Enhancement mechanical performance of brick powder-cement mortar with bio-inspired material.

As building solid waste, the replacement of brick powder for cement is conducive to reducing energy consumption and costs of building material. However, the low reactivity of BP cannot be ignored, as it negatively impacts the performance of mortar. To address this issue, this study incorporates a mixture of plant-based TA (Tannic) with BP into a pre-mixed paste and adds it to cement mortar. The porous structure of the BP facilitates the adhesion and complexation of polyphenol hydroxyl groups, enhancing the dispersion of BP in the cement paste. Moreover, the in-situ formation of nano-sized calcium-based complexes, as evidenced by AFM, XRD, TGA and SEM tests, provide excellent nucleation sites, which regulate cement hydration and enhance the mechanical properties of BP-cement mortar, significantly reducing the proportion of capillary pores and large pores in the mortar. By substituting 15% of cement with TA-modified BP, the compressive strength and flexural strength increased by 49.19% and 5.72%, respectively, and the shrinkage rate was reduced by 73.15%. Thus, this simple and green modification method will provide more inspiration for the efficient utilization of BP in cement-based materials. • The paper will provide more inspiration for the efficient utilization of BP in cement mortar. • The plant-based TA is attached to the surface of BP through complexation-adsorption. • TA-modification improve the dispersibility of BP-cement paste. • TA-modified BP mortar obtained higher strength and lower shrinkage, compared to untreated BP mortar. NOTE: BP mean brick powder. TA mean Tannin acid. [ABSTRACT FROM AUTHOR]