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.

scholarly journals Applying Artificial Intelligence to Improve On-Site Non-Destructive Concrete Compressive Strength Tests

Crystals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1157
Author(s):  
Tu Quynh Loan Ngo ◽  
Yu-Ren Wang ◽  
Dai-Lun Chiang
Keyword(s):  
Artificial Intelligence ◽  
Compressive Strength ◽  
Prediction Models ◽  
Concrete Strength ◽  
Pulse Velocity ◽  
Statistical Regression ◽  
Concrete Compressive Strength ◽  
Major Drawback ◽  
Non Destructive

In the construction industry, non–destructive testing (NDT) methods are often used in the field to inspect the compressive strength of concrete. NDT methods do not cause damage to the existing structure and are relatively economical. Two popular NDT methods are the rebound hammer (RH) test and the ultrasonic pulse velocity (UPV) test. One major drawback of the RH test and UPV test is that the concrete compressive strength estimations are not very accurate when comparing them to the results obtained from the destructive tests. To improve concrete strength estimation, the researchers applied artificial intelligence prediction models to explore the relationships between the input values (results from the two NDT tests) and the output values (concrete strength). In-situ NDT data from a total of 98 samples were collected in collaboration with a material testing laboratory and the Professional Civil Engineer Association. In-situ NDT data were used to develop and validate the prediction models (both traditional statistical models and AI models). The analysis results showed that AI prediction models provide more accurate estimations when compared to statistical regression models. The research results show significant improvement when AI techniques (ANNs, SVM and ANFIS) are applied to estimate concrete compressive strength in RH and UPV tests.

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 Assessment of Concrete Compressive Strength by Ultrasonic Non-Destructive Test

2021 ◽  
Vol 318 ◽  
pp. 03004
Author(s):  
AbdulMuttalib I. Said ◽  
Baqer Abdul Hussein Ali
Keyword(s):  
Compressive Strength ◽  
Salt Content ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Experimental Program ◽  
Concrete Compressive Strength ◽  
Statistical Program ◽  
Non Destructive ◽  
Accurate Relation

This paper has carried out an experimental program to establish a relatively accurate relation between the ultrasonic pulse velocity (UPV) and the concrete compressive strength. The program involved testing concrete cubes of (100) mm and prisms of (100×100×300) cast with specified test variables. The samples are tested by using ultrasonic test equipment with two methods, direct ultrasonic pulse (DUPV) and surface (indirect) ultrasonic pulse (SUPV) for each sample. The obtained results were used as input data in the statistical program (SPSS) to predict the best equation representing the relation between the compressive strength and the ultrasonic pulse velocity. In this research 383 specimens were tested, and an exponential equation is proposed for this purpose. The statistical program has been used to prove which type of UPV is more suitable, the (SUPV) test or the (DUPV) test, to represent the relation between the ultrasonic pulse velocity and the concrete compressive strength. In this paper, the effect of salt content on the connection between the ultrasonic pulse velocity and the concrete compressive strength has also been studied.

scholarly journals Experimental study on the effect of concrete strength and corrosion level on bond between steel bar and concrete

2021 ◽  
Vol 72 (4) ◽  
pp. 498-509
Author(s):  
Vuong Doan Dinh Thien ◽  
Hung Nguyen Thanh ◽  
Hung Nguyen Dinh
Keyword(s):  
Compressive Strength ◽  
Bond Strength ◽  
Concrete Strength ◽  
Concrete Block ◽  
Bond Stress ◽  
Concrete Compressive Strength ◽  
Pull Out ◽  
Steel Bar ◽  
Stress Degradation ◽  
Slip Displacement

Corrosion of the steel reinforcement bars reduces the area of the steel bar and the bond stress between the steel bars and around concrete that decreases the capacity of concrete structures. In this study, the bond stress between steel bar with a diameter of 12mm and concrete was examined with the effect of different corrosion levels and different concrete grades. A steel bar was inserted in a concrete block with a size of 20×20×20cm. The compressive strength of concrete was 25.6MPa, 35.1MPa, and 44.1MPa. These specimens were soaked into solution NaCl 3.5% to accelerate the corrosion process with different corrosion levels in the length of 60mm. The pull-out test was conducted. Results showed that the bond strength of the corroded steel bar was higher than that predicted from CEB-FIP. Slip displacement and the range of slip displacement at the bond strength were reduced when the concrete compressive strength was increased. The rate of bond stress degradation occurred faster with the increment of the corrosion level when the concrete compressive strength was increased.

Estimating the Concrete Compressive Strength by Using the Concrete Ultrasonic Pulse Velocity and Moduli of Elasticity

2021 ◽  
Vol 1164 ◽  
pp. 77-86
Author(s):  
Bogdan Bolborea ◽  
Sorin Dan ◽  
Claudiu Matei ◽  
Aurelian Gruin ◽  
Cornelia Baeră ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Ultrasonic Testing ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
High Rate ◽  
Concrete Compressive Strength ◽  
Destructive Testing ◽  
Non Destructive ◽  
Moduli Of Elasticity

Developing a non-destructive method which delivers fast, accurate and non-invasive results regarding the concrete compressive strength, is an important issue, currently investigated by many researchers all over the world. Different methodologies, like using the simple non-destructive testing (NDT) or the fusion of different techniques approach, were taken into consideration in order to find the optimal, most suitable method. The purpose of this paper is to present a new approach in this direction. The methodology consists in predicting the concrete compressive strength through ultrasonic testing, for non-destructive determination of the dynamic and static moduli of elasticity. One important, basic assumption of the proposed methodology considers values provided by technical literature for concrete dynamic Poisson’s coefficient. The air-dry density was experimentally determined on concrete cores. The dynamic modulus of elasticity was also experimentally determined by using the ultrasonic pulse velocity (UPV) method on concrete cores. Further on, the static modulus of elasticity and the concrete compressive strength can be mathematically calculated, by using the previously mentioned parameters. The experimental procedures were performed on concrete specimens, namely concrete cores extracted from the raft foundation of a multistorey building; initially they were subjected to the specific NDT, namely ultrasonic testing, and the validation of the results and the proposed methodology derives from the destructive testing of the specimens. The destructive testing is generally recognized as the most trustable method. The precision of the proposed method, established with respect to the destructive testing, revealed a high level of confidence, exceeding 90% (as mean value). It was noticed that even the cores with compressive strength outside of mean range interval (minimum and maximum values) presented high rate of precision, not influencing the overall result. The high rate of accuracy makes this method a suitable research background for further investigations, in order to establish a reliable NDT methodology which could substitute the very invasive and less convenient, destructive method.

Assessment of Compressive Strength for RC Building Using the Non-Destructive Test and the SonReb Method: A Case Study

2021 ◽  
Vol 1021 ◽  
pp. 45-54
Author(s):  
Mohammed Al-Helfi ◽  
Ali Allami
Keyword(s):  
Compressive Strength ◽  
Concrete Strength ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Test Method ◽  
Technical Institute ◽  
Existing Building ◽  
Destructive Test ◽  
Non Destructive

Non-Destructive methods have greater advantage in assessing the homogeneity, compressive strength, corrosion of rebars in concrete etc. of damaged structures. The aim of the present study is to assess the existing building, which is 41 year old, in the Technical Institute of Amara affiliated with the Southern Technical University, Maysan, Iraq. The research focus on the assessment of the concrete strength and the inspection of the damages in the building. Besides the visual inspection, the ultrasonic pulse velocity and schmidt hammer were used as a non-destructive test method for testing of 30 columns and 15 beams for a building consisting of three floors. The concrete compressive strength was estimated by using SonReb method. The equations proposed by Gasparik, 1984, Di Leo & Pascale, 1994, Arioglu et al., 1996, Cristofaro et al. (EXP), 2020 and Cristofaro et al (PW), 2020 were used for assessment the compressive strength of oncrete. The non-destructive test results indicated that the average strength of the structural elements greater than the design compressive strength of the tested elements. Therefore, the building can be considered structurally is safe.

Adapting ANNs in SONREB Test to Estimate Concrete Compressive Strength

2018 ◽  
Vol 792 ◽  
pp. 166-169
Author(s):  
Yu Ren Wang ◽  
Loan T.Q. Ngo ◽  
Yi Fan Shih ◽  
Yen Ling Lu ◽  
Yi Ming Chen
Keyword(s):  
Compressive Strength ◽  
Estimation Error ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Percentage Error ◽  
Non Destructive Testing ◽  
Concrete Compressive Strength ◽  
Destructive Testing ◽  
Non Destructive

SONREB method is a non-destructive testing (NDT) method for estimating the concrete compressive strength. It is conducted by combining two popular NDT methods: ultrasonic pulse velocity (UPV) test and rebound hammer (RH) test. Several researches have been attempted to find the correlation of the different testing method data with actual compressive strength. This research proposes a new Artificial Intelligence based approach, Artificial Neural Networks (ANNs), to estimate the concrete compressive strength using the UPV and RH test data. Data from a total of 315 cylinder concrete samples are collected to develop and validate the ANFIS prediction model. The model prediction results are compared with actual compressive strength using mean absolute percentage error (MAPE). With the adaption of ANFIS, the estimation error of SONREB test can be reduced to 5.98% (measured by MAPE).

Influences of Limestone Aggregates on Concrete Strength in Pipe Piles Production

2014 ◽  
Vol 584-586 ◽  
pp. 1370-1374
Author(s):  
Yuan Hai Jiang
Keyword(s):  
Compressive Strength ◽  
Coarse Aggregate ◽  
Concrete Strength ◽  
Normal Pressure ◽  
Concrete Compressive Strength ◽  
Steam Curing ◽  
Coarse Aggregates ◽  
Siliceous Rocks ◽  
Pressure Steam ◽  
Autoclave Curing

Taking the limestone and siliceous rocks as coarse aggregates to mix concrete,through normal pressure steam curing and autoclave curing,the concrete compressive strength after demould and compressive strength after autoclave curing are tested.The results indicate that the concrete compressive strength increases obviously after normal pressure steam curing when taking the limestone and granite as coarse aggregates,and the strength increasing laws are basically in accordance.However,the concrete compressive strength is great different after autoclave curing when taking the limestone and granite as coarse aggregates,the concrete strength increases lower with limestone as coarse aggregate,but the concrete strength increases higher with siliceous rocks as coarse aggregate.

Effect of high temperature on SCC containing fly ash

2021 ◽  
Vol 12 (1) ◽  
pp. 1
Author(s):  
Mehmet Canbaz ◽  
Erman Acay
Keyword(s):  
Compressive Strength ◽  
High Temperature ◽  
Fly Ash ◽  
Concrete Strength ◽  
Experimental Studies ◽  
Strength Loss ◽  
Ultrasonic Pulse Velocity ◽  
Pulse Velocity ◽  
Unit Weight ◽  
Self Compacting Concrete

The effect of high temperature on self-compacting concrete, which contains different amounts of fly ash, has been investigated. By considering the effect of concrete age and increased temperatures, the optimum fly ash-cement ratio for the optimum concrete strength is determined using experimental studies. Self-compacting concrete specimens are produced, with fly ash/cement ratios of 0%, 20% and 40%. Specimens were cured for 28, 56 and 90 days. After curing was completed, the specimens were subjected to temperatures of 20°C, 100°C, 400°C, 700°C and 900°C for three hours. After the cooling process, tests were performed to determine the unit weight, ultrasonic pulse velocity and compressive strength of the specimens. According to the experiment results, an increase in fly ash ratio causes a decrease in the compressive strength of self-compacting concrete. However, it positively contributes to self-compaction and strength loss at high temperatures. The utilization of fly ash in concrete significantly contributes to the environment and the economy. For this reason, the addition of 20% fly ash to concrete is considered to be effective.

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