scholarly journals Influence of Embedded Reinforcement in a High Strength Concrete on Ultrasonic Pulse Velocity and Core Test

2017 ◽  
Vol 14 (1) ◽  
pp. 29-34
Author(s):  
Hussam K. Risan ◽  
Omar Shamal Farhan ◽  
Abdulkalik J. Abdulridha
Keyword(s):  
High Strength Concrete ◽  
High Strength ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Strength Concrete

Estimation of Compressive Strength of Recycled Aggregate High Strength Concrete Using Ultrasonic Pulse Velocity

2014 ◽  
Vol 605 ◽  
pp. 147-150
Author(s):  
Seong Uk Hong ◽  
Seung Hun Kim ◽  
Yong Taeg Lee
Keyword(s):  
Compressive Strength ◽  
High Strength Concrete ◽  
Coarse Aggregate ◽  
High Strength ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Recycled Aggregate ◽  
Strength Concrete ◽  
Recycled Coarse Aggregate

This study used the ultrasonic pulse velocity method, one of the non-destructive test methods that does not damage the building for maintenance of to-be-constructed concrete structures using recycled aggregates in order to estimate the compressive strength of high strength concrete structure using recycled coarse aggregate and provide elementary resources for technological establishment of ultrasonic pulse velocity method. 200 test pieces of high strength concrete 40, 50MPa using recycled coarse aggregate were manufactured by replacement rates (0, 30, 50, 100%) and age (1, 7, 28, 180days), and air curing was executed to measure compressive strength and wave velocity. As the result of compressive strength measurement, the one with age of 180day and design strength of 40MPa was 43.69MPa, recycled coarse aggregate replacement rate of 30% 50% 100% were 42.82, 41.22, 37.35MPa, and 50MPa was 52.50MPa, recycled coarse aggregate replacement rate of 30% 50% 100% were 49.02, 46.66, 45.30MPa, and while it could be seen that the test piece substituted with recycled aggregate was found to have lower strength than the test piece with natural aggregate only, but it still reached the design strength to a degree. The correlation of compressive strength and ultrasonic pulse velocity was found and regression analysis was conducted. The estimation formula for compressive strength of high strength concrete using recycled coarse aggregate was found to be Fc=0.069Vp4.05, R2=0.66

Estimation of Compressive Strength of High-Strength Concrete with Recycled Aggregate Using Ultrasonic Pulse Velocity Method

2013 ◽  
Vol 680 ◽  
pp. 226-229 ◽  
Author(s):  
Young Sang Cho ◽  
Sang Ki Baek ◽  
Yong Taeg Lee ◽  
Seung Hun Kim ◽  
Jun Ho Park ◽  
...  
Keyword(s):  
Compressive Strength ◽  
High Strength Concrete ◽  
Coarse Aggregate ◽  
High Strength ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Recycled Aggregate ◽  
Strength Concrete ◽  
Recycled Coarse Aggregate

Recently, many structures which were built about 30 years ago are watched by reconstruction. Demolished concrete is occurred in the process and these quantity increase about 10% more than the preceding year. Although the government have promoted to use recycled coarse aggregate, many registered architects have not use it, because natural aggregate is still cheaper than recycled coarse aggregate's price and they have question about quality of recycled coarse aggregate. In addition, there are no grounds to rely upon compressive strength and ultrasonic pulse velocity method of recycled coarse aggregate when it is used to high strength concrete. In this paper, bases will be adduced to verify applicative possibility of estimation of compressive strength of high-strength concrete with recycled aggregate using ultrasonic pulse velocity method. For this, compressive strength and ultrasonic pulse velocity method tests of 240 high strength concrete specimens with recycled coarse aggregate were performed, and the high strength concrete specimens were tested within the limits such as compressive strength and ultrasonic pulse velocity

scholarly journals Ultrasonic Pulse Velocity and Morphology of High Strength Concrete with PVC Waste Aggregate

2020 ◽  
Vol 8 (5) ◽  
pp. 3783-3788 ◽  
Keyword(s):  
Silica Fume ◽  
High Strength Concrete ◽  
High Strength ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
High Ratio ◽  
Hardened Cement ◽  
Strength Concrete ◽  
Residual Properties

In this paper, morphology and ultrasonic pulse velocity (UPV) of high strength concrete with a relatively high ratio of condensed silica fume and PVC waste aggregate as sand replacement have been examined. The plastic aggregate was obtained from shredding PVC waste sheets used for secondary roofing and covering walls. Variables tested were PVC plastic grading and ratio of sand replacement with such plastic, in addition to curing time of concrete. Results of scanning electron microscopy showed that there is a good bond between PVC aggregate particles and hardened cement paste. There was a relatively small reduction of UPV value of concrete, increased with increasing PVC aggregate content, reached 14.3% at 40% PVC content. The UPV lost is slightly increased with increasing concrete age from 7 days to 56 days. Results also showed that the effect of PVC aggregate grading on the residual UPV is not important. Based on the measured residual properties of high strength with silica fume and PVC granules, there is a high degree of silica fume hydration and the existence of PVC particles has no effect on such hydration.

scholarly journals Assessment of Strength Development at Hardened Stage on High-Strength Concrete Using NDT

2020 ◽  
Vol 10 (18) ◽  
pp. 6261
Author(s):  
Taegyu Lee ◽  
Jaehyun Lee ◽  
Hyeonggil Choi
Keyword(s):  
Compressive Strength ◽  
High Strength Concrete ◽  
Concrete Strength ◽  
High Strength ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Temperature History ◽  
Strength Development ◽  
Strength Concrete

This study proposes model formulae for predicting the strength of concrete by analyzing the relationships between the results of nondestructive testing (NDT) methods and the compressive strength of concrete specimens at the hardened stage. Further, NDT of concrete molds and mock-up specimens was conducted using NDT methods (rebound hammer, ultrasonic pulse velocity). The water/cement (W/C) ratios were set to 0.48, 0.41, and 0.33 to achieve concrete strengths within the compressive strength range of 24–60 MPa. The evaluation parameters included the fresh concrete properties, compressive strength (mold and core), temperature history, maturity, rebound value, and ultrasonic pulse velocity. Evaluation results indicated that the reliability of existing models, based on the rebound and ultrasonic pulse velocity, is significantly low on high-strength concrete of 40 MPa or higher, and cannot satisfy the ±20% error range. Consequently, this study proposes a regression equation of the concrete strength based on the experimental rebound and ultrasonic pulse velocity values in a 24–60 MPa range, which offers satisfactory reliability.

Estimation of Compressive Strength of Concrete Member Using Ultrasonic Pulse Velocity Method

2014 ◽  
Vol 605 ◽  
pp. 143-146
Author(s):  
Yong Taeg Lee ◽  
Seong Uk Hong ◽  
Seung Hun Kim ◽  
J.H. Park
Keyword(s):  
Compressive Strength ◽  
Wave Velocity ◽  
High Strength ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Concrete Member ◽  
Strength Concrete ◽  
Estimation Formula ◽  
Normal Strength

This study uses the ultrasonic pulse velocity method, one of the non-destructive testing methods that do not damage the structure, to analyze the correlation of wave velocity and compressive strength of normal strength and high strength concrete to propose an estimation formula. And a concrete member is produced to estimate the compressive strength, and provide elementary data for establishing a site-applicable standard for strength estimation formula. In order to analyze the correlation of concrete compressive strength and wave velocity, total of 144 specimens were produced per age, and six concrete members were produced for wave velocity measurement. In this study, the Ultrasonic Pulse Velocity method was used to propose a compressive strength estimation formula of normal strength and high strength concrete, which was applied to concrete members for verification, and the following conclusion was obtained. The correlation between wave velocity and compressive strength was found to be Fc=0.0952VP3.5, R2=0.82 for normal strength concrete, and Fc=0.0028VP6.1, R2=0.83 for high strength concrete. Result of comparing the estimated strength of the concrete member of the relative error rate was standard strength 18.7% on average, the high-strength 8.7%

scholarly journals Strength Properties of High-Strength Concrete Containing Coal Bottom Ash as a Replacement of Aggregates

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
In-Hwan Yang ◽  
Jihun Park ◽  
Nhien Dinh Le ◽  
Sanghwa Jung
Keyword(s):  
Compressive Strength ◽  
High Strength Concrete ◽  
Bottom Ash ◽  
High Strength ◽  
Ultrasonic Pulse Velocity ◽  
Strength Properties ◽  
Pulse Velocity ◽  
Coal Bottom Ash ◽  
Strength Concrete ◽  
Fine Aggregates

Most previous studies on the strength properties of coal bottom ash (CBA) concrete have focused on concrete with a normal compressive strength, and thus, studies on the strength properties of high-strength concrete (HSC) containing CBA are limited. Therefore, the effects of replacing fine aggregates with CBA and variations in the curing age on the strength properties of HSC with a compressive strength of greater than 60 MPa were investigated in this study. The different CBA contents included 25, 50, 75, and 100%, and the different curing ages were 28 and 56 days. The mechanical properties of the HSC with CBA incorporated as fine aggregates were examined. The experimental results revealed that CBA could be partially or totally substituted for fine aggregates during HSC production. The test results also showed that the compressive, splitting tensile, and flexural strengths of the HSC containing CBA fine aggregates slightly decreased as the CBA content increased. Moreover, useful relationships between the compressive strength, splitting tensile strength, and flexural strength were suggested, and the predictions reasonably agreed with the measurements. Compared to those of the control specimen, the pulse velocities of the HSC specimens at various CBA contents decreased by less than 3%. In addition, equations for predicting the strength values of CBA concrete by using the ultrasonic pulse velocity were suggested.

scholarly journals High Strength Nano Silica Based Concrete

2020 ◽  
Vol 9 (7) ◽  
pp. 1150-1155
Keyword(s):  
Electron Microscope ◽  
High Strength ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Hardened Concrete ◽  
Nano Silica ◽  
Nano Structure ◽  
Transmission Electron

There is a substantial curiosity in academia, the investment community and among manufacturers about the exhilarating opportunities offered by nano materials. Although a lot of applications for nanotechnology remain hypothetical, construction is one area where numerous ‘here and now’ applications have already emerged. While existing use is restricted, the market is likely to approach more than 500 million dollars within ten years. Concrete is most likely exceptional in the construction field, that it is the distinct material exclusive to business and hence, is the recipient of a reasonable quantity of research and development capital from the construction industry. SiO2 (Silica) usually is an integral part of concrete in the normal mix. On the other hand, one of the innovations made by the study of concrete at nano scale level is that particle stuffing in concrete can be enhanced by means of adding nano silica (NS), which results in the densification of the micro and nano structure of cementitious composite resulting in enhanced mechanical properties. In this research paper, the result of a thorough investigational analysis on the utilization of NS in addition to cement so that the strength and quality of concrete can improve has been achieved. The effect of various proportions of NS in concrete has been premeditated to evaluate the properties of NS based hardened concrete according to the standard concrete. The obtained outcomes after testing indicate that the addition of NS together with concrete has improved the mechanical behavior of concrete. The NS blended high strength concrete (HSC) shows a better compressive strength (CS) of 66.00 N/mm2 (MPa) after standard twenty eight days, which is an exceptional development over standard concrete. Each and every mixture containing NS in various proportions gave enhanced outcomes in comparison with the standard predictable concrete. RH (Rebound Hammer), UPV (Ultrasonic Pulse Velocity), SEM (Scanning Electron Microscope) and TEM (Transmission Electron Microscope) examinations further authenticate the above results.

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