Experimental study on corrosion resistance of concrete mixed with ceramic powder and fly ash

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Date
2023-08-15
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Saudi Digital Library
Abstract
At present, whether in life or production, the production of ceramics is easy to produce a lot of ceramic waste, it is difficult to deal with ceramic waste. At present, it is difficult to recycle and reuse by burying in the soil. There are a large number of waste ceramics directly placed around the city, which is easy to affect the beauty of the city, and cause the waste of ceramic resources. Ceramic is easy to fracture, and has a certain availability. The demand of concrete is very big in our country, especially in recent years, the demand of cement reaches its peak. Therefore, the further harmless treatment and resource utilization of ceramic waste is still an urgent problem to be solved.The form effect and aggregate effect of fly ash, small surface area, and the reaction between fly ash and highly efficient water reducing agent can reduce the use of water consumption and water-binder ratio, thus improving the strength and durability of concrete. Therefore, it is more appropriate to replace cement with ceramic powder and fly ash in concrete. The research content of this paper mainly includes (1) ceramic grinding, the study of ceramic particle composition, the best ceramic ball milling process and the strength characteristics of ceramic powder (2) through different dosage of ceramic powder and fly ash (ratio of 3: 7) The erosion appearance observation, mass change rate and corrosion resistance coefficient of the reclaimed cement mortar specimen were tested to study the corrosion resistance of the ceramic - fly ash reclaimed concrete. (3) The transport and crystallization process of salt solution in the reclaimed concrete of ceramic fly ash were studied to reveal the corrosion resistance mechanism of the reclaimed concrete of ceramic fly ash. The main research conclusions of this paper are as follows: (1) Firstly, the ceramic block is physically crushed into ceramic particles, and then the ceramic particles are ground into ceramic micro-powder. The optimum process performance is obtained when the speed is 350r/min and the time is 45min. At this time, the specific surface area of the ceramic powder prepared is 7000~8000 cm2/g. The ceramic powder and fly ash (the ratio is 3: 7) Substituted part of cement was mixed into mortar specimens to prepare ceramic powder and fly ash regenerated cement mortar specimens. The strength test of cement mortar was carried out, and the conclusion was drawn that the strength activity was greater than 56% when 30% of ceramic powder and fly ash (ratio of 3:7) were mixed into the same amount of substitute cement without other mineral materials. (2) This study proposed a method to partially replace cement with ceramic powder and fly ash (the ratio is 3:7) to improve the sulfate resistance of concrete, and mixed with 0%, 10%, 20%, 30% ceramic powder and fly ash (the ratio is 3: 7) After 28 days of standard curing, the cement mortar specimen was half-soaked in 5% sodium sulfate solution. With the passage of half-soaking time in sodium sulfate solution, the mass loss rate of the reclaimed cement mortar gradually decreased with the increase of ceramic powder and fly ash content, and the corrosion resistance coefficient of the reclaimed cement mortar first increased and then decreased. Under the condition of constant water-binder ratio, the change of the content of ceramic powder and fly ash has a great influence on the salt crystallization erosion resistance of mortar. The corrosion resistance coefficient of the reclaimed cement mortar group with high content is higher than that of the reclaimed cement mortar group with low content of ceramic powder and fly ash. The reclaimed cement-based material mixed with ceramic powder and fly ash in semi-immersed sodium chloride solution has a higher ability of binding chloride ions. With the passing of curing time of reclaimed cement mortar, the binding chloride ion performance of reclaimed cement-based material decreases. (3) Through the capillary rise and crystallization experiment and capillary water absorption experiment, it is concluded that with the increase of the content of ceramic powder and fly ash, the total porosity, coarse capillary porosity and fine capillary porosity of recycled concrete all decrease with the increase of the content of ceramic powder and fly ash: The capillary rise height and osmotic crystallization rate are linearly related to the capillary porosity, but not linearly independent of the capillary porosity. Therefore, the capillary porosity plays a key role in the capillary transport, migration and crystallization process of sulfate solution in ceramic powder and fly ash recycled concrete. This topic has carried out a large number of experimental studies on the strength characteristics and anti-erosion applications of ceramic powder and fly ash. Firstly, the strength activity of ceramic powder and fly ash into ceramic powder by the grinding process of ceramic particles is studied. Then, the strength change law of the reclaimed mortar specimen of ceramic powder and fly ash under the semi-immersion of salt solution is studied under different mixing quantities. Finally, the anti-erosion mechanism of ceramic powder and fly ash regenerated concrete was obtained through the transport of salt solution in ceramic powder and fly ash regenerated concrete and crystallization process experiment, which proved that ceramic powder and fly ash regenerated micro powder have certain activity, and verified that ceramic powder and fly ash can improve the anti-erosion performance of concrete
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Keywords
Ceramic powder and fly ash, Recycled concrete, Sulfate crystallization, Transportation, Corrosion resistance
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