol 897 ◽  
pp. 139-143 ◽  
Author(s):  
Jiří Brožovský ◽  
Ámos Dufka
Keyword(s):  
Modulus Of Elasticity ◽  
Calcium Silicate ◽  
Building Materials ◽  
Resonance Method ◽  
Pulse Method ◽  
Ultrasonic Pulse ◽  
Test Methods ◽  
Test Method ◽  
Resonance Test ◽  
Accuracy Of Measurement

Modulus of elasticity of building materials can be determined in a static way (loading in a press) or by means of non-destructive test methods (ultrasonic pulse method and resonance method); the parameter is most frequently determined for concrete and both methods of determining elasticity modulus are codified in Standards. Elasticity characteristics of calcium silicate bricks were determined by means of resonance test method. Because the shape of calcium silicate bricks (a block with oblong foot) is different from the shape of test specimens for concrete (usually blocks with square foot), expected frequencies for verification of accuracy of measurement by resonance method were determined. Moisture content of calcium silicate bricks (water absorbing capacity is up to 12-14%) has influence on the value of resonance frequency. Difference between dynamic Young's modulus of elasticity from fundamental longitudinal and transverse resonant frequency is on average 2.8%.

scholarly journals THE ALGORITHM OF COMPLEX DIAGNOSTICS OF TECHNICAL CONDITION OF BUILDING STRUCTURES ON THERMOGRAMS ANALYSIS

2020 ◽  
pp. 23-28
Author(s):  
D. Karpov
Keyword(s):  
Construction Projects ◽  
Thermal Power ◽  
Technical Condition ◽  
Building Structures ◽  
Structural Elements ◽  
Highly Qualified ◽  
Energy Survey ◽  
Measurement Base ◽  
Actual Mass

the algorithm of complex diagnostics of a technical condition of building constructions and structures on the analysis of thermograms is offered. An attempt is made to systematize and logically build a sequence of stages of energy inspection of heat-consuming and heat-generating construction projects and their structural elements. The presented algorithm includes the main stages performed in such surveys. It differs from the known technologies of energy monitoring of buildings and structures by the presence of two additional stages, which are an integral part of any energy survey: determination of the relative surface humidity of building structures and the actual mass flow of coolant through the heating device for the analysis of thermal images. The implementation of energy (thermal imaging) and technical inspections according to the presented structural scheme requires not only the presence of appropriate instrumentation and measurement base, but also the involvement of highly qualified specialists (civil engineers, thermal power engineers, thermal physicists, operators-thermographers, etc.).

scholarly journals Nalysis of Changes to Steel Footbridge Geometry Within 25 Years in Service

2018 ◽  
Vol 28 (2) ◽  
pp. 164-176
Author(s):  
Jacek Sztubecki ◽  
Adam Bujarkiewic ◽  
Justyna Sobczak-Piąstka ◽  
Tomasz Janiak ◽  
Jarosław Gajewski
Keyword(s):  
Service Life ◽  
Technical Condition ◽  
Frame Of Reference ◽  
General Analysis ◽  
Bridge Structure ◽  
Structural Elements ◽  
Bridge Structures ◽  
Special Value ◽  
Static Operation

Abstract Identification of the technical condition of bridge structures should be supplemented by determination of structural displacements in relation to the adopted frame of reference and measurement of changes to the geometry of its individual elements. Of special value are the results of measurements of the same values obtained along an extended service life. They provide an opportunity to compare results, track down tendencies, and more quickly recognise signs of aggravating technical condition of structures. The paper presents an analysis of changes to the geometry of a bridge structure – a cable– stayed footbridge used for pedestrian and bicycle traffic across the Brda river in Bydgoszcz. Measurements were made by means of surveying techniques within a period of 25 years of the structure service life. The collected data enabled numerous comparative analyses to be conducted. Displacements of footbridge structural elements observed across time led to formulation of recommendations for further use of the footbridge. For instance, recommendations for footbridge adjustment, including improvement of its geometry, were provided. In addition, a general analysis of the effect of footbridge displacements on its static operation was conducted.

scholarly journals DETERMINATION OF TECHNICAL CONDITION OF BUILDING CONSTRUCTIONS BASED ON COMPREHENSIVE ASSESSMENT OF BUILDING PRODUCTION

2019 ◽  
pp. 22-27
Author(s):  
А. Малахов ◽  
A. Malahov ◽  
В. Косинов ◽  
Viktor Kosinov
Keyword(s):  
Technical Condition ◽  
Comprehensive Assessment ◽  
Structural Elements ◽  
Industrial Facilities ◽  
Engineering Research ◽  
Industrial Buildings ◽  
Metal Frame ◽  
Capital Construction ◽  
Instrumental Control

The article deals with the issues related to the assessment of the technical condition of structural elements, taking into account the stages of engineering research, design and installation. The importance of the topic under consideration is due to a large number of accidents at civil and industrial facilities that occur before the exhaustion of the bearing capacity. The analysis of the object (the metal frame of industrial buildings) is carried out on the basis of project documentation, data obtained by a full-scale survey, visual and instrumental control, numerical methods of research. The qualitative and quantitative parameters of the capital construction object necessary for assessing the technical condition are presented. They include design schemes of frame structures, materials, their characteristics, defects and parameters. The study shows the importance of comprehensive assessment of capital construction facilities in terms of constructive safety. Identification of errors at each stage of construction allows to prevent emergencies that lead to the destruction of the load-bearing system and to develop measures to establish the possibility (impossibility) of repair or reconstruction

Mechanical and Durability Properties of Selected Types of Sandstones

2016 ◽  
Vol 827 ◽  
pp. 324-327
Author(s):  
Pavel Reiterman ◽  
Ondřej Holčapek
Keyword(s):  
Main Part ◽  
Material Parameter ◽  
Pulse Method ◽  
Ultrasonic Pulse ◽  
Non Destructive Testing ◽  
Porous Rocks ◽  
Destructive Testing ◽  
Water Absorption Test ◽  
Non Destructive

Present paper is focused on the experimental assessment of three sandstones from different quarries. Mechanical testing was carried out besides water absorption test and determination of frost resistance what is the crucial material parameter for all types of porous rocks. Gradual deterioration due to action of frost was monitored using non-destructive testing – ultrasonic pulse method. Obtained results well describe failure mechanism of studied sandstones of different basic physical properties. It was conducted that main part of deterioration was performed at the beginning of the freeze-thaw cycling.

Analysis of Relations for Determination of Parameters of Various Types of Concrete Based on Ultrasonic Pulse Method Measurement

2014 ◽  
Vol 923 ◽  
pp. 99-107
Author(s):  
Jiří Brožovský ◽  
Jiří Bydžovský
Keyword(s):  
High Performance ◽  
Pulse Propagation ◽  
Pulse Method ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Normal Weight ◽  
Technical Literature ◽  
Determination Of Parameters

It is often necessary to determine strength of concrete (Normal-weight, High-performance and Light-Weight) in the structure. To determine strength, ultrasonic pulse method is used. However, the basic condition of its effective use is existence of relations between velocity of ultrasonic pulse propagation and strength. These relations are elaborated for normal weight concrete in great extent. However, for other types of concrete, relations for determination of strength on the basis of ultrasonic pulse velocity are stated in technical literature and their practical applicability could be questioned. The paper gives analysis of such relations from the point of view of practical applicability for determination of parameters of concrete built in a structure.

scholarly journals Determine the Compressive Strength of Calcium Silicate Bricks by Combined Nondestructive Method

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Jiri Brozovsky
Keyword(s):  
Compressive Strength ◽  
Calcium Silicate ◽  
Pulse Method ◽  
Close Correlation ◽  
Ultrasonic Pulse ◽  
Nondestructive Method ◽  
Production Plant ◽  
Rebound Hammer ◽  
Schmidt Rebound Hammer

The paper deals with the application of combined nondestructive method for assessment of compressive strength of calcium silicate bricks. In this case, it is a combination of the rebound hammer method and ultrasonic pulse method. Calibration relationships for determining compressive strength of calcium silicate bricks obtained from nondestructive parameter testing for the combined method as well as for the L-type Schmidt rebound hammer and ultrasonic pulse method are quoted here. Calibration relationships are known for their close correlation and are applicable in practice. The highest correlation between parameters from nondestructive measurement and predicted compressive strength is obtained using the SonReb combined nondestructive method. Combined nondestructive SonReb method was proved applicable for determination of compressive strength of calcium silicate bricks at checking tests in a production plant and for evaluation of bricks built in existing masonry structures.

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