再生风积沙骨料表面疏水改性方法与机制研究

Surface Hydrophobic Modification Methods and Mechanisms of Recycled Aeolian Sand Aggregates

摘要:

针对风积沙作为混凝土骨料使用时粒径小、比表面积大、吸水性强的问题，采用水泥胶结与表面疏水改性的方法，制备了大粒径表面疏水型再生风积沙骨料.结果表明：经硅烷偶联剂配合有机硅树脂改性的再生风积沙骨料，其吸水率明显降低，改性剂配比对再生风积沙骨料吸水率的影响较小；疏水改性不会降低再生风积沙骨料的强度以及再生风积沙骨料与水泥石间的黏结强度；使用表面改性再生风积沙骨料制备混凝土，其力学性能和工作性能明显改善；疏水改性可以优化再生风积沙骨料表面的微观结构，增大其表面浸润角.

Abstract:

To address the issue of small particle size， large specific surface area and high water absorption when aeolian sand was used as concrete aggregate， a large particle size surface hydrophobic recycled aeolian sand was prepared using cementation and surface hydrophobic modification. The results demonstrate that the water absorption of the recycled aeolian sand modified by a silane coupling agent with silicone resin is significantly reduced， and the modifier ratio has less influence on the water absorption of the recycled aeolian sand. Furthermore， hydrophobic modification does not reduce the strength of the recycled aeolian sand and the bond strength between recycled aeolian sand aggregate and cement stone. The mechanical properties and workability of concrete prepared with surface-modified recycled aeolian sand are significantly improved. The hydrophobic modification can optimize the surface microstructure of recycled aeolian sand and increase its surface contact angle.