Non-destructive ultrasonic tomography for concrete pavement evaluation: signal processing and image analysis of crucial parameters

Abstract

ResumoIn recent years, due to the destructive and unproductive character of pavement specimen extraction, pavement maintenance technology intensified the use of non-destructive techniques for pavement evaluation which resulted in the development of several devices and evaluation methods. This paper describes the use of technology based on low frequency ultrasonic tomography for evaluation of concrete pavement parameters. The equipment was applied in three experimental sections with different concrete pavements built at the University of Sao Paulo campus. The ultrasonic signal processing is given. The results analysis enables the efficient and reliable identification of thickness and reinforcement position within the concrete slab. Construction problems were evidenced in one of experimental sections with thickness deficiencies and reinforcement in a position below projected. Furthermore, the use of a novel concrete quality indicator was correlated with the presence of transverse cracks and alkali-silica reaction within the sections.

Ultrasonic pitch and catch technique for non-destructive testing of reinforced concrete slabs

“…These discrepancies may be caused by the uneven surface of the RC slabs. Similar observations were reported by other researchers [8,23]. In Fig.…”

“…The ultrasonic technique (a.k.a. acoustic-based method) is the most applied imaging methods in medicine and has been used successfully for many years to evaluate metallic and composite materials [15,23]. First tests on concrete specimens using the ultrasonic (UT) methods began in the early 1990s.…”

“…Two-sided UT testing methods require the coupling of transmitters and receivers in two sides of structures with couplants and gels, which may not be applicable in the field because of limitations in physical coupling and surface preparation [23]. Further, the UT wave is attenuated when propagating through a large concrete structure, and small inclusions cannot be captured [7].…”

Strength of Concrete through Ultrasonic Pulse Velocity and Uniaxial Compressive Strength

“…The UPV method is characterized by its application to evaluate the quality of concrete (Ramadhansyah et al, 2011;ACI, 2013;ASTM, 2016). The noninvasive scanning technique of UPV measurement consists of determining the velocity of an ultrasonic wave that travels through the concrete, estimating the compressive strength of the concrete using correlations (ASTM, 2016;Orozco et al, 2020) without altering the physical or chemical properties of the concrete (Suárez, 2004;Benítez-Herreros, 2011;Salles et al, 2017;Pedreros et al, 2020). These types of waves are acoustic pressure waves with frequencies higher than those of the auditory spectrum of the human ear (Edwin, 2005;Martinez et al, 2007).…”

Avaliação da relação entre variação de espessura da placa de concreto e presença de defeitos em pavimentos de concreto

“…As ondas de baixa frequência geradas pelos transdutores distribuem-se através do pavimento de concreto sendo re"letidas em um ponto de descontinuidade acústica. As posições de alta intensidade são descritas como uma mudança na impedância acústica, que pode ser uma interface de duas camadas, danos ao concreto, delaminação ou até barras da armadura de liga-ção ou de transferência (HOEGH et al, 2012;HOEGH et al, 2013;SALLES et al 2017). Em uma pesquisa proposta por Vancura et al (2013), em que o objetivo principal foi avaliar se os corpos de prova extraıdos segundo às diretrizes normativas do MnDOT representariam "ielmente a variação da espessura do pavimento de concreto, comparou-se as informações de espessura obtidas a partir da tomogra"ia ultrassônica (MIRA) e àquelas oriundas da perfuração de corpos de prova.…”