scholarly journals Evaluation of Nano-Silica Modified ECC Based on Ultrasonic Pulse Velocity and Rebound Hammer

2017 ◽  
Vol 11 (1) ◽  
pp. 638-649 ◽  
Author(s):  
Bashar S. Mohammed ◽  
Zubair Imam Syed ◽  
Veerendrakumar Khed ◽  
Muthanna Saad Qasim
Keyword(s):  
Compressive Strength ◽  
Construction Industry ◽  
Coarse Aggregate ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Cementitious Composite ◽  
Nano Silica ◽  
Rebound Hammer ◽  
Nondestructive Tests

Introdcution:Engineered cementitious composite (ECC) has gained attention among researchers due to its superior tensile properties. To improve its modulus elasticity, due to absence of coarse aggregate, nano-silica (NS) has been added to ECC mixture.Method:To facilitate the usage of the NS-ECC in the construction industry, using nondestructive tests such as rebound hammer (RH) and ultrasonic pulse velocity (UPV) to predict the compressive strength of NS-ECC is worthwhile. Twenty mixtures with two variables which are four PVA% (0.5, 1, 1.5 and 2) and five NS% (0, 1, 2, 3 and 4) have been proportioned, cast, cured and tested using RH, UPV and then crushed to determine the compressive strength at age of 28 days.Results and Conclusion:Response surface methodology (RSM) has been performed to develop models for predicting the compressive strength of NS-ECC utilizing results from RH and UPV. It has been established that the newly developed models are significant with values of “Prob > F” less than 0.05 and also have variance less than 0.2. Therefore, these models can be used to predict the compressive strength of NS-ECC using rebound hammer or/and ultra-pulse velocity.

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

scholarly journals Performance Evaluation of Concrete using Marble Mining Waste

2016 ◽  
Vol 11 (2) ◽  
pp. 53-66 ◽  
Author(s):  
Sudarshan Dattatraya Kore ◽  
A. K. Vyas
Keyword(s):  
Compressive Strength ◽  
Coarse Aggregate ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Mining Waste ◽  
Partial Replacement ◽  
Infrastructure Development ◽  
The Impact ◽  
Marble Waste

Abstract A huge amount waste (approximately 60%) is generated during mining and processing in marble industries. Such waste can be best utilized in infrastructure development works. Coarse aggregate 75% by weight was replaced by aggregate obtained from marble mining waste. The impact of marble waste as a partial replacement for conventional coarse aggregate on the properties of concrete mixes such as workability, compressive strength, permeability, abrasion, etc. was evaluated. The test results revealed that the compressive strength was comparable to that of control concrete. Other properties such as workability of concrete increased, water absorption reduced by 17%, and resistance to abrasion was marginally increased by 2% as compared to that of control concrete. Ultrasonic pulse velocity and FTIR results show improvement in quality of concrete with crushed marble waste. From the TGA analysis it was confirmed that, aggregate produced from marble waste shows better performance under elevated temperature than that of conventional aggregates.

scholarly journals Empirical Investigation on Compressive Strength of Geopolymer and Conventional Concretes by Nondestructive Method

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
B. Ravali ◽  
K. Bala Gopi Krishna ◽  
D. Ravi Kanth ◽  
K. J. Brahma Chari ◽  
S. Venkatesa Prabhu ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Nondestructive Method ◽  
Geopolymer Concrete ◽  
River Sand ◽  
Rebound Hammer ◽  
Compressive Strength Of Concrete

Need of construction is increasing due to increase in population growth rate. The geopolymer concrete is eco-friendly than ordinary concrete. Current experimental investigation was conducted on ordinary and geopolymer concrete using nondestructive testing (NDT) tests like ultrasonic pulse velocity (UPV) test and rebound hammer (RH) test. Cube specimens of dimensions 150 mm × 150 mm × 150 mm are used to conduct these tests at 7, 14, and 28 days. Proportions considered for concrete are cement-fly ash-river sand (100-0-100% and 60-40-100%), cement-fly ash-robo sand (100-0-100% and 60-40-100%) whereas geopolymer concrete fly ash-metakaolin is taken in proportions of 100-0%, 60-40%, and 50-50%. Alkaline activators (sodium hydroxide and sodium silicate with molarity 12M) were used in preparing geopolymer concrete. The major objective of the current study is to obtain relation between compressive strength of concrete and UPV values.

Sodium Exposure Tests on Limestone Concrete Used as Sacrificial Protection Layer in FBR

2006 ◽  
Author(s):  
F. C. Parida ◽  
S. K. Das ◽  
A. K. Sharma ◽  
P. M. Rao ◽  
S. S. Ramesh ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Concrete Block ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Hydrogen Gas ◽  
Test Duration ◽  
Structural Concrete ◽  
Rebound Hammer ◽  
Core Samples

Hot sodium coming in contact with structural concrete in case of sodium leak in FBR system cause damage as a result of thermo-chemical attack by burning sodium. In addition, release of free and bound water from concrete leads to generation of hydrogen gas, which is explosive in nature. Hence limestone concrete, as sacrificial layer on the structural concrete in FBR, needs to be qualified. Four concrete blocks of dimension 600mm × 600mm × 300mm with 300mm × 300mm × 150mm cavity were cast and subjected to controlled sodium exposure tests. They have composition of ordinary portland cement, water, fine and coarse aggregate of limestone in the ratio of 1 : 0.58 : 2.547 : 3.817. These blocks were subjected to preliminary inspection by ultrasonic pulse velocity technique and rebound hammer tests. Each block was exposed for 30 minutes to about 12 kg of liquid sodium (∼ 120 mm liquid column) at 550° C in open air, after which sodium was sucked back from the cavity of the concrete block into a sodium tank. On-line temperature monitoring was carried out at strategic locations of sodium pool and concrete block. After removing sodium from the cavity and cleaning the surfaces, rebound hammer testing was carried out on each concrete block at the same locations where data were taken earlier at pre-exposed stage. The statistical analysis of rebound hammer data revealed that one of the concrete block alone has undergone damage to the extent of 16%. The loss of mass occurred for all the four blocks varied from 0.6 to 2.4% due to release of water during the test duration. Chemical analysis of sodium in concrete samples collected from cavity floor of each block helped in generation of depth profiles of sodium monoxide concentration for each block. From this it is concluded that a bulk penetration of sodium up to 30 mm depth has taken place. However it was also observed that at few local spots, sodium penetrated into concrete up to 50 mm. Cylindrical core samples of 50 mm × 150 mm long were obtained from the exposed cavity and tested for compressive strength and longitudinal ultrasonic pulse velocity (UPV). These are compared with core samples obtained from concrete cubes used as standard reference. The average reduction in UPV and compressive strength were 7% and 29% respectively indicating marginal degradation in mechanical properties of sodium-exposed concrete.

scholarly journals Characteristic Curve and Its Use in Determining the Compressive Strength of Concrete by the Rebound Hammer Test

Materials ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 2705 ◽  
Author(s):  
Dalibor Kocáb ◽  
Petr Misák ◽  
Petr Cikrle
Keyword(s):  
Compressive Strength ◽  
Regression Model ◽  
Characteristic Curve ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Confidence Bands ◽  
Rebound Hammer ◽  
Practical Applications ◽  
General Regression

During the construction of concrete structures, it is often useful to know compressive strength at an early age. This is an amount of strength required for the safe removal of formwork, also known as stripping strength. It is certainly helpful to determine this strength non-destructively, i.e., without any invasive steps that would damage the structure. Second only to the ultrasonic pulse velocity test, the rebound hammer test is the most common NDT method currently used for this purpose. However, estimating compressive strength using general regression models can often yield inaccurate results. The experiment results show that the compressive strength of any concrete can be estimated using one’s own newly created regression model. A traditionally constructed regression model can predict the strength value with 50% reliability, or when two-sided confidence bands are used, with 95% reliability. However, civil engineers usually work with the so-called characteristic value defined as a 5% quantile. Therefore, it appears suitable to adjust conventional methods in order to achieve a regression model with 95% one-sided reliability. This paper describes a simple construction of such a characteristic curve. The results show that the characteristic curve created for the concrete in question could be a useful tool even outside of practical applications.

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 Possibilities to Recycle Plastic Waste in Cementitious Materials

2020 ◽  
Author(s):  
Marija Vaičienė ◽  
Jurgita Malaiškienė
Keyword(s):  
Compressive Strength ◽  
Coarse Aggregate ◽  
Ultrasonic Pulse Velocity ◽  
Cementitious Materials ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Sem Analysis ◽  
Plastic Waste ◽  
Recycle Plastic ◽  
Microstructural Examination

In the paper, the changes of properties of expanded clay concrete when a part of the coarse aggregate is re- placed with plastic waste are discussed upon. First of all, standard expanded clay concrete specimens were formed, and then 5%, 10%, 20% share of the fraction 4/8 of the expanded clay aggregate was replaced with plastic waste. The properties of expanded clay concrete, such as the density of the mixture, the slump, the density of the dried expanded clay concrete specimens, the ultrasonic pulse velocity, the water absorption, and the compressive strength, were estab- lished and analyzed; in addition, a microstructural examination was carried out. It was found that upon striving to use the maximum share of waste (20%), it is possible to ensure about 4% higher density of expanded clay concrete and almost 50% higher compressive strength, as compared to expanded clay concrete of the control specimens. SEM analysis showed that the same minerals, i.e. portlandite, ettringite, calcite and calcium hydro silicates were identified in specimens from all batches.

scholarly journals An approach to in-situ compressive strength of concrete

2016 ◽  
Vol 64 (4) ◽  
pp. 687-695 ◽  
Author(s):  
L. Brunarski ◽  
M. Dohojda
Keyword(s):  
Compressive Strength ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Velocity Measurements ◽  
Indirect Methods ◽  
Rebound Hammer ◽  
Compressive Strength Of Concrete ◽  
Non Destructive

Abstract The paper presents the problem of estimating in-situ compressive strength of concrete in a comprehensive way, taking into account the possibility of direct tests of cored specimens and indirect methods of non-destructive tests: rebound hammer tests and ultrasonic pulse velocity measurements. The paper approaches the discussed problem in an original, scientifically documented and exhaustive way, in particular in terms of application.

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