near-fault ground motions with long-period pulses can place severe demands on structures near an active fault. these pulse-type ground motions can be represented by pulse sequences with simple shapes. half-sinusoidal pulse sequences are used to approximate recorded ground motions and dynamic responses of sdof system under the excitation of these pulse sequences are studied. four cases are consi...

In order to get, at the ultrasonic receiver input, a clear echo pulse, it is very important to apply on the transducer a short high amplitude pulse (hundreds of volts). The pulse frequency is low enough to allow the reception and processing of the informations received from the analysed material between two adjacent pulses, but high enough to ensure an integral control of the material. The piez...

Compressive strength and elasticity modulus are the main mechanical properties of concrete. The non-destructive ultrasound pulse test can be used to determine these without compromising structure’s integrity. This study seeks assess whether a correlation exists (1) between Reinforcement Index (RI) properties, (2) RI dynamic (3) among polypropylene fiber-reinforced was modified through fiber vol...

The mechanical properties of polymer impregnated concrete containing polypropylene fiber were statistically and experimentally examined in this study. Taguchi L9 (33) was used variables for experiments selected as the ratio (0%, 1% 2%), cement dosage (300, 350 400 kg/m3) curing time (7, 14 28 days). After specimens cured at specified times, they dried 105 ±5 °C. Then, monomer to 24 hours under ...

Ultrasonic testing is a versatile and important nondestructive testing method. In many industrial applications, ultrasonic testing is carried out at relatively high temperatures. Since the ultrasonic w...

With advancing age, arterial stiffness and wave reflections increase and elevate systolic and pulse pressures. An elevated central pulse pressure is generally ascribed to increased wave reflection and portends an unfavorable prognosis. Using arterial tonometry, we evaluated central (carotid-femoral) and peripheral (carotid-brachial) pulse wave velocity, amplitudes of forward and reflected press...

Burnt bricks lined with mortar were among the materials used in the construction of historical load-bearing structures. The need to know the strength characteristics of masonry material arises during repairs of historical structures and their subsequent static securing. These can be investigated either by sampling a masonry specimen, or the employment of non-destructive testing methods. With de...

Ultrasonic is one of the most common uses of a non-destructive evaluation method for crack detection and characterization. The effectiveness of the acoustic-ultrasound Structural Health Monitoring (SHM) technique for the determination of the depth of the surface crack was presented. A method for ultrasonic sizing of surface cracks combined with the time domain and frequency spectrum was adopted...

UPV as non-destructive technique can effectively contribute to the low invasive in situ analysis and diagnosis of masonry elements related to the conservation, rehabilitation and strengthening of the built heritage. The use of non-destructive and non-invasive techniques brings all the times many advantages in diagnostic activities on pre-existing buildings in terms of sustainability; moreover, ...