Effect of fly-ash as fine aggregate on the workability and mechanical properties of cemented paste backfill

Yin, Shenghua; Yan, Zepeng; Chen, Xun; Wang, Leiming

doi:10.1016/j.cscm.2022.e01039

Cited by 19 publications

(13 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…% FA is 77.69 MPa, 74.61 MPa, 73.79 MPa, 71.71 MPa, respectively, showing a monotonic decreasing trend. Such phenomenon is consistent with normal concrete with FA as supplementary cementitious materials, especially at early ages [ 28 ]. As for flexural strength, the weakening effect is slightly mitigated, even when the ratio of FA/(FA + ASR) reaches 0.67, the flexural strength of the above four groups after curing for 28 days is 17.88 MPa, 17.16 MPa, 17.34 MPa 15.96 MPa, respectively.…”

Section: Moc Pastes With Fa and Asrsupporting

confidence: 85%

“…The reduction rates are 12.5%, 22.04%, 29.32% and 37.50% for Groups A1, A2, A3 and A4, respectively. Possible reasons lie in the increase in solid inert powder dosage and the decrease in water in the whole system [ 28 , 29 ], reflected by mix proportions in Table 2 . Furthermore, the smaller average particle size of FA particles (14.39 μm) than caustic burnt magnesia powder (20.82 μm) is also responsible for the lower flowability due to higher water demand for wrapping micro solid particles.…”

Section: Role Of Fly Ash In Moc Pastesmentioning

confidence: 99%

“…Such improvements are also observed in Series D and E containing more FA in the system. Better fluid performance displayed in Series C, D and E can be ascribed mainly to the lubricating effect of spherical FA particles [ 28 ]. On the condition that the total weight of FA and ASR maintains the same, the increase in FA content leads to higher flowability, benefiting not only the in situ construction but also enhancing the microstructure and durability of the composites.…”

Section: Moc Pastes With Fa and Asrmentioning

confidence: 99%

See 2 more Smart Citations

Eco-Sustainable Magnesium Oxychloride Cement Pastes Containing Waste Ammonia Soda Residue and Fly Ash

et al. 2022

View full text Add to dashboard Cite

Magnesium oxychloride cement (MOC), a type of special construction material, has drawn much research attention in solid waste utilization and environmental protection due to its eco-friendly production. Ammonia soda residue (ASR), a by-product generated from sodium carbonate manufacturing, is one of the industrial wastes that can be recycled in MOC systems. However, ASR exhibits adverse effects on the fresh performance and volume stability of MOC pastes. This paper aims at improving the properties of ASR-MOC by introducing fly ash (FA), solid waste from the power industry. Firstly, the roles of FA in MOC pastes are evaluated and analyzed. Then, three substitution ratios of FA (33.3%, 50% and 66.7% in weight) for ASR are designed for MOC pastes with 10% to 40% industrial wastes. Flowability, setting, strength and expansion of all mixtures were experimentally studied. Furthermore, X-ray diffraction (XRD) and scanning electron microscope (SEM) approaches were adopted to illustrate the microstructure changes. Results show that by adding different amounts of FA, the inferior flowability of MOC caused by ASR can be improved by 6–23%, the setting process can be prolonged by 30–55% and the expansion ratio can be reduced by 14–66%. The intensity of characteristic peaks of 5-phase and Mg(OH)2, together with the degrees of crystallization in XRD curves, well explain the strength variation and volume stability of ASR-MOC pastes. According to the regulation of relative specification, up to 20% of solid wastes in weight (10% FA + 10% ASR) can be consumed, contributing greatly to the greener sustainable development of construction materials.

show abstract

Section: Moc Pastes With Fa and Asrsupporting

confidence: 85%

Section: Role Of Fly Ash In Moc Pastesmentioning

confidence: 99%

Section: Moc Pastes With Fa and Asrmentioning

confidence: 99%

See 1 more Smart Citation

Eco-Sustainable Magnesium Oxychloride Cement Pastes Containing Waste Ammonia Soda Residue and Fly Ash

et al. 2022

View full text Add to dashboard Cite

show abstract

“…As a fine aggregate, FA can effectively improve the gradation performance of the mixture. Short-term (3d/7d) strength increased with the increase of FA content, while long-term (28d) strength and slump increased first and then decreased [97].…”

Section: Fly Ashmentioning

confidence: 90%

Using Chinese Coal Gangue as an Ecological Aggregate and Its Modification: A Review

et al. 2022

View full text Add to dashboard Cite

Coal gangue is a kind of industrial solid waste with serious ecological and environmental implications. Producing concrete with coal gangue aggregate is one of the green sustainable development requirements. This paper reviews the properties and preparation methods of Chinese gangue aggregate, studies the influence of gangue aggregate on concrete properties and the prediction model of gangue concrete, and summarizes the influence of modified materials on gangue concrete. The studies analyzed in this review show that different treatments influence the performance of coal gangue aggregate concrete. With the increase in the replacement ratio of coal gangue aggregate in concrete, the concrete workability and mechanical performance are reduced. Furthermore, the pore structure changes lead to decreased porosity, greatly affecting the durability. Coal gangue is not recommended for producing high-grade concretes. Nevertheless, pore structure can be improved by adding mineral admixtures, fibers, and admixtures to the coal gangue concrete. Hence, the working properties, mechanical properties, and durability of the concrete can be improved effectively, ensuring that coal gangue concrete meets engineering design requirements. Adding modified materials to coal gangue concrete is a viable future development direction.

show abstract

“…The slump and expansion of each proportioned material in Table 5 were tested. In addition, the results show that the slump and expansion of the 9 proportions are 240~268 mm and 410~620 mm, respectively [ 28 ]. The flow performance can meet the requirements of engineering practice.…”

Section: Methodsmentioning

confidence: 99%

The Mechanical Properties of Gangue Paste Material for Deep Mines: An Experimental and Model Study

et al. 2022

View full text Add to dashboard Cite

Gangue paste material is mainly composed of coal gangue with particle size, which is mixed with cement. Fly ash and additives can be added to change its performance. In this paper, the influence of each component on the mechanical properties of gangue paste material was studied by an orthogonal experiment. The conversion relationship among various indexes of mechanical properties of gangue paste material and the response surface prediction model were discussed. The results show that the mechanical properties of gangue paste materials are positively correlated with the content of cement, the content of fly ash and the mass concentration, which increase with the increase of the three factors, and show the primary and secondary relationship of the content of cement > the content of fly ash > the mass concentration. A response surface prediction model of mechanical property parameters is established, which includes the first order term of the influencing factors of gangue paste material and the first order interaction term between any two factors. In the response surface prediction model of uniaxial compressive strength, splitting tensile strength, cohesion and elastic modulus, the goodness of fit test coefficients are 0.998, 0.957, 0.970 and 0.997, respectively, which proves that the model has good goodness of fit. The research results provide basic parameters for paste filling mining practice, and also provide the basis for numerical simulation of filling body value.

show abstract

Effect of fly-ash as fine aggregate on the workability and mechanical properties of cemented paste backfill

Cited by 19 publications

References 40 publications

Eco-Sustainable Magnesium Oxychloride Cement Pastes Containing Waste Ammonia Soda Residue and Fly Ash

Eco-Sustainable Magnesium Oxychloride Cement Pastes Containing Waste Ammonia Soda Residue and Fly Ash

Using Chinese Coal Gangue as an Ecological Aggregate and Its Modification: A Review

The Mechanical Properties of Gangue Paste Material for Deep Mines: An Experimental and Model Study

Contact Info

Product

Resources

About