Experimental study of attenuation coefficient of ultrasonic waves in concrete and plaster

Abstract

This study has been dedicated to the determination and comparison of ultrasound attenuation coefficient in two kinds of frequently used masonry, namely concrete and plaster. The results of this investigation can be mainly applied for optimum acoustical designing of buildings which are exposed to high-power ultrasonic waves. Another expected benefit of this investigation is determining the possibility of using ultrasonic wave emissions for finding people who are buried under ruined building materials due to an earthquake. In this paper, the attenuation coefficient of 19.7 kHz ultrasonic waves are presented for nine different concrete specimens and three different plaster specimens. For this purpose, the amplitude of vibration speed of the back and frontal surfaces of the specimens were measured by a non-contact laser sensor while the front surface was actuated by a 200-W ultrasonic transducer. The variables of concrete were weight proportion between water and cement, weight proportion between course aggregate and fine aggregate, weight proportion of cement replaced with micro-silica, and the type of cement. The variable for plaster pieces was the weight proportion of water and plaster.

Simulation study on ultrasonic tomography for grouted reinforced concrete by finite element

“…A rectangular concrete background region (1616 mm× 500 mm) contains three circular targets (109 mm in diameter unless specially noted, to simulate the tendon ducts), and twenty 10 mm-diameter steel tenders for reinforcements are placed inside the background along the top and bottom boundaries, respectively. The acoustic properties used for cases 1−4 are listed in Table 1, and the values for acoustic velocity and attenuation coefficient are chosen to be close to real sceneries [10].…”

“…Thus, this method can only give a rough estimation of the locations of voids or cracks. Ray based methods, such as refractive-index tomography [9] and attenuation tomography [10], assume that ultrasound travels in a line, which is only valid if the acoustic property distribution is generally homogenous in the reconstruction domain, and these algorithms are seldom studied nowadays. Ray tracing based USCT is the mostly used means in current study of concrete imaging, such as the inspection of bridge foundation piles [11], dam arches [12], and other civil engineering applications.…”

Vibration-based pervasive computing and intelligent sensing

“…It is intuitive that the vibration wave will lose energy during the propagation from one position to another due to the propagation medium's damping. The relationship between the attenuation of amplitude and propagation distance can be modeled as (Abdullah and Sichani 2009): Fig. 1 Illustration of single-degree-of-freedom model (Chen et al 2019) where A 0 is the initial amplitude of vibration source, d is the propagation distance and is the damping coefficient which can be further represented as (Kim and Lee 2000):…”