消泡剂种类及掺量对海砂超高性能混凝土(UHPC)性能的影响

Effects of Defoaming Agents and Dosage on Performance of UHPC with Sea Sand

对比研究了消泡剂种类及掺量对海砂UHPC流动度、密度、含气量、强度与吸水率的影响规律,并通过图像处理分析技术探究了消泡剂对海砂UHPC气泡总量、平均孔径及孔径分布的影响。结果表明,在一定掺量范围内,有机硅类消泡剂及聚醚消泡剂的掺入可提升海砂UHPC的流动度、抗压强度,降低含气量,降低密度,但掺有机硅类消泡剂的海砂UHPC的吸水率先降低后增加,掺聚醚类消泡剂的海砂UHPC的吸水率则不断降低;相对而言,掺用聚醚类消泡剂可使海砂UHPC在较低的消泡剂掺量下获得更优良的性能。图像处理分析结果表明,掺聚醚消泡剂的海砂UHPC气泡总量更低,平均孔径更小,气泡孔径分布也更合理。

Influence of different dosage and different defoaming agents on the fluidity,density,air content,comprehensive strength and the absorption of water on UHPC with sea sand were studied,and total porosity,average pore size and distribution of pore size for the UHPC with sea sand was investigated through image processing and analysis technology.Results show that fluidity and compressive strength increase and air content and density decrease with the addition of defoaming agent in certain dosage ranges of organic silicon defoaming agent and polyether defoaming agent.The absorption of water increases after first decreases with addition of organic silicon defoaming agent,while the absorption of water reduces constantly with addition of polyether defoaming agent.By comparison,the UHPC with sea sand can give a better performance with a lower addition of organic silicon defoaming agent.Image processing analysis show that UHPC with sea sand can have a less total porosity,a smaller average pore size,and a more reasonable distribution of pore size with the of organic silicon defoaming agent.