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Fair-faced concrete (FFC) with a mirror effect was successfully prepared. The grey value standard deviation, porosity, crack rate and glossiness of the concrete surface were used to characterise the apparent quality of the FFC. The effect of polycarboxylate superplasticiser (PSP) and polyacrylamide (PAM) viscosity-modifying admixture on the mirror effect of the FFC was investigated. Changes in the hydration products and microstructure of the FFC were monitored by means of X-ray diffraction, thermogravimetric analysis, scanning electron microscopy and mercury intrusion porosity, and the potential mechanism was analysed. The results indicate that PAM reduced the number and size of calcium hydroxide (Ca(OH)2) crystals and changed the morphology of these crystals from a large-size parallel stacking state to a small-size edge eroded structure. PAM also refined the pore size of the concrete; the most probable pore size at the optimum dosage level was 13.73 nm, which was much lower than that at other PAM dosage levels. The use of PSP introduced air, which had an adverse effect on the concrete surface. However, PSP can also improve the flowability of concrete and make it easier for bubbles to discharge. The combined action of PSP and PAM provided a better mirror effect for the FFC. [ABSTRACT FROM AUTHOR]

The effects of dried tea residues on the nutritional parameters and fermentation quality, microbial community, and in vitro digestibility of alfalfa silage were investigated. In this study, dried tea residues generated from five different processing techniques (green tea, G; black tea, B; white tea, W; Pu'er raw tea, Z; Pu'er ripe tea, D) were added at two addition levels (5% and 10% fresh weight (FW)) to alfalfa and fermented for 90 days. The results showed that the tea residues increased the crude protein (CP) content (Z10: 23.85%), true protein nitrogen (TPN) content, DPPH, and ABST radical scavenging capacity, total antioxidant capacity (T-AOC), and in vitro dry matter digestibility (IVDMD) of the alfalfa silage. Moreover, the pH, ammonia-N (NH3-N) content, and acetic acid (AA) content decreased (p < 0.05). The effects of tea residues were promoted on these indicators with increasing tea residue addition. In addition, this study revealed that the influence of dried tea residues on the nutritional quality of alfalfa silage was greater than that on fermentation quality. Based on the nutrient composition, the addition of B or G to alfalfa silage can improve its silage quality, and these tea byproducts have the potential to be used as silage additives. [ABSTRACT FROM AUTHOR]

Dry tea residue is a byproduct generated during the production, processing, and storage of tea leaves. The active ingredients and microbial composition of dried tea residue vary depending on different tea processing techniques. This study investigated the effects of six processed dry tea residues-green tea (G), black tea (B), raw Pu'er tea (Z), white tea (W), and ripe Pu'er tea (D)-at two addition ratios (5% and 10%) on the nutritional composition, fermentation quality, in vitro fermentation, and bacterial community of sweet sorghum ( Sorghum bicolor ) in the ensiling process. Compared to the control group (CK), the addition of tea residue significantly increased the crude protein (CP) content in silage by 17.9% to 180% ( p < 0.05), and the content increased with increasing ratios of tea residue. The G10 treatment resulted in the highest CP content, reaching 16.4%. Including tea residue also influenced the ratio of ammonia nitrogen (NH 3 -N) to non-protein nitrogen (NPN). Furthermore, the G and Z treatments at both addition levels increased the total phenolic content, DPPH free-radical scavenging activity, and total antioxidant capacity of the sweet sorghum silage. Except for the Z5 and W10 treatments, the addition of tea residue did not significantly affect in vitro dry matter digestibility. Overall, this study showed that incorporating tea residue could enhance the nutritional quality and antioxidant capacity of sweet sorghum silage, and the G5 treatment performed the best. The research results suggested that dried tea residues have potential as silage additives.