Enhancing cement-based composites via regulated hydration and concurrent construction of robust organic-inorganic network

Cement-based materials with excellent mechanical properties are in high demand in the civil engineering. This work utilized an innovative in-situ copolymerization approach for synergistic modification of cement-based materials. Vinyl hybrid silica microspheres (VSM) were synthesized through the sol-gel method. Subsequently, With the assistance of initiators and cross-linking agents, the VSM and acrylamide (AM) in-situ copolymerization and were uniformly dispersed in the cement matrix, leading to the successful development of a modified cement-based material. The copolymerization of VSM and AM resulted in the creation of a comprehensive three-dimensional hybrid network structure, interconnected by covalent bonds between the constituent components. Experimental results unequivocally demonstrate that the mechanical properties of the composite have undergone remarkable enhancement. Notably, the flexural strength experienced a substantial increase due to the in-situ polymerization of AM. Furthermore, the compressive strength was significantly improved, achieving a 21.4 % increase compared to samples modified with 2 wt% AM alone. The enhancement can be attributed to the synergistic effect of the in-situ copolymerization structure and the VSM attached to it. The microspheres not only aided in the development of a robust cement matrix and a higher compactness, but also bolstered the compressive modulus of the flexible polymer chains. Collectively, these factors contributed to an increase in the overall resistance to deformation, comprehensively enhancing the mechanical performance of the material. This study addresses the challenges posed by the loss of compressive strength during in-situ polymerization modification, introduces an innovative methodology aimed at significantly enhancing the mechanical properties of cement-based materials.