Experimental study of indirect tensile strength of calcareous coal gangue mixture

Zhang, Yapeng; Meng, Wenqing; Zhang, Zhifei

doi:10.1260/1708-5284.10.5.457

Cited by 3 publications

(3 citation statements)

References 5 publications

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“…Zhang Zongtang [41] studied the influence of grading on the compaction and characteristics of coal gangue roadbed filling. It has been found that the compaction characteristics of coal gangue roadbed filling have a significant impact on the grading.…”

Section: Used As Subgrade Materialsmentioning

confidence: 99%

Present situation of comprehensive utilization of coal-based solid waste

2024

E3S Web Conf.

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At present, the annual discharge of coal-based solid waste in China has exceeded 800 million tons, but the mainstream treatment methods are still simple treatment methods such as goaf backfilling and openpit stacking. The massive stacking of coal-based solid waste is not only a serious waste of resources itself, but also brings a series of problems such as environmental pollution. Under the “Carbon Peak” and “Carbon Neutrality” strategy in China, in order to achieve green and rapid development of the coal industry, it is necessary to solve the problem of coal-based solid waste treatment and achieve green and comprehensive utilization of coal-based solid waste. Taking coal gangue, gasification slag and fly ash as representative coal-based solid waste, the present situation of coal-based solid waste production in China and the basic properties of coal-based solid waste are introduced. The utilization status and application characteristics of coal-based solid waste in cement concrete, roadbed materials, soil improvement and so on are focused on, and the resource utilization potential of coal-based solid waste is analyzed and summarized. Then the application prospect of coal-based solid waste in high-value utilization in the future is analyzed and prospected.

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Section: Used As Subgrade Materialsmentioning

confidence: 99%

Present situation of comprehensive utilization of coal-based solid waste

2024

E3S Web Conf.

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“…rough the range analysis, it can be found that, in terms of stability, for coal gangue emulsified asphalt mixture, the order of the influence degree of each factor is water consumption > coal gangue content > emulsified asphalt dosage [21]. e preliminary analysis is that because the emulsified asphalt mixture is different from the hot mix asphalt mixture, the water consumption is very important to the compaction process of the asphalt mixture, and the insufficient water consumption can easily lead to the early demulsification of the asphalt mixture and the poor overall performance of the mixture and then affect the stability of the mixture.…”

Section: Analysis Of Influencing Factorsmentioning

confidence: 99%

Study on the Parameter Optimization and Strength Mechanism of Coal Gangue Emulsified Asphalt Mixture

Liu

Zhang

2020

Advances in Materials Science and Engineering

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Emulsified asphalt mixture has the characteristics of convenient construction and durable performance, but its poor early strength and demulsification seriously restrict the popularization and application of this material. At present, the coal gangue produced by coal-fired power plants is generally discarded, resulting in serious environmental pollution. The combination of coal gangue and emulsified asphalt can explore an efficient utilization way for more and more coal gangue and also solve the curing problem of asphalt. In order to give full play to the advantages of existing materials and make rational use of resources, this paper studies the factors affecting the performance of coal gangue emulsified asphalt mixture based on orthogonal experimental design and optimizes its material composition parameters by considering the coupling effect of two factors. The water stability of coal gangue emulsified asphalt mixture is evaluated by the immersion Marshall test. Finally, the strength formation mechanism of coal gangue emulsified asphalt mixture is analyzed from the microscopic point of view. The results determined 7.5% as the optimum amount of emulsified asphalt in coal gangue emulsified asphalt mixture and recommended the best parameter combination of 7.5% emulsified asphalt, 6% coal gangue, and 5% water consumption. With the increase of coal gangue content, the water loss resistance of emulsified asphalt mixture increases gradually, and the water stability of emulsified asphalt mixture can be improved by adding coal gangue. According to the microscopic analysis, the strength of the mixture is formed by the joint action of emulsified asphalt and coal gangue, in which the hydration products of coal gangue and asphalt play the role of cementation and strength together. The ordinary emulsified asphalt mortar mainly contains CaCO3, which mainly plays the role of physical filling.

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“…The results demonstrated that selective crushing obviously reduced the crushing value and calorific value of coal gangue; however, after adding 10% fly ash, it played a buffer role in the base mixture, and the unconfined compressive strength increased by 30.9% to 3.52 MPa in 7 days. Zhang et al [11] prepared a mixture of calcareous coal gangue, fly ash, lime powder, and a small amount of cement in the Hanxing area and examined the influence. When the amount of lime powder was extremely high, the lime negatively impacted the cleavage strength of a calcareous coal gangue mixture.…”

Section: Introductionmentioning

confidence: 99%

Mechanical Properties of Furnace Slag and Coal Gangue Mixtures Stabilized by Cement and Fly Ash

Zhang

Yan

et al. 2021

Materials

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The mechanical properties and strength formation mechanism of cement–fly-ash-stabilized slag–coal gangue mixture were examined using an unconfined compressive strength test, splitting strength test, triaxial test, and scanning electron microscopy to solve the limitations of land occupation and environmental pollution that is caused by fly ash from the Xixia District thermal power plant in Yinchuan, slag from the Ningdong slag yard, and washed coal gangue. Its performance as a pavement base mixture on the road was investigated. The results demonstrated that as the slag replacement rate increased, the maximum water content increased while the maximum dry density decreased. The addition of slag reduced the unconfined compressive strength and splitting strength of the specimens; furthermore, the higher the slag substitution rate, the lower the unconfined compressive strength and splitting strength of the specimens. As the cement content increased, the specimen’s unconfined compressive strength increased. Based on the principle of considering the mechanical properties and economic concerns, the slag replacement rate in the actual construction should be ~50% and should not exceed 75%. Based on the relationship between the compressive strength and splitting strength of ordinary concrete, the relationship model between the unconfined compressive strength and splitting strength of cement–fly-ash-stabilized slag–coal gangue was established. The failure mode, stress–strain curve, peak stress, and failure criterion of these specimens were analyzed based on the triaxial test results, and the relationship formulas between the slag substitution rate, cement content, peak stress, and confining pressure were fitted. As per the SEM results, the mixture’s hydration products primarily included amorphous colloidal C-S-H, needle rod ettringite AFt, unhydrated cement clinker particles, and fly ash particles. The analysis of the mixture’s strength formation mechanism showed that the mixture’s strength was the comprehensive embodiment of all factors, such as the microaggregate effect, secondary hydration reaction, and material characteristics.

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Experimental study of indirect tensile strength of calcareous coal gangue mixture

Cited by 3 publications

References 5 publications

Present situation of comprehensive utilization of coal-based solid waste

Present situation of comprehensive utilization of coal-based solid waste

Study on the Parameter Optimization and Strength Mechanism of Coal Gangue Emulsified Asphalt Mixture

Mechanical Properties of Furnace Slag and Coal Gangue Mixtures Stabilized by Cement and Fly Ash

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