Experimental Assessment Techniques for the Dynamic Properties of Concrete

2017 ◽  
Vol 21 ◽  
pp. 226-233
Author(s):  
Mihai Sergiu Stratulat ◽  
Oana Mihaela Banu ◽  
Ana Maria Toma ◽  
Petru Mihai ◽  
Ionuț Ovidiu Toma
Keyword(s):  
Dynamic Properties ◽  
Measurement Techniques ◽  
Construction Materials ◽  
Rubberized Concrete ◽  
Destructive Testing ◽  
Recycled Materials ◽  
Assessment Techniques ◽  
Standardized Measurement ◽  
The Impact ◽  
Non Destructive

Recent progress in measurement techniques have given rise to increasing interest in non-destructive testing. Incorporating non-conventional, recycled materials in concrete (i.e. rubber crumbs from discarded tires), the heterogeneity is increased. Based on this, it is of importance to determine to what degree the accepted protocols, valid for traditional materials, are applicable to newly developed construction materials with particular interest to rubberized concrete. Several tests, including parameters missing from the standardized measurement techniques, such as the increasing rate of the frequency during the sweep for finding the resonant frequency of the specimen, were conducted on two types of concrete: traditional and rubberized concrete. The assessment of the dynamic properties was done by means of the forced vibration method and the impact method. The obtained results indicate the fact that current procedures should be applied with care when considering aggregate replacement in traditional concrete by other recycled materials.

scholarly journals Benefits of implementing IT tools and procedures for the estimation and measurement uncertainty in testing laboratories

2020 ◽  
Vol 2 (7) ◽  
pp. 317-323
Author(s):  
Maria Cristina Dijmarescu
Keyword(s):  
Measurement Uncertainty ◽  
Rapid Expansion ◽  
Market Demand ◽  
Destructive Testing ◽  
Continuous Increase ◽  
Testing Laboratories ◽  
Quality Of Products ◽  
The Impact ◽  
Non Destructive

Destructive and non-destructive testing of materials present a rapid expansion given by the increase in market demand caused by the desire to obtain an increasingly better quality of products. The continuous increase in quality demands leads directly to the need to implement and modernize the techniques, methods, and equipment used for quality control. Consequently, the need for product testing services has a rapid growth. This paper presents the strength and weaknesses of implementing IT tools for the estimation of the measurement uncertainty in testing laboratories and the impact of these tools on the economic part

scholarly journals Study on joint detection of fabricated concrete shear wall based on percussion method

2019 ◽  
Vol 277 ◽  
pp. 03019
Author(s):  
Bo Song ◽  
Jian Li ◽  
Man sheng Wang
Keyword(s):  
Great Influence ◽  
Peak Frequency ◽  
Joint Detection ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Knock Detection ◽  
The Time Domain ◽  
The Impact ◽  
Non Destructive ◽  
Peak Value

The knock detection method is one of the non-destructive testing methods for assembly prefabricated components. The knocker is used to knock on the concrete prefabricated components to be tested. The internal conditions of the tested components can be judged by analyzing the time-domain and frequency-domain diagrams of the knocker. In this paper, the impact of the change of the knock point on the detection is studied by using the knock detection experiment. It is found that the location of the knock point has a great influence on the detection. With the change of the position of the knock point, the peak frequency in the spectrum obtained by the detection changes correspondingly. According to the frequency information corresponding to the peak value in the spectrum, the depth of the void to the knock surface can be calculated.

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.

Influence of the Supplementary Cementitious Materials on the Dynamic Properties of Concrete

2014 ◽  
Vol 660 ◽  
pp. 162-167
Author(s):  
Elbachir Elbahi ◽  
Sidi Mohammed El Amine Boukli Hacene
Keyword(s):  
Dynamic Modulus ◽  
Dynamic Properties ◽  
Construction Materials ◽  
Cementitious Materials ◽  
Supplementary Cementitious Materials ◽  
Natural Pozzolan ◽  
Frequency Method ◽  
Concrete Mixtures ◽  
And Control ◽  
Non Destructive

The resonance frequency method is one of many non-destructive tests which allow us to evaluate construction materials. It was used to determine the dynamic properties of concrete, required in structures design and control, also considered as the key elements for materials dynamic. In this study, we chose a non-destructive approach to quantify-in laboratory-, the influence of adding “crushed limestone” and “natural pozzolan” on local concrete’s dynamic characteristics. However, several concrete mixtures have been prepared with limestone aggregates. The experimental used plan, allowed us to determine the dynamic modulus of elasticity, the dynamic modulus of rigidity of different formulated concretes.

scholarly journals Risk Based Inspection of Jackets Submitted to Through-Wall Cracks

2003 ◽  
Author(s):  
Franck Schoefs ◽  
Mustapha Rguig
Keyword(s):  
Decision Aid ◽  
Structural Integrity ◽  
Offshore Structures ◽  
Probability Of Detection ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Probability Of False Alarm ◽  
The Impact ◽  
Non Destructive ◽  
Rational Process

The actual challenge for the requalification of existing offshore structures through a rational process of reassessment leads to state the importance of Risk Based Inspection methodology. This paper points out the inspection results modelling and their contribution to decision aid tools. The study of the impact of through cracks on structural integrity of jacket platforms is still a challenge. The detection of large cracks is first addressed. In order to minimize inspections and maintenance costs, all the available data from inspection results, such as probability of detection and probability of false alarm, must be addressed, as well as the probability of crack presence. This can be achieved by the use of the decision theory. These capabilities of Non Destructive Testing give a first input for the risk study. A cost function is suggested to introduce this modelling into a risk analysis and is devoted to help rank the NDT tools. The case of large through-wall cracks is specifically addressed.

scholarly journals Robotic Model for Unmanned Crack and Corrosion Inspection

2019 ◽  
Vol 9 (1) ◽  
pp. 862-867 ◽  
Keyword(s):  
Structural Integrity ◽  
Oil And Gas ◽  
Processing Technique ◽  
High Rate ◽  
Image Processing Technique ◽  
Destructive Testing ◽  
Periodic Inspection ◽  
The Cost ◽  
The Impact ◽  
Non Destructive

After prolonged usage of materials, the formation of cracks and corrosion initiates due to stress, loading condition, the environment of operation, etc. and this affects the structural integrity of structures. Periodic inspection of structures is usually planned, especially in industries where the impact of failure could be devastating, such as oil and gas pipelines, storage tanks, vessels, and airplanes, etc. which are just a few amongst others. This inspection is often aimed at detecting cracks and corrosion of internal and external components using several forms of non-destructive testing mechanism usually performed by a specialist at a high rate. To reduce the cost of inspection as well as downtime due to inspections and maintenance, deployments of mobile robots with fault tracking and identification purpose are steadily increasing. This paper, therefore, details the implementation of an image processing technique using MATLAB to identify defects of structural elements.

scholarly journals CFRP Non-Destructive Testing Using IR Thermography Methods

Proceedings ◽  
2019 ◽  
Vol 27 (1) ◽  
pp. 30
Author(s):  
Swiderski
Keyword(s):  
Construction Materials ◽  
Non Destructive Testing ◽  
Ir Thermography ◽  
Destructive Testing ◽  
Active Infrared Thermography ◽  
Multilayer Composites ◽  
Military Applications ◽  
Different Types ◽  
The Many ◽  
Non Destructive

Multilayer composites reinforced fibres are often used in military applications as construction materials for lightweight ballistic covers that protect against fragments and projectiles. The basic fibre used in these applications is aramid fibre, but research is also conducted using carbon fibres. One of the many methods used in non-destructive testing of composites is active infrared thermography, in which different types of sources can be used to thermally stimulate the material being tested. This paper compares the results obtained with various methods of thermal stimulation in the study of samples made with CFRP with deliberately introduced defects and destructive tests.

Stress State Determination in Boat Welding Using Magnetic Barkhausen Noise

2014 ◽  
Vol 605 ◽  
pp. 633-636
Author(s):  
Kaliopi Hliadi
Keyword(s):  
Stress State ◽  
Ferromagnetic Materials ◽  
Physical Principle ◽  
Barkhausen Noise ◽  
Magnetic Barkhausen Noise ◽  
Destructive Testing ◽  
Magnetic Techniques ◽  
Stress Dependent ◽  
The Impact ◽  
Non Destructive

The impact of stress on changes in magnetization is one of the most complex issues of magnetism. Magnetic techniques are the most important non-destructive testing technologies to characterize the mechanical features of ferromagnetic materials based on the physical principle of magnetic-stress coupling. Magnetic Barkhausen Noise measurement was used in order to estimate stress state in boat welding. The results have shown that magnetic properties of ferromagnetic materials are stress-dependent. A qualitative correlation was found between places with residual stress and areas with increased values of the gradients of the magnetic Barkhausen noise components. Further research is now in progress in order to develop the quantitative relationships.

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