Design and optimization of an instrument for measuring bughole rating of concrete surfaces

Özkul, Tarık; Küçük, İsmail

doi:10.1016/j.jfranklin.2010.04.004

Cited by 32 publications

(14 citation statements)

References 10 publications

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“…The bond strength between the successive layers of the SCC mix is generated by the proper mixing of both layers and the level of structural buildup at rest of concrete mix used in the first layer. The mechanism of bond failure can be determined after strength tests with digital image processing [ 8 , 23 ] or using an optical measuring device [ 24 ]. To determine the failure mechanism of the successive layers of the SCC mixture and the effectiveness of their mixing for each placement technology, the surfaces of the samples were examined after splitting tensile strength tests, using their close-shot photos.…”

Section: Resultsmentioning

confidence: 99%

Effect of Placement Technology on the Bond Strength Between Two Layers of Self-Compacting Concrete

Dybeł

Kucharska

2020

Materials

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Self-compacting concrete (SCC) should generally be placed continuously, but it is not uncommon for contractors to be forced to use interruptions in concrete works due to delivery delays. The multilayer casting of SCC can cause weak bond conditions in the contact area of subsequent layers. Methods of preventing cold joint or lift line formation for normal concretes are not suitable for self-compacting concretes. This article provides research on the effect of multilayer casting technology on the bond strength between two layers of SCC. Three technological variants of connecting successive layers of SCC mixture on beam elements were analyzed: The free flow of the mixture, dropping the mixture from a greater height, and mechanical disturbance of the first layer. Three delay times were applied: 30, 45, and 60 min between two layers of SCC. In general, the research revealed that, regardless of the multilayer casting variant, the bond strength between two layers decreased as the delay time was extended. The best performance and the lowest drop in bond strength were obtained for samples with a mechanically disturbed first layer, independent of the delay time. This method gave similar results to a reference element made without a break in concreting. It was also demonstrated that current recommendations and standard guidelines for multilayer casting appear to be insufficient for ensuring an adequate bond between layers.

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Section: Resultsmentioning

confidence: 99%

Effect of Placement Technology on the Bond Strength Between Two Layers of Self-Compacting Concrete

Dybeł

Kucharska

2020

Materials

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“…Many voids are visible on slabs 1 and 3. These voids (bugholes) typically result from the migration of entrapped air and to a less extent water, to the fresh concrete interfaces [ 43 , 44 ]. These voids and the roughness of the surfaces may weaken the local stiffness of the concrete or may influence the dynamic interaction at the material/transducer interface.…”

Section: Concrete Slabs Testsmentioning

confidence: 99%

On the Reliability of a Solitary Wave Based Transducer to Determine the Characteristics of Some Materials

Deng

Nasrollahi

Rizzo

et al. 2015

Sensors

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In the study presented in this article we investigated the feasibility and the reliability of a transducer design for the nondestructive evaluation (NDE) of the stiffness of structural materials. The NDE method is based on the propagation of highly nonlinear solitary waves (HNSWs) along a one-dimensional chain of spherical particles that is in contact with the material to be assessed. The chain is part of a built-in system designed and assembled to excite and detect HNSWs, and to exploit the dynamic interaction between the particles and the material to be inspected. This interaction influences the time-of-flight and the amplitude of the solitary pulses reflected at the transducer/material interface. The results of this study show that certain features of the waves are dependent on the modulus of elasticity of the material and that the built-in system is reliable. In the future the proposed NDE method may provide a cost-effective tool for the rapid assessment of materials’ modulus.

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“…Surface voids or bugholes, which are derived from the migration of an entrapped air bubble to the interface between fresh concrete and formwork [ 5 ] are considered to be one of the most seriously encountered defects on the concrete surface [ 6 ]. Visually, they correspond to scattered small pits and craters on the concrete surface after the process of formwork removal [ 7 ]. The existence of surface voids leads to many flaws, which are listed as follows.…”

Section: Introductionmentioning

confidence: 99%

Variable Selection from Image Texture Feature for Automatic Classification of Concrete Surface Voids

Zhao

Liu

Zhao

2021

Computational Intelligence and Neuroscience

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Machine learning plays an important role in computational intelligence and has been widely used in many engineering fields. Surface voids or bugholes frequently appearing on concrete surface after the casting process make the corresponding manual inspection time consuming, costly, labor intensive, and inconsistent. In order to make a better inspection of the concrete surface, automatic classification of concrete bugholes is needed. In this paper, a variable selection strategy is proposed for pursuing feature interpretability, together with an automatic ensemble classification designed for getting a better accuracy of the bughole classification. A texture feature deriving from the Gabor filter and gray-level run lengths is extracted in concrete surface images. Interpretable variables, which are also the components of the feature, are selected according to a presented cumulative voting strategy. An ensemble classifier with its base classifier automatically assigned is provided to detect whether a surface void exists in an image or not. Experimental results on 1000 image samples indicate the effectiveness of our method with a comparable prediction accuracy and model explicable.

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Design and optimization of an instrument for measuring bughole rating of concrete surfaces

Cited by 32 publications

References 10 publications

Effect of Placement Technology on the Bond Strength Between Two Layers of Self-Compacting Concrete

Effect of Placement Technology on the Bond Strength Between Two Layers of Self-Compacting Concrete

On the Reliability of a Solitary Wave Based Transducer to Determine the Characteristics of Some Materials

Variable Selection from Image Texture Feature for Automatic Classification of Concrete Surface Voids

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