Effect of Thermal Loading on Selected Parameters of Reinforced Concrete Obtained by Acoustic NDT Method

2019 ◽  
Vol 296 ◽  
pp. 131-136
Author(s):  
Iveta Plšková ◽  
Michal Matysík ◽  
Zdeněk Chobola
Keyword(s):  
Reinforced Concrete ◽  
Thermal Loading ◽  
Acoustic Method ◽  
Frequency Spectra ◽  
Impact Echo ◽  
Steel Reinforced Concrete ◽  
Before And After ◽  
Non Destructive ◽  
Impact Echo Method ◽  
Dominant Frequencies

The paper presents the results of experiments carried out on test samples made from reinforced concrete. Within this experiment, concrete beams with steel reinforcement in the middle were made. The concrete samples were tested by a non-destructive acoustic Impact-echo method before and after high temperature loading (after cooling to room temperature). We focused on the dominant frequencies shift in the frequency spectra obtained by this method. The aim was to assess the ability of aforementioned acoustic method to detect the thermal damage of steel reinforced concrete.

The Corrosion Status of Reinforced Concrete Structure Monitoring by Impact-Echo Method

2014 ◽  
Vol 875-877 ◽  
pp. 445-449 ◽  
Author(s):  
Kristýna Šamárková ◽  
Zdeněk Chobola ◽  
Daniela Štefková
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beam ◽  
Reinforced Concrete Beam ◽  
Reinforced Concrete Structure ◽  
Response Signal ◽  
Nacl Solution ◽  
Impact Echo ◽  
Structure Monitoring ◽  
Impact Echo Method ◽  
Dominant Frequencies

The paper deals with the study of dominant frequencies of an Impact-Echo method response signal obtained from a reinforced concrete beam with a steel rod diameter of 8 mm. Tension pulse was produced in axis of the rod at one end and detected in axis at opposite end of rod. Dominant frequencies of the response signal will be the main criterions for the reinforced concrete rebar corrosion progress. The article presents the results of measurements obtained after 12 months controlled degradation in aqueous NaCl solution. The results were compared with measurements of electrical resistance of reinforcing steel by using the Thomson double bridge.

Impact-Echo Method for Non-Destructive Testing of High-Temperature-Degraded Cement-Based Composite

2015 ◽  
Vol 1124 ◽  
pp. 301-306
Author(s):  
Daniela Štefková ◽  
Kristýna Timcakova ◽  
Zdeněk Chobola
Keyword(s):  
High Temperature ◽  
Acoustic Analysis ◽  
Heat Exposure ◽  
Acoustic Method ◽  
High Temperature Treatment ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Impact Echo ◽  
Non Destructive ◽  
Impact Echo Method

Non-destructive acoustic analysis method Impact-echo method as a traditional method for civil engineering was used for this experiment. The paper deals with the applicability of Impactecho acoustic method to testing of cement-based composites prepared from a mix of cement mortar and quartz sand, which were intentionally degraded by high-temperature treatment (in the temperatures range from 200°C to 1200°C). The aim of this paper is introduce the effect of high-temperature degradation. An understanding of microstructure performance relationships is the key to true understanding of material behaviors. The results of non-destructive testing confirmed the different structure of mortar specimens. The subjected to high-temperatures led to absorption of lower frequencies as compared to the reference specimens. A significant decrease of the absorbed frequencies was observed, depending on temperature. The largest decrease occurred after the specimens exposure at 400-600 °C. The effect of heat exposure to the decrease of frequencies was mitigated to the temperature degradation 1200 °C.

Monitoring of Reinforced Concrete Structure Corrosion by Using Impact-Echo Method

2014 ◽  
Vol 1000 ◽  
pp. 239-242 ◽  
Author(s):  
Kristýna Šamárková ◽  
Daniela Štefková ◽  
Zdeněk Chobola
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beam ◽  
Acoustic Method ◽  
Reinforced Concrete Beam ◽  
Dominant Frequency ◽  
Reinforced Concrete Structure ◽  
Main Criterion ◽  
Impact Echo ◽  
Opposite Position ◽  
Impact Echo Method

This study deals with frequency inspection of response signal which was obtained from a reinforced concrete beam. Impact-Echo method was used for finding the dominant frequency which is the main criterion for condition assessment of reinforced concrete. The results of acoustic method were compared with measurements of electrical resistance of reinforcing steel by using the Thomson double bridge. The concrete beam with a steel rod diameter of 6 mm was tested. Tension pulse was produced in the centre of the concrete beam and detected in opposite position of the concrete beam.

Using of Impact-Echo Methods to Assessment of Reinforced Concrete Structures Corrosion

2013 ◽  
Vol 446-447 ◽  
pp. 1400-1404 ◽  
Author(s):  
Kristýna Šamárková ◽  
Zdeněk Chobola ◽  
Daniela Štefková
Keyword(s):  
Reinforced Concrete ◽  
Electrical Resistance ◽  
Concrete Beam ◽  
Reinforced Concrete Beam ◽  
Response Signal ◽  
Nacl Solution ◽  
Impact Echo ◽  
Rebar Corrosion ◽  
Impact Echo Method ◽  
Dominant Frequencies

The paper deals with the study of dominant frequencies of an Impact-Echo method response signal obtained from a reinforced concrete beam with a steel rod diameter of 8 mm. Tension pulse was produced in axis of the rod at one end and detected in axis at opposite end of rod. Dominant frequencies of the response signal will be the main criterions for the reinforced concrete rebar corrosion progress. The article presents the results of measurements obtained after 12 months controlled degradation in aqueous NaCl solution. The results were compared with measurements of electrical resistance of reinforcing steel by using the Thomson double bridge.

scholarly journals Analyzing of Coatings on Steel - Reinforced Concrete Elements by Mobile NMR

2016 ◽  
Vol 62 (1) ◽  
pp. 65-82 ◽  
Author(s):  
J. Orlowsky
Keyword(s):  
Reinforced Concrete ◽  
Potential Effect ◽  
Building Site ◽  
Steel Reinforced Concrete ◽  
Mobile Nmr ◽  
The Individual ◽  
First Time ◽  
Concrete Elements ◽  
Non Destructive

Abstract A large number of infrastructural concrete buildings are protected against aggressive environments by coating systems. The functionality of these coating systems is mainly affected by the composition and thickness of the individual polymeric layers. For the first time ever, a mobile nuclear magnetic resonance (NMR) sensor allows a non-destructive determination of these important parameters on the building site. However, before this technique can be used on steel-reinforced concrete elements, the potential effect of the reinforcement on the measurement, i.e. the NMR signal, needs to be studied. The results show a shift of the NMR profile as well as an increase of the signals amplitude in the case of the reinforced samples, while calculating the thickness of concrete coating leading to identical results.

Estimation of Impact-Echo Method for the Assessment of Long-Term Frost Resistance of Ceramic Tiles

2014 ◽  
Vol 1000 ◽  
pp. 285-288 ◽  
Author(s):  
Michal Matysík ◽  
Iveta Plšková ◽  
Zdeněk Chobola
Keyword(s):  
Frost Resistance ◽  
Surface Condition ◽  
Acoustic Method ◽  
Ceramic Tiles ◽  
Impact Echo ◽  
Thaw Cycle ◽  
Freeze Thaw Cycle ◽  
Confocal Scanning ◽  
The Impact ◽  
Impact Echo Method

The aim of this paper is to evaluate the possibility of using the Impact-echo method for assessment of extremely long period of frost resistance of ceramic tiles. Sets of ceramic tiles of the Ia class to EN 14 411 B standard made by manufacture RACOs have been analyzed. The ceramic tiles under investigation have been subjected to 500 freeze-thaw-cycle based degradation in compliance with the relevant EN ISO 10545-12 standard. To verify the correctness of the Impact-echo method results, additional physical properties of the ceramic tiles under test have been measured. To analyze the specimen surface condition, we also used Olympus LEXT 3100 confocal scanning microscope. It has been proved that the acoustic method Impact-echo is a sensitive indicator of the structure condition and can be applied to the ceramic cladding element frost resistance and service life prediction assessment.

Estimation of Thickness of Concrete Slab Members Using Impact Echo Method

2014 ◽  
Vol 605 ◽  
pp. 139-142
Author(s):  
Seong Uk Hong ◽  
Yong Taeg Lee ◽  
Seung Hun Kim ◽  
J.H. Na
Keyword(s):  
Concrete Slab ◽  
Hardness Test ◽  
Pulse Velocity ◽  
Non Destructive Testing ◽  
Testing Methods ◽  
Destructive Testing ◽  
Impact Echo ◽  
Maintenance And Repair ◽  
Non Destructive ◽  
Impact Echo Method

Recently, the interest in maintenance and repair of existing concrete structures have increased, and it is typical to use non-destructive testing methods such as rebound hardness test or ultrasonic pulse velocity method to execute maintenance and repair of structures efficiently. Many non-destructive testing methods are being used in practice such as at construction sites, but verification for site applications are quite inadequate. Thus, this study intends to evaluate the applicability of Impact Echo Method which is one of the non-destructive testing methods using stress wave. Total of four specimens were planned and produced. The thickness of concrete slab members was estimated using I.E(OLSENs Freedom Data PC with Win.TFS Software Version 2.5.2). The estimated materials of concrete members by IE was found to be IE-1 specimen 178mm, IE-2 specimen 197mm, IE-3 specimen 191mm, and IE-4 specimen 263mm, and the error rate was found to be 4.22%~18.67% (average 9.6%), showing that they are relatively well in agreement. In this study, the experiments were executed with the objective of estimating the thickness of concrete slab members using Impact Echo Method. Through this study, the applicability of thickness estimation in concrete slab members using impact echo method could be confirmed.

Estimation of Depth of Concrete Column Members Using Impact Echo Method

2014 ◽  
Vol 605 ◽  
pp. 194-197
Author(s):  
Seung Hun Kim ◽  
Seong Uk Hong ◽  
Yong Taeg Lee ◽  
Seung Ho Lee
Keyword(s):  
Test Methods ◽  
Test Method ◽  
Concrete Column ◽  
Ground Field ◽  
Design Strength ◽  
Impact Echo ◽  
Destructive Test ◽  
The Impact ◽  
Non Destructive ◽  
Impact Echo Method

In order to maintain the existing concrete structures in a safe and usable state, an overall maintenance management is necessary regarding structure aging from quality management of new construction. Thus, non-destructive testing is needed to estimate the structure damage, defect, or proper construction without damaging the structure. In U.S., there is a standard for non-destructive test (ACI 228.2R-98), and also in Japan, the non-destructive test method and compressive strength estimation manual was prepared by the Architectural Institute of Japan in 1983, and there are active researches in the ground field, but it lacks verification in architecture field. Thus, in this study, a technique that can estimate the depth of concrete column member using the Impact Echo method which is one of the non-destructive test methods shall be reviewed and evaluated for applicability to the architecture field. The specimen was mixed with design strength of 30MPa. The equipment used in testing is Freedom Date Pc Platform Win.TFS 2.5.2 by company Olson of U.S., and the experiment involved leveling the top surface of the concrete member, installing the equipment and applying impact 9 times, and taking the average of the reverberation values obtained. The estimated average depth of concrete column member using Impact Echo method was 304mm for IEC-300, 398mm for IEC-400, and 484mm for IEC-500, and the relative error rate compared to the actual size was 1%~3%. Through this study, the applicability of estimation of depth in concrete column members using impact echo method could be confirmed.

Determination of the Influence of Carbonation of Concrete and Corrosion of Steel on Reinforced Concrete Condition

2015 ◽  
Vol 1124 ◽  
pp. 225-230 ◽  
Author(s):  
Kristýna Timcakova ◽  
Daniela Štefková ◽  
Zdeněk Chobola
Keyword(s):  
Reinforced Concrete ◽  
Concrete Structures ◽  
Poor Quality ◽  
Protective Properties ◽  
Impact Echo ◽  
Concrete Condition ◽  
Almost All ◽  
Corrosion Of Steel ◽  
Impact Echo Method

Almost all reinforced concrete structures which are exposed to weather effects are threatened by corrosion. The corrosion of steel elements in structures has an influence on lifetime these constructions and adversely affects their properties. However, the steel in concrete structures is protected against corrosion due to the properties of concrete such as high pH or impermeability, but if the concrete is of poor quality and his protective properties are insufficient the corrosion can occur. A problem causes the action of carbon dioxide which has the effect of lowering the pH below the critical value and thereby accelerating the corrosion.Non-destructive methods such as Impact-echo method offer the possibility of easy and quickly detection of initial damage of structure and thus can prevent the occurrence of permanent damage to the whole construction.This article describes the development of corrosion which is caused by carbonation of the concrete and supported by action of chlorides by using Impact-echo method. The paper presents results obtained on the reinforced concrete samples with one steel rod passing through the center. After carbonation concrete the samples were exposed accelerated controlled degradation in aqueous NaCl solution for 4 months.

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