水工混凝土的超疏水仿生构建及微观机理

Superhydrophobic Biomimetic Construction and Microscopic Mechanism of Hydraulic Concrete

将有机异辛基三乙氧基硅烷(TS)与无机纳米二氧化硅复合,通过“二元协同”仿生方法,制备了整体超疏水水工混凝土,探究了TS掺量和养护条件对混凝土力学性能和疏水性能的影响,并采用扫描电子显微镜(SEM)、X射线衍射(XRD)、红外光谱(FT-IR)分析了材料的微观形貌、物相组成和疏水改性机理。结果表明,养护条件对混凝土疏水性影响较大,在自然养护条件下,当TS掺量达到3%(质量分数)后,混凝土均呈现出超疏水状态,最大接触角为155.6°。纳米粒子的掺入促进了水泥水化,提升了试件的抗压强度。改性后的水工混凝土具有良好的疏水性,288 h浸水吸水率下降了68.8%。

The organic isooctyltriethoxysilane(TS)and inorganic nanosilicon dioxide(nano-SiO_(2))were combined to prepare monolithic superhydrophobic hydraulic concrete by"binary synergistic"biomimetic method,and the effects of TS dosage and curing conditions on the mechanical properties and hydrophobicity properties of concrete were investigated.The microscopic morphology,phase composition and hydrophobic modification mechanism of materials were analyzed by scanning electron microscopy(SEM),X-ray diffraction(XRD)and fourier transform infrared spectrometer(FT-IR).The results show that the curing conditions have a large influence on the hydrophobicity of concrete.Under natural curing conditions,when TS dosage reaches 3%(mass fraction),the concrete all exhibits superhydrophobicity,with a maximum contact angle of 155.6°.The incorporation of nanoparticles promotes cement hydration and enhances compressive strength of specimens.The modified hydraulic concrete has good hydrophobicity,and the water absorption rate decreases by 68.8%in 288 h immersion.