水泥基材料多尺度抗裂增韧机理研究进展

Cement-based materials have a multi-phase and multi-scale structure, and each component forming the structure affects the overall toughness to varying degrees. This review summarized the cracking-resistance and toughening mechanisms of relevant components classified in macroscale, mesoscale and nanoscale to cement-based materials. In the macroscale (such as the cementitious component, aggregate, admixture, fiber, water-binder ratio, curing system, etc.), the influence mechanisms of the physicochemical effects of relevant components on the cracking resistance and toughening characteristics of cement-based materials were analyzed. In the mesoscale (such as microsphere, whisker, capillary crystalline material, etc.), the enhancement effects such as volcanic ash, filling, bridging, bonding, capillary crystallization were described. In the nanoscale (such as nano-SiO₂, nano-CaCO₃, graphene, carbon nanotube, microorganism, nano-polymer, etc.), the mechanisms enhancing and optimizing the microstructure of hydration products, growth mode, and pore structure of hardened paste were introduced. The conjugating toughening effects of cross-scale components such as ‘carbon fiber+carbon nanotubes’, ‘fiber+whisker+graphene’ were elucidated. In addition, the shortcomings in the current application/research, and the future development trends for toughening components in different scales were also discussed.