###### Abstract  
Using industrial byproducts to replace cement is an important way to reduce carbon emissions from the cement industry. In this study, the effects of two industrial byproducts, fly ash (FA) and quartz powder (QZ), as supplementary cementitious materials (SCMs) on the macroscopic properties and microstructure of cement-based materials were experimentally investigated. The results of the compressive strength and ultrasonic pulse velocity experiments showed that QZ significantly mitigated the decrease in strength and ultrasonic pulse velocity caused by the reduction in cement dosage in the early stage. Moreover, the 28-day compressive strength of the FA group was comparable to that of the control group, and regression analysis indicated a negligible effect of FA addition on 28-day compressive strength. X-ray diffraction and Fourier transform infrared spectroscopy experiments showed that QZ can promote the hydration reaction in the early stage. Scanning electron microscopy images revealed that a layer of hydration products can form on the surface of FA after 28 days of hydration. Hydration heat experiments indicated that FA significantly reduces the release of hydration heat, while QZ promotes the formation of ettrinigite through nucleation effects in the early stage of hydration, thereby accelerating the release of hydration heat. Thermogravimetric analysis after 28 days showed that the amount of hydration products and calcium hydroxide produced decreased with the addition of cementitious materials. Finally, the use of FA and QZ was analyzed for carbon emissions and energy consumption. The results showed that using these two cementitious materials significantly reduces carbon dioxide emissions and energy consumption. of cement products with high mechanical properties and good durability indices [9; 12; 13; 14]. These SCMs can serve as pozzolanic materials or fillers, among other roles [15]. Pozzolanic materials, such as fly ash (FA), undergo a pozzolanic reaction with calcium hydroxide (CH) produced during cement hydration [16], generating additional calcium silicate hydrate (C-S-H) and other hydration products [15; 17]. The additional C-S-H fills pores by promoting pore refinement and cementitious matrix thickening. Non-pozzolanic, high-fineness inorganic materials like quartz powder (QZ) create a filler effect. They directly fill small pores in the cement slurry and, through physical action, promote early cement hydration, densifying the cementitious matrix [18; 19]. They also provide nucleation and growth sites for hydration products [20; 21]. FA is one of the residues produced by coal-fired power generation and heating and is captured by electrostatic precipitators or bag filters before flue gas emission. The widespread use of FA in cement and concrete primarily depends on its fineness, chemical composition, phase composition, and pozzolanic activity. Meanwhile, QZ is a processing byproduct of quartzite [22], with its main crystalline component being silicon dioxide (SiO\({}_{2}\)). QZ is widely used in the building materials industry. It can be used as a filling material, a strength-enhancing material, and a raw material that improves the strength, wear resistance, and durability of cement and concrete during manufacturing [23]. Research on the mechanisms of FA and QZ in cementitious materials is extensive. For example, [PERSON] et al. compared the effects of QZ and metakaolin in geopolymers. They found that replacing fine aggregates with metakaolin increased strength by 86%, while QZ replacement resulted in a 42% increase. This indicates that different SCMs have varying effects on cementitious material properties [24]. [PERSON] et al. studied the application of QZ in carbonation curing, revealing that small-sized QZ particles exhibit beneficial effects on cement hydration and macroscopic properties, while larger QZ particles promote carbonation curing. This work confirms QZ's potential to enhance CO\({}_{2}\) capture in cement-based materials [22]. [PERSON] et al.