Stress–strain behaviour and acoustic emission characteristic of gangue concrete under axial compression in frost environment

Guan, Xiao; Qiu, Jisheng; Song, Huitao; Qin, Qing; Zhang, Chenghua

doi:10.1016/j.conbuildmat.2019.06.008

Cited by 54 publications

(18 citation statements)

References 21 publications

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“…The color changes to whitish gray and even red after spontaneous combustion or after being calcinated, according to its iron oxide content and weathering degree [2]. According to Chinese standard JGJ-52-2006, the physical properties of rock coal gangue (RCG) and spontaneous-combustion coal gangue (SCG) vary from different origins in China, as summarized in Table 1 [12][13][14][15][16][17][18][19][20][21][22][23][24]. The apparent density of gangue is approximately 2600 kg/m 3 , which is similar to natural stone, while its bulk density is approximately 1200 kg/m 3 , which belongs to lightweight aggregate.…”

Section: Physical Propertiesmentioning

confidence: 99%

Application of Coal Gangue as a Coarse Aggregate in Green Concrete Production: A Review

Gao

Guo

2021

Materials

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Among the techniques for converting stacked coal gangue to reusable material, one of the most effective ways is to use coal gangue as a coarse aggregate in green concrete productions. The physical and chemical properties of rock and spontaneous-combustion coal gangue are generally suitable for being used as a coarse aggregate in green concrete. Coal gangue concrete is not recommended to be used in subsurface structures, as its water absorption law would be changed under a large replacement ratio. The mechanical performance of coal gangue concrete is degraded by raising the replacement ratio. Over-low and -high concrete grades are not suggested to be used as coal gangue aggregate, unless extra admixtures or specific methods are used. The influence of coal gangue on the durability of coal gangue concrete is remarkable, resulting from the porous structure of coal gangue that provides more transmission channels for air and liquid in concrete, but is beneficial for thermal insulation. The usage of coal gangue in structural concrete members is still limited. The mechanical behavior of some structural members using coal gangue concrete has been reported. Among them, concrete filled steel tubes are a preferable configuration for using coal gangue concrete, regarding both the mechanical and durability performance.

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Section: Physical Propertiesmentioning

confidence: 99%

Application of Coal Gangue as a Coarse Aggregate in Green Concrete Production: A Review

Gao

Guo

2021

Materials

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“…Studies have shown that the dynamic elastic modulus was signicantly reduced with the expansion of the microscopic pore structure inside the concrete during freeze-thaw cycles [23]. Meanwhile, the peak stress decreased and the peak strain increased [24]. By nding the partial derivative of the stress corresponding to the change in equation 4, the distribution of elastic modulus for each point in the stress-strain space was obtained as follows:…”

Section: Application For Stress-strain Curved Surface Equationmentioning

confidence: 99%

Equation for the Degradation of Uniaxial Compression Stress of Concrete due to Freeze-Thaw Damage

Yang

Wang

Gao

et al. 2019

Advances in Materials Science and Engineering

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To study the freeze-thaw damage characteristics of concrete, the uniaxial compressive tests of concrete under different number of freeze-thaw cycles were conducted, and the damage variable of freeze-thaw was obtained. The test results showed that the stress was a function of strain and freeze-thaw damage variable, and it can describe the degradation of concrete strength. Meanwhile, the equation for the stress-strain curved surface about strain and freeze-thaw damage variable was also proposed in this paper. The derivative function of the stress-strain curved surface equation with respect to strain presented the change of elastic modulus with the increase of freeze-thaw cycle number. Equation proposed in this paper can be used for predicting the concrete lifetime effectively in cold and large temperature difference regions.

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“…It is required that the freeze-thaw damage evolution model is in good agreement with the actual experimental data, which can effectively reflect the freeze-thaw damage development process of CGC in the freeze-thaw environment. However, Guan et al [18] found that when the gangue replacement rate increased from 0% to 60%, the frost resistance of coal gangue concrete was significantly reduced, and the physical and mechanical properties of coal gangue concrete decreased with the extension of the freeze-thaw cycle time [19]. At the same time, Luo et al [20] studied the influence of steel fiber content and shape on the compressive strength and split tensile strength of coal gangue concrete after freezing and thawing.…”

Section: Introductionmentioning

confidence: 99%

Study on Mechanical Properties of PET Fiber-Reinforced Coal Gangue Fine Aggregate Concrete

Huang

Zhou

2021

Geofluids

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In recent years, with the rapid development of the construction industry, the demand for natural river sand has become increasingly prominent. Development of alternatives to river sand has become an interesting direction for concrete research. In this paper, coal gangue was proposed to replace part of the river sand to produce coal gangue fine aggregate concrete, while waste polyethene terephthalate (PET) bottles were used as raw materials to make PET fibers to improve the mechanical properties of coal gangue fine aggregate concrete. There were two parts of the test conducted. In the first part, the compressive strength of the gangue fine aggregate concrete cube, splitting tensile strength, axial compressive strength, and static elastic modulus were studied when the substitution rate of coal gangue increased from 0% to 50%. Referring to the equation of the full stress-strain curve of plain concrete, the stress-strain constitutive equation of coal gangue fine aggregate concrete was analyzed and studied. By comparing with plain concrete, it was found that the coal gangue concrete with a replacement rate of 50% had higher compressive strength and tensile strength, but its brittleness was significantly greater than that of plain concrete in the later stage. In the second part, by studying the effect of different PET fiber content on the mechanical properties of coal gangue fine aggregate concrete with a replacement rate of 50%, it was found that when the addition of PET fiber was 0.1% and 0.3%, not only were compressive strength, splitting tensile strength, static elastic modulus, and flexural strength of the gangue fine aggregate concrete effectively improved but also the brittleness of concrete can be significantly reduced. The study found that after adding 0.3% PET fiber, the coal gangue fine aggregate concrete with a replacement rate of 50% has better mechanical properties and less brittleness.

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Stress–strain behaviour and acoustic emission characteristic of gangue concrete under axial compression in frost environment

Cited by 54 publications

References 21 publications

Application of Coal Gangue as a Coarse Aggregate in Green Concrete Production: A Review

Application of Coal Gangue as a Coarse Aggregate in Green Concrete Production: A Review

Equation for the Degradation of Uniaxial Compression Stress of Concrete due to Freeze-Thaw Damage

Study on Mechanical Properties of PET Fiber-Reinforced Coal Gangue Fine Aggregate Concrete

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