An improved outer pipe method for expansive pressure measurement of static cracking agents

Xu, Shuai; Hou, Pengyuan; Li, Runran; He, Qingyuan

doi:10.1016/j.ijmst.2021.11.011

Cited by 21 publications

(9 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Therefore, failure of the expansion pressure test due to high-temperature burning of the strain gauges or holes should be avoided. The "Chinese SCDA Expansion Pressure Test Standard" specifies that the test pipe should be submerged in a constant-temperature water tank for testing [17]. The high thermal conductivity of steel and the large specific heat capacity of water can be used to absorb the heat released by the hydration reaction, thus obtaining the expansion stress throughout the reaction process.…”

Section: Introductionmentioning

confidence: 99%

“…The test recording process was simplified, and the accuracy of numerical recording was improved. Xu et al [17] fabricated thickened aluminum alloy cylinders to replace seamless steel tubes based on the outer tube method and tested the expansion pressure by recording the strain at the end surface of the cylinders. The thickened aluminum alloy cylinders increased the thermal conductivity paths and reduced the surface temperature of the cylinders.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Prevention of Blowout Tests in Large-Diameter Boreholes with Soundless Chemical Demolition Agents and Fracturing Characteristics of Hard Sandstones

Wu,

Dong,

Yuan

et al. 2024

Processes

View full text Add to dashboard Cite

Increasing the diameter of the drillhole can facilitate drillhole breakage using soundless chemical demolition agents, but it is prone to cause drillhole blowout, resulting in crushing failure. This paper conducted a blowhole prevention test on a large borehole using the internal insertion cooling pipe method (ICBPM) to test the expansion pressure of cooling pipes with different diameters. During this test, a fracture occurred in a hole with a 75 mm inner diameter in the rectangular sandstone specimens with high strength. It was found that utilizing the ICBPM can effectively hinder the development of blowholes. Expansion and blowhole prevention are optimized with a 0.14 mass ratio of the cooling water to demolition agent and a maximum expansion stress of 49.0 MPa. The guiding effect of the minimum resistance line is significant. In repeated tests, all fissures are distributed in a Y-shape on the free surface where the minimum resistance line is located. The acoustic emission signals from statically fractured hard rock increase abruptly before damage, and the development of rock expansion and fracturing can be obtained through strain monitoring. These results suggest that the ICBPM can reduce the expansion time with a strong crushing effect, satisfying the need to process more crushing projects.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Prevention of Blowout Tests in Large-Diameter Boreholes with Soundless Chemical Demolition Agents and Fracturing Characteristics of Hard Sandstones

Wu,

Dong,

Yuan

et al. 2024

Processes

View full text Add to dashboard Cite

show abstract

“…A relationship between crack force and crack ductility radius was obtained. Zheng [28], Xu [29], Zhao [30] and Garcia Calvo et al [31]. studied and analyzed the principle of static expansive agent and its influencing factors.…”

Section: Introductionmentioning

confidence: 99%

Numerical Simulation of Gas Extraction in Coal Seam Strengthened by Static Blasting

2022

View full text Add to dashboard Cite

For mines with low permeability and high gas emissions, static blasting technology is used to pre-split the coal seam to increase the permeability and strengthen the gas extraction, which will significantly reduce the occurrence of gas accidents in mines. Taking Wangjialing Coal Mine as the research object, the mathematical model of fluid-solid is established. The numerical simulation software COMSOL is used to simulate the established mathematical model. Simultaneously, the factors affecting the efficiency of static blasting gas extraction are analyzed by adjusting the parameters. The results reveal a more significant drop in gas pressure with increasing time. At 10 d, 30 d, 90 d and 180 d, the extraction efficiency increases by 11.80%, 18.67%, 22.22% and 24.13% in comparison to conventional extraction. In studying the influence of expansion pressure and other factors on gas extraction during static blasting, it is found that the change of negative pressure has little effect on gas extraction. Static blasting can significantly reduce gas pressure and achieve safe coal mining, providing a basis of field application of efficient gas extraction in low gas mines.

show abstract

“… 3 A large number of scholars at home and abroad have conducted a large number of experimental studies and found that the ratio of water agent, temperature, and pore size are the main factors affecting the expansion pressure of the static crushing agent. 4 − 8 Among them, temperature is the key factor affecting the speed and peak pressure of static crushing agent, and many other studies have shown that the higher the temperature, the faster the peak pressure is reached, and the peak expansion pressure can be increased by increasing the pore size and suitable water agent ratio. 9 , 10 The peak expansion pressure can be increased by increasing the pore size and suitable water agent ratio.…”

Section: Introductionmentioning

confidence: 99%

“…Toshio Kono was the first to conduct theoretical research on expansion agents, pointing out that the magnitude of expansion pressure depends on the growth of Ca(OH) 2 crystals and finding that the ambient temperature and the thermal conductivity of the crushed material are the main factors affecting their growth . A large number of scholars at home and abroad have conducted a large number of experimental studies and found that the ratio of water agent, temperature, and pore size are the main factors affecting the expansion pressure of the static crushing agent. − Among them, temperature is the key factor affecting the speed and peak pressure of static crushing agent, and many other studies have shown that the higher the temperature, the faster the peak pressure is reached, and the peak expansion pressure can be increased by increasing the pore size and suitable water agent ratio. , The peak expansion pressure can be increased by increasing the pore size and suitable water agent ratio. Some scholars focused on the improvement of temperature on the reaction efficiency of static breakers, indicating that the reaction rate can be changed by increasing the temperature. , …”

Section: Introductionmentioning

confidence: 99%

Mechanistic Study of a Microwave Field-Controlled Static Crushing Agent for Efficient Rock Breaking

Liu

Guan

et al. 2022

ACS Omega

View full text Add to dashboard Cite

The long reaction time and uncontrollable reaction process of the swelling agent in the process of rock breaking by static crushing agent lead to unsatisfactory efficiency and effect of rock breaking. This paper uses physical experiments to compare and analyze the changes in temperature and pressure of the hydration reaction under different microwave conditions; utilizes microscopic analysis of the hydration reaction products under each condition, combined with numerical calculations to elucidate the mechanism of the effect of microwave field on the hydration reaction of the expansion agent; and proposes a microwave field-controlled static crushing agent rock-breaking method. The study reached the following main conclusions: (1) microwave heating is better than conventional heating in terms of heating rate, peak temperature, and peak pressure; (2) using static crushing agent rock breaking is preferable to use a low-power microwave field to control the reaction process, and to ensure that the initial temperature is not higher than the local water boiling point; (3) microwave heating to promote the reaction mechanism lies in its deep heating of the system, faster heating rate, and higher energy utilization, and is more conducive to hydration expansion reaction; (4) selective heating of microwaves can enhance the hydration reaction of calcium oxide and inhibit the production of hydrated tricalcium silicate, making the reaction more complete, while microwave heating will also improve the microstructure of hydration products.

show abstract

An improved outer pipe method for expansive pressure measurement of static cracking agents

Cited by 21 publications

References 31 publications

Prevention of Blowout Tests in Large-Diameter Boreholes with Soundless Chemical Demolition Agents and Fracturing Characteristics of Hard Sandstones

Prevention of Blowout Tests in Large-Diameter Boreholes with Soundless Chemical Demolition Agents and Fracturing Characteristics of Hard Sandstones

Numerical Simulation of Gas Extraction in Coal Seam Strengthened by Static Blasting

Mechanistic Study of a Microwave Field-Controlled Static Crushing Agent for Efficient Rock Breaking

Contact Info

Product

Resources

About