scholarly journals Study on robustness of rebound hammer and ultrasonic pulse velocity measurement in several concrete damage levels

2021 ◽  
Vol 708 (1) ◽  
pp. 012069
Author(s):  
N N Kencanawati ◽  
Akmaluddin ◽  
R Marlitasari ◽  
G Paedullah
Keyword(s):  
Velocity Measurement ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Rebound Hammer ◽  
Concrete Damage

scholarly journals Structural Audit of Sadhu Vaswani Pul using Institutionally Developed Displacement Sensors.

2020 ◽  
Vol 9 (9) ◽  
pp. 387-394
Keyword(s):  
Real Time ◽  
Bridge Deck ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Rebound Hammer ◽  
Reliable Test ◽  
Displacement Sensors ◽  
Rolling Load ◽  
Critical Sections

The main aim of this study is to conduct the structural audit of the Sadhu Vaswani Pul which is a Rail Over Bridge, situated in Koregaon Park, Pune and to establish the displacement sensors developed in the institution as a reliable test for structural auditing of the bridge decks. Traditional methods of auditing like the Rebound Hammer test and the Ultrasonic pulse velocity tests have been considered in this study. Very few methods are available for testing the deck displacement and this problem has been tackled here. The novelty of this research is that the institutionally developed displacement sensors are used for determining the deck displacement of the selected bridge. These sensors have not been used before and no on-site techniques are available to obtain the deck deflections under real-time loading. The displacement test on the decks was conducted. The critical decks which were determined during the Visual Inspections were tested by the displacement sensors. A two-axle truck of 18.5 tonnes was passed over the bridge deck and the displacement readings were recorded at the same time. The displacement reading thus obtained indicated the deflection of the deck under a uniform rolling load. The displacements obtained were then validated by the standards given in AASTHO-LFRD. After conducting the above tests, the overall condition of the bridge was determined and the critical sections which should be repaired were mentioned.

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.

scholarly journals Combined Use of Ultrasonic Pulse Velocity and Rebound Hammer for Structural Health Monitoring of Reinforced Concrete Structures

2019 ◽  
Author(s):  
Ahmed Lasisi ◽  
Obanishola Sadiq ◽  
Ibrahim Balogun
Keyword(s):  
Concrete Strength ◽  
Linear Regression Analysis ◽  
Concrete Structures ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Second Phase ◽  
Rebound Hammer ◽  
Combined Use ◽  
Non Destructive

This work investigates the use of Non-destructive tests as a tool for monitoring the structural performance of concrete structures. The investigation encompassed four phases; the first of which involved the use of destructive and non-destructive mechanisms to assess concrete strength on cube specimens. The second phase research focused on site assessment for a twin engineering theatre located at the Faculty of Engineering, University of Lagos using rebound hammer and ultrasonic pulse velocity tester. The third phase was the use of linear regression analysis model with MATLAB to establish a relationship between calibrated strength as well as ultrasonic pulse velocities with their corresponding compressive strength values on cubes and values obtained from existing structures. Results show that the root-mean squared-R2 values for rebound hammer ranged between 0.275 and 0.742 while ultrasonic pulse velocity R2 values were in the range of 0.649 and 0.952 for air curing and water curing systems respectively. It initially appeared that the Ultrasonic pulse velocity was more suitable for predicting concrete strength than rebound hammer but further investigations showed that the latter was adequate for early age concrete while the former was more suited for aging concrete. Hence, a combined use is recommended in this work.

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 “Structural Audit of an Old Building” (A Case Study)

2021 ◽  
Vol 1197 (1) ◽  
pp. 012054
Author(s):  
Ragini Kondalkar ◽  
Nikhil H. Pitale ◽  
K.R. Dabhekar ◽  
D.P. Mase
Keyword(s):  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Structural Element ◽  
Half Cell ◽  
Rebound Hammer ◽  
Cell Test ◽  
Non Destructive

Abstract In India there are infinite old structures that are at the verge of damages. There are many buildings which have reduced their strength due to time passes, due to deterioration of concrete from structural element, due to development of cracks. The structure is a combination of load carrying members, damages in members cause failure of structure and it is harmful for living beings. To prevent old structure from failure the technique is adopted know as Non-Destructive Testing (NDT). With the help of non-destructive testing auditing of an old structure is get easier. NDT examine the total health of an infrastructure in order to check strength and stability of building. NDT is a bunch of various testing consist of Ultrasonic pulse velocity test (UPV), Rebound hammer test (RHT), Half-cell test, etc. Conducting NDT on building and analyzing testing result decide to repair building as per IS code, technique like grouting, Retrofitting, etc. to increase strength and stability of building. In this project structural has to be done on old structure which is situated at Nagpur. Audit done by NDT consist of Ultra-sonic pulse velocity test, Rebound hammer test, Half-cell test. After analyzing all test result including visual inspection it is found that structure need to repair and retrofitted to make it safe and stable for all static loadings. Column jacketing also provide to structure.

scholarly journals Structural Audit of Old Building And It's Strengthening : Review

2020 ◽  
pp. 563-566
Author(s):  
Monis Azhar Ansari ◽  
Shrikant Solanke ◽  
Aashish Soni
Keyword(s):  
Human Life ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Rebound Hammer ◽  
Destructive Test ◽  
Prone Area ◽  
Pulse Echo ◽  
Non Destructive ◽  
Pulse Echo Method

We are building the structures rapidly in the area where there is requirement of the structures. Every structure has its own service life. Every structure is designed by assuming its life of existence. Some of the structures gets more life than expected and some gets fail in achieving its life. Any technology or material has its limitation to withstand. Many of the structures of R.C.C. are located in Seismic prone area. The structures gets damaged due to earthquake and the structures which becomes old should be checked that whether it has the strength of existence or not. The structures should be audited timely for the safety of the human life as well as for the nearby structures. The structures can be checked by various methods of Non-Destructive Test (Rebound Hammer Test, Ultrasonic Pulse Velocity Method, Pulse Echo Method, Probe Penetration Test, Destructive Test. Rebound Hammer Test of Non-Destructive Test is used in this paper to check the strength of an institutional building. When examining the structure, this paper aims to expand the life of structure. Different techniques of Retrofitting is given to the structural member which is unsafe. By applying the retrofitting, the structure can be made safe.

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.

Sign in / Sign up

Export Citation Format

Share Document