Controlled Cracking for Industrial Concrete Waste by Steam Pressure Cracking Agent

Kamiya, Osamu; Suzuki, Kaito; Okuyama, Etsushi; Kojima, Naoya; Ito, Shin‐ichi; Takahashi, Mamoru; Murata, Kenji; Kazumi, Takashi; Maisawa, Arata; Nakatsu, Masanobu; Mizuma, Hiroyuki; Sodeyama, Hiroshi; Iwama, Yuichi; Furuuchi, Nobuyasu; Shinya, Keizo

doi:10.5188/ijsmer.24.18

Cited by 5 publications

(17 citation statements)

References 10 publications

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“…Using 240 g of this SPC agent, the size was 1.0×1.0×0.5 m 3 . Concrete was crushed [3], and the obtained sample is shown in Figure 1.…”

Section: Dismantling Concrete Samplesmentioning

confidence: 99%

“…The demolition of concrete by a steam pressure cracking (SPC) [1] agent can enable the dismantling of concrete safely and quickly [2][3][4] because there is less vibration than in the blasting method using explosives [5]. An SPC agent was developed by Nippon Koki Co. Japan and contributes to recycling technology [6][7][8] from the EDG's [9] viewpoint.…”

Section: Introductionmentioning

confidence: 99%

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Elastic Wave Property of Concrete Decomposed by Steam Pressure Cracking Agent

Kamiya¹,

Okuyama²,

Takahashi³

et al. 2022

J. Mater. Appl.

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A steam pressure cracking (SPC) agent is a method that can dismantle concrete safely and quickly. In previous studies, the authors showed that the direction of the crack could be controlled by the tensile stress at the induction holes and not by the compressive stress at the SPC hole. We demonstrate that the compression elastic wave changes to a tensile wave when the wave is reflected at the free surface of the induction hole. We also examined the properties of the concrete by developing an elastic wave measuring system that is difficult to break down even in high-temperature, wet, and radiation environment. The elastic wave velocity change in the four concrete types was less than 4%. It was found that the standard deviation value, σ, changed four times. Therefore, it is possible to determine the deterioration of the internal structure of concrete using the standard deviation value σ, which indicates the dispersion of the elastic wave velocity.

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“…Using 240 g of this SPC agent, the size was 1.0×1.0×0.5 m 3 . Concrete was crushed [3], and the obtained sample is shown in Figure 1.…”

Section: Dismantling Concrete Samplesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Elastic Wave Property of Concrete Decomposed by Steam Pressure Cracking Agent

Kamiya¹,

Okuyama²,

Takahashi³

et al. 2022

J. Mater. Appl.

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show abstract

“…The purpose of this study was to develop a total remote demolition system that is safe and does not cause environmental problems. Therefore, the authors focus on developing a remote mechanical system consisting of a positioner, drilling and insert, and a steam pressure cracking agent (SPC) [3,4]. Explosive agents generate many fine particles [4] and cause secondary contamination, so they cannot be used for the dismantling of nuclear reactors.…”

Section: Introductionmentioning

confidence: 99%

“…Therefore, the authors focus on developing a remote mechanical system consisting of a positioner, drilling and insert, and a steam pressure cracking agent (SPC) [3,4]. Explosive agents generate many fine particles [4] and cause secondary contamination, so they cannot be used for the dismantling of nuclear reactors. SPC is nonexplosive and thermite reaction agent.…”

Section: Introductionmentioning

confidence: 99%

“…Most conventional nonexplosive blasting techniques are static chemical reaction agent that causes compressive pressure [5], but it takes long time, several hours, to break the concrete. Therefore, remote systems using SPC have advantages over another reinforced concrete cracking methods, such as rapid, safe, and controlled [4] crack propagation. In this study, the steam pressure cracking system operation and cracking characteristics of large concrete structures using an SPC were elucidated using experimental analysis.…”

Section: Introductionmentioning

confidence: 99%

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Demolition of Reinforced Concrete by Steam Pressure Cracking System

Kamiya¹,

Takahashi²,

Miyano³

et al. 2022

J. Mater. Appl.

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The authors developed an environment-friendly demolition mechanical system for a large reinforced concrete structure for an actual site. The steam pressure cracking agent (SPC, non-explosive) is a method that can safely and quickly separate concrete because it produces lesser vibration and sound than the blasting method, which uses explosives. The authors showed that the direction of cracking can be controlled by an induction hole. The principle of control is that the elastic wave of the compression stress generated from the SPC reaction changes to a tensile elastic wave at the induction hole, which initiates a crack. Furthermore, in the SPC method, a large amount of concrete powder generated by the explosion method was not produced, and there was no risk of secondary contamination by fine concrete powder. The area over which the crack propagated depends on the energy generated from the SPC. The relationship between the two is linear. For reinforced concrete, the energy of the SPC is used for both the destructive energy of the concrete and the energy of the cutting of the reinforcing steel bar, which quickly breaks with low energy. By applying an SPC to dismantle large reinforced concrete structures, controlled cracking can be achieved safely and quickly without any environmental pollution. A fracturing method using a SPC is an effective method for the decommissioning of nuclear power plants and the dismantling of concrete structures. In this report, we report a remote drilling system that can be used to remotely install loading holes and guiding holes for the SPC and perform effective controlled fracturing.

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Cracking Methods for Testing of Self-Healing Concrete: An Experimental Approach

Medeiros,

Di Sarno

2024

Buildings

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With the advent of new sustainable construction materials, self-healing concrete has been used and tested in the last decade, raising the question of the efficacy of said mechanisms to prevent water permeation after crack formation. Thus, new novel mechanical methodologies have been introduced to induce controlled cracks in concrete specimens to improve the standardisation and effectiveness of permeability tests. This research explores those new mechanical techniques to create consistent and reproducible crack patterns, crucial for assessing the efficacy of self-healing mechanisms in concrete. This study systematically evaluates how different crack configurations influence the self-healing ability of the material. Findings from this research are expected to aid in refining testing protocols and to contribute significantly to the field of material science within civil engineering by demonstrating the potential of self-healing concrete to revolutionise building practices.

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Controlled Cracking for Industrial Concrete Waste by Steam Pressure Cracking Agent

Cited by 5 publications

References 10 publications

Elastic Wave Property of Concrete Decomposed by Steam Pressure Cracking Agent

Elastic Wave Property of Concrete Decomposed by Steam Pressure Cracking Agent

Demolition of Reinforced Concrete by Steam Pressure Cracking System

Cracking Methods for Testing of Self-Healing Concrete: An Experimental Approach

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