消泡剂与花岗岩石粉掺量对高性能混凝土性能的影响

Effect of Defoamer and Granite Powder on Performance of High Performance Concrete

聚醚改性有机硅消泡剂、花岗岩石粉的掺量会对超高性能混凝土(UHPC)的物理性能、收缩性能、抗压强度产生影响。研究进行试验测试,并通过超景深显微镜对UHPC气泡总量、平均孔径及孔径分布进行观察分析。结果表明,水胶比固定花岗岩石粉一定掺量范围内促进UHPC孔隙细化,石粉滚珠润滑作用提升UHPC的物理和易性能、降低含气量、提高密度、改善早期自收缩性能、抗压强度未降低;优化花岗岩石粉掺入量后,调控聚醚改性有机硅消泡剂掺入促使花岗岩石粉UHPC中泡沫破裂,UHPC颗粒堆积更为紧密、密度提高、结构紧密、气泡总量降低、平均孔径更小及孔径分布也更合理。

The content of polyether modified organosilicon defoamer and granite powder will affect the physical properties,shrinkage properties and compressive strength of ultra-high performance concrete(UHPC).The total number of bubbles,average pore size and pore size distribution of UHPC were observed and analyzed by ultra-depth microscope.The results show that the water-cement ratio can promote the pore refinement of UHPC in a certain range of fixed granite powder,and the ball lubrication of stone powder can improve the physical and workability of UHPC,reduce the air content,increase the density,improve the early self-shrinkage performance,and the compressive strength is not reduced.After optimizing the amount of granite powder,adjust the addition of polyether modified silicone defoamer to cause the foam in granite powder UHPC to burst,and the particles in UHPC will pile more closely.The density is increased,the structure is compact,the total number of bubbles is reduced,the average pore size is smaller and the pore size distribution is more reasonable.