Effect of Hydration Process on Properties and Microstructure of Coal Gangue Admixture Concrete|RISS 상세보기

다국어 초록 (Multilingual Abstract)

The mineral of coal gangue is mainly kaolinite, which can be used as mineral admixture after activation. In order to study the effect of coal gangue on the hydration process of concrete, 20% coal gangue powder was used to replace cement to prepare concrete. The phase composition, microstructure morphology and pore structure of concrete hydration products at different ages were observed by X-ray diffraction (XRD), fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM) and nuclear magnetic resonance (NMR). At the same time, the experimental study on the compressive strength, splitting tensile strength and flexural strength of coal gangue admixture concrete with time and relationship was carried out. The results indicate that the addition of coal gangue powder significantly affected the hydration process of cement. In the cement-coal gangue powder-water system, coal gangue particles adsorbed a large amount of CH generated by cement hydration after curing for 14 d. The (AlO4)4− group in the coal gangue power replaced the (SiO4)4− on the calcium silicate hydrate (C-S-H) structure of the hydration product, thereby generating a new flocculated polymer calcium aluminosilicate hydrate (C-A-S-H). Until the curing age exceeded 56 d, the CH content in the slurry was less, and the hydration reaction rate of coal gangue became slowe. The unhydrated coal gangue particles played the “micro-aggregate effect”, filled in the pores and reduced the number of macropores and pores. The density of concrete microstructure increased, which promoted the continuous increase of concrete strength.

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참고문헌 (Reference)

1 Dellisanti F, "The role of microstrain on the thermostructural behaviour of industrial kaolin deformed by ball milling at low mechanical load" 102 : 69-77, 2012

2 Fernandez R, "The origin of the pozzolanic activity of calcined clay minerals : A comparison betweenkaolinite, illite and montmorillonite" 41 (41): 113-122, 2011

3 Liu KN, "Study on the mechanical properties and microstructure of fiber reinforced metakaolin-based recycled aggregate concrete" 294 : 2021

4 Song XY, "Study on structural characteristic and mechanical property of coal gangue in activation process" 32 : 358-363, 2004

5 "Standard for test methods of long-term performance and durability of ordinary concrete. GB/T 50082-2009" Chinese Standard Press 2009

6 "Standard for test methods of concrete physical and mechanical properties. GB/T 50081-2019" Chinese Standard Press 2019

7 "Standard for test method of performance on ordinary fresh concrete. GB/T 50080-2016" Chinese Standard Press 2016

8 "Specification for mix proportion design of ordinaryconcrete. JGJ/T 55-2011" Chinese Standard Press 2011

9 Zhang YL, "Reactivity activation of waste coal gangue and its impact on the properties of cement-based materials – A review" 234 : 2020

10 Guan X, "Performance of microwave-activated coal gangue powder as auxiliary cementitious material" 14 : 2799-2811, 2021