Acoustically Assessed Influence of Air Pore Structure on Failure of Self-compacting Concretes Under Compression
08 Feb 2012-Journal of Civil Engineering and Management (Taylor & Francis Group)-Vol. 18, Iss: 1, pp 60-70
TL;DR: In this article, the authors investigated the influence of pore structure on the failure of self-compacting concretes modified with superplasticizers commonly used in construction and showed that there is a relationship between the pore structures parameters and the levels of cracking initiating stress and critical stress.
Abstract: The paper presents the results of investigations into the influence of pore structure on the failure of self-compacting concretes modified with superplasticizers commonly used in construction. Pore structure examinations were carried out in practically the whole range of pore diameters by means of an image analyzer and a mercury porosimeter. The failure of the self-compacting concretes under compression, was investigated by the acoustic emission technique and other methods. The levels of cracking initiating stress σi and critical stress σcr, demarcating the different stages in the failure process, were determined. It has been shown that there is a relationship between the pore structure parameters and the levels. The fatigue strength of the self-compacting concretes was calculated from the experimental results and on this basis the suitability of the concretes for structures subject to cyclic loads was determined.
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TL;DR: In this article, the capabilities of ultrasonic tomography for locating defects and determining their size in unilaterally accessible concrete members and for estimating the thickness of such members are described, and an original test methodology developed for this purpose is included.
82 citations
TL;DR: In this article, the results of studies of a total of 11 series of self-compacting concrete, which were modified with different amounts of the following nanoparticle additives: SiO2, TiO2 and Al2...
60 citations
TL;DR: In this paper, the authors presented a new nondestructive way of identifying the values of pull-off adhesion between the concrete layers in concrete floors based on the roughness parameters of the base layer surface.
Abstract: This paper presents a new nondestructive way of identifying the values of pull-off adhesion between the concrete layers in concrete floors. It based on the roughness parameters of the base layer surface, using the nondestructive optical technique, and on the floor surface, using the nondestructive acoustic techniques and employing artificial neural networks (ANNs) for this purpose. The new way has a potential for being widely used in practice, whereby it may become possible to employ previously trained ANNs to identify the pull-off adhesion, without impairing the surface of the tested concrete floor.
41 citations
Cites background from "Acoustically Assessed Influence of ..."
...…reports it also appears that nondestructive techniques can be useful in determining the bond between concrete layers (Bungey et al. 2006; Darowicki et al. 2003; Gołaski et al. 2012; Gorzelańczyk 2012; Grzelka et al. 2012; Helmerich et al. 2012; Hoła, Schabowicz 2010; Maierhofer et al. 2004)....
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TL;DR: In this paper, the radial basis function (RBF) artificial neural network was used to evaluate the pull-off adhesion of the top layer to the base layer in concrete floors by means of the parameters evaluated by the non-destructive acoustic impulse response technique and the nondestructive optical laser triangulation method.
Abstract: The interlayer bond is one of the primary qualities assessed during an inspection of floor concrete workmanship. The measure of this bond is the value of pull-off adhesion f b determined in practice by the pull-off method. The drawback of this method is that the tested floor is damaged in each of the test points and then needs to be repaired. This drawback can be overcome by developing a way which will make it possible to test floors in any point without damaging them locally. In this paper it is proposed to evaluate the pull-off adhesion of the top layer to the base layer in concrete floors by means of the radial basis function (RBF) artificial neural network using the parameters evaluated by the non-destructive acoustic impulse response technique and the non-destructive optical laser triangulation method. Presented RBF neural network model is useful tool in the non-destructive evaluation of the pull-off adhesion of concrete floor layers without the need to damage the top layer fragment from the...
29 citations
Cites background from "Acoustically Assessed Influence of ..."
...Literature reports indicate that also acoustic methods can be useful for assessing the pull-off adhesion of the concrete layers in floors (Beutel et al. 2008; Cerniglia et al. 2010; Gorzelańczyk 2012; Goszczyńska et al. 2012; Hoła, Schabowicz 2010; Matsuyama et al. 2010)....
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TL;DR: In this paper, a technology for ultrasonic tomography aimed at the detection of flawed zones in unilaterally accessible concrete structures and the determination of their thickness and coordinates was presented, and the construction of tomograms was described step by step.
Abstract: A technology for ultrasonic tomography aimed at the detection of flawed zones in unilaterally accessible concrete structures and the determination of their thickness and coordinates was presented. The construction of tomograms was described step by step. The results obtained by the current and previous tomograph variants were given. The tomograms of concrete specimens with specified model flaws and without them were obtained. Results with a lower noise level were obtained using the current tomograph variant. The need for the processing of a set of signals for the diagnostics and monitoring of concrete objects was shown.
25 citations
References
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TL;DR: Ozawa and Maekawa as mentioned in this paper developed a self-compacting concrete, which can be compacted into every corner of a formwork, purely by means of its own weight and with out the need for vibrating compaction.
Abstract: Development of Self-Compacting Concrete For several years beginning in 1983, the problem of the durability of concrete structures was a major topic of interest in Japan. The creation of durable concrete structures requires adequate compaction by skilled workers. However, the gradual reduction in the number of skilled workers in Japan's construction industry has led to a similar reduction in the quality of construction work. One solution for the achievement of durable con- crete structures independent of the quality of construc- tion work is the employment of self-compacting con- crete, which can be compacted into every corner of a formwork, purely by means of its own weight and with- out the need for vibrating compaction (Fig. 1). The necessity of this type of concrete was proposed by Okamura in 1986. Studies to develop self-compacting concrete, including a fundamental study on the work- ability of concrete, have been carried out by Ozawa and Maekawa at the University of Tokyo (Ozawa 1989, Okamura 1993 & Maekawa 1999). The prototype of self-compacting concrete was first completed in 1988 using materials already on the mar- ket (Fig. 2). The prototype performed satisfactorily with regard to drying and hardening shrinkage, heat of hydration, denseness after hardening, and other proper- ties. This concrete was named "High Performance Con- crete" and was defined as follows at the three stages of concrete:
1,558 citations
"Acoustically Assessed Influence of ..." refers methods in this paper
...Determined rheological properties of concrete mixes Test method Tested parameter Requirements acc. to Li and Hwang (2003), Nagamoto and Ozawa (1999), Okamura and Ouchi (2003), European Project Group (2005) Test results Concrete mix symbol A/SA B/SA C/SV D/SV Abrams cone 500 mm diameter spread time…...
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TL;DR: In this article, the parameters needed to correctly model concrete under compound stress are described and illustrated using the Concrete Damaged Plasticity model included in the ABAQUS software.
323 citations
01 Jan 1999
TL;DR: In this article, a rational mix-design method and self-compactability testing methods have been carried out from the viewpoint of making it a standard concrete, and recommendations and manuals for selfcompacting concrete were also established.
Abstract: Self-compacting concrete was first developed in 1988 in order to achieve durable concrete structures. Since then, various investigations have been carried out and the concrete has been used in practical structures in Japan, mainly by large construction companies. Investigations for establishing a rational mix-design method and self-compactability testing methods have been carried out from the viewpoint of making it a standard concrete. Recommendations and manuals for self-compacting concrete were also established.
279 citations
TL;DR: A survey of state-of-the-art non-destructive diagnostic techniques of testing building structures and examples of their applications can be found in this article, where the authors focus on techniques suitable for: detecting defects invisible on the surface, estimating the depth of cracks, determining the dimensions of elements accessible from one side only and 2D and 3D imaging of reinforcement distribution in such elements.
201 citations
01 Jul 1981
176 citations
"Acoustically Assessed Influence of ..." refers background in this paper
...cracking initiating stress σi and critical stress σcr can be found in the literature (Beres 1971; Flaga 1995; Furtak 1997; Hsu 1981)....
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