纳米 $ SiO_{2} $ 稳泡效应及其对泡沫混凝土性能的影响

泡沫的稳定性是影响泡沫混凝土性能的重要因素, 文章利用硅烷偶联剂(烷氧基硅烷聚合物)对纳米$\mathrm{SiO}_{2}$（简称NS）进行表面润湿性改性, 研究改性纳米$\mathrm{SiO}_{2}$稳泡剂对泡沫稳定性的影响, 以及不同掺量改性纳米$\mathrm{SiO}_{2}$稳泡剂对泡沫混凝土流动性、强度、干燥收缩的影响。研究结果表明: 硅烷偶联剂能够有效地改变纳米$\mathrm{SiO}_{2}$表面润湿性, 只有适当润湿性和掺量的纳米$\mathrm{SiO}_{2}$才能起到提高泡沫稳定性的作用; 随着改性纳米$\mathrm{SiO}_{2}$稳泡剂掺量的增加, 泡沫混凝土的流动度会略有下降, 抗压强度得到明显提升, 而抗折强度受到的影响不大, 干燥收缩率也受到一定程度的抑制。

The stability of foam is the key factor affecting the performance of foamed concrete. In this experiment, the surface wettability of nano- $ SiO_{2} $ was modified by silane coupling agent (alkoxy silane polymer). On this basis, the influence of modified nano- $ SiO_{2} $ foam stabilizer on the stability of foam was studied. Furthermore, the effects of different amount of modified nano- $ SiO_{2} $ foam stabilizer on the fluidity, strength and drying shrinkage of the foamed concrete were studied. The results show that silane coupling agent can effectively change the surface wettability of nano- $ SiO_{2} $. Only nano- $ SiO_{2} $ with proper wettability and concentration can enhance the foam stability. With the increase of the content of modified nano- $ SiO_{2} $ foam stabilizer, the fluidity of foamed concrete will decrease slightly, the compressive strength will obviously increase, the flexural strength will not be greatly affected, and the drying shrinkage can also be restrained to a certain extent.