IOSR Journal of Engineering (IOSR-JEN) Volume 5 Issue 5 Version 3

Ultrasonic Pulse Velocity (USPV) test has gained considerable popularity all over the world. Ultrasonic pulse velocity testing of concrete is based on the pulse velocity method to provide information on the uniformity of concrete, cavities, cracks and defects. The pulse velocity in a material depends on its density and its elastic properties which in turn are related to the quality and the compressive strength of the concrete. It is therefore possible to obtain information about the properties of components by sonic investigations. The investigation reported here is to present study of calibration graphs for Non Destructive Testing (NDT) Equipment, which is ultra sonic pulse velocity test and to study the quality of the concrete in existing structures. These ultra sonic pulse velocity tests were then used to test the quality of the concrete of the various structural elements (columns and beams) of single storied newly under constructed office building. The use of this method produces results that lie close to the true values when compared with other methods. A correlation between ultra sonic pulse velocity test and strength of concrete structure is established, which can be used for strength estimation of concrete structures. The method can be extended to test existing structures by taking direct measurements on concrete elements.

2009

In civil engineering damages inside of wooden construction components (e.g. interior rot) or at inaccessible surfaces represent a special problem, as they are difficult to recognize from the outside and could even cause a sudden failure of the component. As a result of this research project, it could be proven that the ultrasonic echo technique can be used on wood. Furthermore, the different influences of the wood fibres on the sound velocity of the longitudinal and transverse waves are pointed out on the basis results of measurements. With practical measurements at hall construction elements and a bridge consisting of glulam beams with interior damage the efficiency of the ultrasonic echo technique is demonstrated. A combination of ultrasonic echo technique and radiography resulted in a substantial reduction of possible misinterpretation of damages. It is possible to detect damages from the undamaged side of the specimen by ultrasound echo. The extent of the damages can be obtained...

2014 IEEE International Ultrasonics Symposium, 2014

The application of non-destructive testing (NDT) in the analysis of trees in forest plantations permits the evaluation of the wood quality, the internal defects in development or pest attack and its characterization for application as solid wood and its products. These techniques have been constantly improved with the use of computers, electronics and agricultural control levels in order to provide tools to the specialists in integrated management. The ultrasound has been used in agriculture as NDT to determine the elasticity modulus of juvenile and mature wood of pinus and other species. This study aimed to the evaluation of new techniques for characterization of wood using parameters such as the power spectral density (PSD) and phase velocity of ultrasonic signals propagating in wood. The tests were performed using a pair of ultrasonic transducers with central frequency of 50 kHz (083-067-038, GE) which were connected to an ultrasonic pulser/receiver (5077PR, Olympus). The transmitting transducer was coupled to the samples of pinus using ultrasound gel and excited with negative pulses of short duration (5 µs) and high amplitude (-400 V) to generate longitudinal and shear waves. The ultrasound signals that propagated through the samples were received by the receiving transducer, amplified (20 to 40 dB), acquired in a digital scope (MSO4104B, Tektronix) and then transferred to a microcomputer. The tests have been done with 10 reference samples (healthy) and 10 attacked by wood wasps, with small holes in the bark. The transducers were placed on the samples in the axial, radial and inclined modes. The data were processed using the Matlab (Mathworks Inc.) to determine the power spectral density (PSD), the root mean square deviation index (cRMSDdB) and the phase velocity between the reference and attacked samples. The cRMSDdB calculated between the PSD of the reference and the attacked samples were generally higher for samples with higher degree of damage, however, in some cases, they were lower due to the presence of wood knots. The phase velocities were calculated in the frequency range 1-200 kHz and generally show higher values for the reference samples. The group velocities were also calculated and the results were in the range 1200-3000 m/s, indicating that these parameters can be used for wood characterization.

The aim of the present paper is to check the accuracy of Ultrasonic Pulse Velocity (UPV) and Rebound Hammer for assessing concrete strength that are widely used in structural field. Even though there are many methods for Non Destructive Test (NDT) but every method have it own boundaries and which mean the method cannot afford an accurate and consistence result for difference cases and to detect different defect. The NDT is applied on jetty Lembaga Kemajuan Ikan Malaysia (LKIM) at Kuantan, Pahang. The structure that has been test is the slab that was constructed in year 1989 and 2001. A general series of tests which are compression test, rebound hammer and UPV was carried out at laboratory to obtain a correlation of the NDT results with compressive strength. 24 concrete cubes of sizes 150 x 150 x 150 mm has been made and subjected to two curing condition which is water curing and air curing for 1 day, 7, 14 and 28 days. For each day stated, 3 cubes which subjected to water curing and 3 cubes subjected to air curing was tested. To get the exact result of the cube strength, compression test applied to the concrete cube. Before the compression testing applied, the cube strength checked by using UPV and rebound hammer. The data obtained from each test has been evaluated and the accurate and precise device was determined. From this research, the most accurate NDT method is Ultrasonic Pulse Velocity V

Materials and Structures, 2014

This paper summarizes the test recommendations for in situ assessment of structural timber using stress wave measurements as developed by members of the RILEM Technical Committee AST 215 ''In-situ assessment of structural timber''. In the first part, the basic principles, the equipment, and the practical application of stress-wave-based testing using the time-of-flight method are described. A detailed testing procedure provides hands-on information on the execution of in-field stress wave testing. A typical example is given to demonstrate step-by-step on how to evaluate stress wave readings and the health state of the inspected timber member. The latter part of the paper gives a short overview of the use of acoustic tomography and ultrasonic echo methods. Keywords Timber structures Á Assessment Á Stress waves Á Time-of-flight Á Tomography Á Ultrasonic echo