Quartz powder is a byproduct of quartzite processing. To date, research on the use of quartz powder in carbonation curing is extremely limited, and the carbonation curing mechanism of concrete containing quartz powder is still unclear. In this study, we focused on the effects of fineness and content of the quartz powder on carbonation curing for cement-quartz powder binary mixtures and compared the results with those from sealed curing to clarify the effects of the quartz powder under carbonation curing and sealed conditions. The quartz powder's action is primarily influenced by nucleation and dilution effects, altering the coupling of hydration and carbonation, thereby influencing carbonation curing outcomes. Experimental results reveal distinct mechanisms under sealed and carbonation curing. Under sealed curing conditions, the smaller particles of quartz-S5 (sample SC-Q10-S5) promoted cement hydration more effectively under the influence of nucleation, and the samples showed better compressive strengths, electrical resistivities, and ultrasonic pulse velocity gains when the quartz powder replaced 10 % of the cement. The introduction of larger quartz-S20 particles (sample CC-Q10-S20) promoted the carbonation reaction more significantly (Affected by the dilution effect, which promotes CO diffusion) and showed better compressive strength, electrical resistivity, and ultrasonic pulse velocity gain compared to the smaller particles of quartz-S5 during carbonation curing. In summary, adding quartz powder as a partial substitute for cement in the carbonation curing process standardized the carbonation curing, and under the coupling of hydration and carbonation reactions, larger particles are more beneficial for enhancing carbonation curing properties compared to smaller particles.

中文翻译：

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石英粉细度和含量对碳化固化效率提高的机理


石英粉是石英岩加工的副产品。迄今为止，关于石英粉用于碳化养护的研究极其有限，含石英粉混凝土的碳化养护机理仍不清楚。在本研究中，我们重点研究了石英粉的细度和含量对水泥-石英粉二元混合物碳化养护的影响，并将结果与​​密封养护的结果进行了比较，以阐明石英粉在碳化养护和密封条件下的影响。石英粉的作用主要受到成核和稀释效应的影响，改变水合和碳酸化的耦合，从而影响碳酸化固化结果。实验结果揭示了密封和碳化固化下的不同机制。在密封养护条件下，较小颗粒的石英-S5（样品SC-Q10-S5）在成核作用的影响下更有效地促进水泥水化，并且样品表现出更好的抗压强度、电阻率和超声脉冲速度增益。粉末替代了 10% 的水泥。引入较大的石英-S20颗粒（样品CC-Q10-S20）更显着地促进碳酸化反应（受稀释效应影响，促进CO扩散），并与相比表现出更好的抗压强度、电阻率和超声脉冲速度增益碳化固化过程中石英-S5 的较小颗粒。 综上所述，在碳化养护过程中添加石英粉作为水泥的部分替代品，使碳化养护标准化，并且在水化和碳化反应的耦合下，较大的颗粒相对于较小的颗粒更有利于增强碳化养护性能。