Guide to non-destructive concrete strength assessment: Homogeneity tests and sampling plans

2022 ◽  
pp. 104047
Author(s):  
Eman Saleh ◽  
Ahmad Tarawneh ◽  
Hazim Dwairi ◽  
Mohammad AlHamaydeh
Keyword(s):  
Concrete Strength ◽  
Homogeneity Tests ◽  
Sampling Plans ◽  
Strength Assessment ◽  
Non Destructive

scholarly journals The Use of Destructive and non Destructive Testing in Concrete Strength Assessment for a School Building

2019 ◽  
Author(s):  
Vincenzo Minutolo ◽  
Stefania Di Ronza ◽  
Caterina Eramo ◽  
Renato Zona
Keyword(s):  
Concrete Strength ◽  
Calibration Procedure ◽  
Experimental Investigations ◽  
School Building ◽  
Destructive Testing ◽  
Strength Assessment ◽  
Existing Building ◽  
Engineering Department ◽  
The University ◽  
Non Destructive

The present paper aims to increase knowlodge of the methods of resistance estimating of concrete in situ by means of non-destructive tests used to integrate the quantitative results from cylindrical specimens (core). The results of experimental investigations carried out on concrete conglomerate samples of a school building are shown. The experimental campaign then will be presented like a case study, conducted on a series of concrete beams and pillars of an existing building. The distructive tests on cores were conducted at the Civil Structures Laboratory of the Engineering Department of the University of Campania "Luigi Vanvitelli". The expression obtained through the calibration procedure of the values of non-destructive tests with those provided by the core drills allowed to estimate the average values of the compressive strength of the concrete. It is highlighted how this result was achieved with a very limited core number provided that they are extracted in selected points and that there was a proportionality link with the resistances obtained from non distructive tests.

scholarly journals Reliable non-destructive strength assessment in existing structures: myth or reality?

2019 ◽  
Vol 3 ◽  
pp. 129-134 ◽  
Author(s):  
Denys Breysse ◽  
Jean-Paul Balayssac
Keyword(s):  
Concrete Strength ◽  
Tolerance Interval ◽  
Paradigm Change ◽  
Test Results ◽  
Strength Assessment ◽  
Existing Structures ◽  
Local Strength ◽  
Definition Of ◽  
Guidelines And Recommendations ◽  
Non Destructive

The non-destructive assessment of concrete strength in existing structures is a complex issue which has been analyzed by a recently closed RILEM committee (TC ISC 249) whose Guidelines and Recommendations are to be released soon. This committee has considered the state of practice, the yet existing standards and most recent innovative research results, in order to write recommendations that would improve the reliability of strength assessment with non-destructive techniques (NDT). These recommendations are based on a paradigm change: the challenge is not that of finding the true local strength, but that of estimating its value with a controlled tolerance interval and a limited risk of being wrong. Three levels of requirements are defined which correspond to different tolerance intervals on the assessed parameters and to a different amount of resources devoted to the investigation. While most of research had been devoted until now to the identification of relevant conversion models between NDT test results and strength, we have shown that the priority had to be put on other items, including the assessment of the NDT test results repeatability, the relevant definition of core locations and the checking of the final predictive error. This paper briefly describes the main innovations included in these recommendations.

scholarly journals Pecularities of Strength Assessment of Cast-in-Situ Structures in Terms of Siberia

2020 ◽  
Vol 839 ◽  
pp. 43-50
Author(s):  
Irina G. Endzhievskaya ◽  
Iliya G. Kalugin ◽  
Sergey O. Deygraf ◽  
Maksim A. Galkin
Keyword(s):  
Concrete Strength ◽  
Experimental Studies ◽  
Physical And Mechanical Properties ◽  
Design Strength ◽  
Plant Laboratory ◽  
Strength Assessment ◽  
Integrated Research ◽  
Strength Based ◽  
Non Destructive

This article states the results of experimental studies to assess concrete strength in cast-in-situ structures based on a systematic approach, including integrated research methods at all stages of construction of reinforced concrete structures. It was established that the concrete strength of the sample-cubes made on the object simultaneously with the structure and stored under the same conditions was slightly lower than the structures and standard control samples. The decrease in the strength of concrete samples from structures is on average 13,3%. Its value is effected by several factors, one of the main was the maintenance of the structure. The most appropriate is to meet the requirements of achieving 70% of the design strength and higher percentage is required for cast-in-situ construction in terms of winter pouring concrete. At the same time, along with the assessment of the physical and mechanical properties of the structure by non-destructive methods, it is necessary to carry out tests aimed at determining the actual concrete strength based on samples made in the batching plant laboratory and solidified (cured) in permissible humidity conditions (herein after referred as PHC).

scholarly journals Prediction of concrete strength by non-destructive testing in old structures: Effect of core number on the reliability of prediction

2018 ◽  
Vol 149 ◽  
pp. 02007 ◽  
Author(s):  
Boussahoua Youcef ◽  
Kenai Said ◽  
Ali-Benyahia Khoudja
Keyword(s):  
Compressive Strength ◽  
Concrete Strength ◽  
Synthetic Data ◽  
Steel Corrosion ◽  
Pulse Velocity ◽  
Coefficient Of Determination ◽  
Calibration Model ◽  
Strength Assessment ◽  
Non Destructive

When assessing the quality of concrete on site, it is necessary to base the interpretation on reliable and representative test results. Generally, core tests are the most reliable and effective method for assessing the quality of concrete. Unfortunately, this type of testing is expensive and time consuming and only a limited number of cores can be carried out in practice. Non-destructive tests (NDT) can be used to overcome these drawbacks. The most popular and widely used NDT methods for assessing concrete strength are rebound hammer (RH) and the ultrasonic pulse velocity (UPV). The use of these methods provide unreliable predictions unless their results are correlated to destructive tests. A sufficient number of cores is needed to accurately predict the compressive strength of concrete. Recent researches have been carried out for identifying and optimizing the number of cores able to stabilize the calibration model on data from recent structures and from synthetic data. However, more case studies are needed to draw conclusions. In addition, the effect of the degradation of reinforced concrete elements on the number of cores needed for obtaining a reliable prediction needs to be investigated. In this paper, RH and UPV in conjunction with core tests are used to evaluate the concrete compressive strength in existing structures built in the 1970s and degraded mainly by steel corrosion. More than 234 elements were tested by RH and 86 elements by UPV. Also, 36 cores were drilled and tested under compression. A regression analysis is adopted to establish the correlations between NDT and strength measurements. The accuracy of the predictive assessment was evaluated using two indicators: the root mean square error (RMSE) and the coefficient of determination (r2). The results of this case study showed that seven to nine cores is the minimal number of cores that guarantees the improvement of concrete strength assessment by combined or single NDT methods.

PENGKAJIAN KEKUATAN BETON STRUKTUR JEMBATAN PASCA KEBAKARAN

2013 ◽  
Vol 12 (3) ◽  
Author(s):  
Sudarmadi Sudarmadi
Keyword(s):  
Compressive Strength ◽  
Concrete Strength ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Test Results ◽  
Concrete Compressive Strength ◽  
Strength Assessment ◽  
Concrete Testing

In this paper a case study about concrete strength assessment of bridge structure experiencing fire is discussed. Assessment methods include activities of visual inspection, concrete testing by Hammer Test, Ultrasonic Pulse Velocity Test, and Core Test. Then, test results are compared with the requirement of RSNI T-12-2004. Test results show that surface concrete at the location of fire deteriorates so that its quality is decreased into the category of Very Poor with ultrasonic pulse velocity ranges between 1,14 – 1,74 km/s. From test results also it can be known that concrete compressive strength of inner part of bridge pier ranges about 267 – 274 kg/cm2 and concrete compressive strength of beam and plate experiencing fire directly is about 173 kg/cm2 and 159 kg/cm2. It can be concluded that surface concrete strength at the location of fire does not meet the requirement of RSNI T-12-2004. So, repair on surface concrete of pier, beam, and plate at the location of fire is required.

scholarly journals Evaluation of Self-Compacting Concrete Strength with Non-Destructive Tests for Concrete Structures

2019 ◽  
Vol 9 (23) ◽  
pp. 5109 ◽  
Author(s):  
Miguel C. S. Nepomuceno ◽  
Luís F. A. Bernardo
Keyword(s):  
Compressive Strength ◽  
Concrete Strength ◽  
Surface Hardness ◽  
Pulse Velocity ◽  
Concrete Compressive Strength ◽  
Self Compacting Concrete ◽  
Coarse Aggregates ◽  
Pull Out ◽  
Concrete Maturity ◽  
Non Destructive

Self-compacting concrete (SCC) shows to have some specificities when compared to normal vibrated concrete (NVC), namely higher cement paste dosage and smaller volume of coarse aggregates. In addition, the maximum size of coarse aggregates is also reduced in SCC to prevent blocking effect. Such specificities are likely to affect the results of non-destructive tests when compared to those obtained in NVC with similar compressive strength and materials. This study evaluates the applicability of some non-destructive tests to estimate the compressive strength of SCC. Selected tests included the ultrasonic pulse velocity test (PUNDIT), the surface hardness test (Schmidt rebound hammer type N), the pull-out test (Lok-test), and the concrete maturity test (COMA-meter). Seven sets of SCC specimens were produced in the laboratory from a single mixture and subjected to standard curing. The tests were applied at different ages, namely: 1, 2, 3, 7, 14, 28, and 94 days. The concrete compressive strength ranged from 45 MPa (at 24 h) to 97 MPa (at 94 days). Correlations were established between the non-destructive test results and the concrete compressive strength. A test variability analysis was performed and the 95% confidence limits for the obtained correlations were computed. The obtained results for SCC showed good correlations between the concrete compressive strength and the non-destructive tests results, although some differences exist when compared to the correlations obtained for NVC.

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