钢纤维对SAP内养护混凝土动态压缩和弯曲性能的影响

打开文本图片集

中图分类号：TU528 文献标志码：A文章编号：1000-4939（2025）03-0609-11

Abstract：In order to study the effect of steel fiber on the mechanical properties of internal curing concrete，super absorbent polymer （SAP）was used as the internal curing material，and dynamic compressive and four-point bending tests were carried out on normal concrete（NC），internal curing concrete（ICC）， and steel fiber internal cured concrete（SFRICC）.Pore structure and microstructural features analysis was made using nuclear magnetic resonance（NMR）and scanning electron microscope（SEM） to reveal the mechanism of SAP and steel fibers’ efect on the mechanical properties of concrete.The results show that the residual strength of SFRICC increases with the increase of steel fiber content.Steel fiber significantly reduces the weakening efect of SAP on the mechanical properties of concrete.The mechanical properties of SFRICC increase first and then decrease with the increase of steel fiber content.In addition，the mechanical properties of SFRICC are enhanced best when the volume content of steel fiber is 1.5% . The mechanical properties of concrete show an obvious strain rate efect.At high strain rates，the steel fiber content is negatively correlated with the dynamic increase factor（DIF）of SFRICC.SAP not only promotes cement hydration reaction，but also increases concrete porosity and pore size and reduces the effective area of concrete structural surface.And the steel fiber bridges the cracks on both sides of the fiber，which enhances the integrity of concrete and makes up for the damage of SAP to the internal structure of concrete. The two materials can play a good coupling role.

Key words：concrete； steel fiber； SAP；mechanical property；microscopic mechanism

混凝土因抗压强度高、耐久性好、可加工性高、原料易获取等优点成为水利、土木、道路、桥梁等工程的主要建筑材料之一。（剩余18339字）