石膏对预应力孔道压浆料性能的影响

Effect of gypsum on the properties of pre-stressed duct grouting material

预应力孔道压浆料的质量对于公路桥梁的安全至关重要。试验通过用石膏等量替代矿物掺合料,借助于XRD测试压浆料水化产物的变化,研究了石膏对压浆料流动性、抗折强度、抗压强度和收缩率的影响。采用SEM测试压浆料微观形貌变化。结果表明,石膏可以大幅度促进水化反应,使得钙矾石的量由少变多,内部结果更加致密,同时会在后期生成硅灰石膏,可以有效避免压浆料后期强度的倒缩现象,从而有效提高压浆料的物理性能。

The quality of prestressed concrete grouting is very important for the safety of highway bridges.The influence of gypsum on the fluidity,flexural strength,compressive strength and shrinkage of the cement paste was studied by replacing mineral admixture with gypsum and by means of XRD test.The morphology of the compacted slurry was measured by SEM.The results show that gypsum can greatly promote hydration reaction,so that the amount of tringite changes from less to more,and the internal results are more compact.At the same time,wollastonite will be formed in the later stage,which can effectively avoid the backward phenomenon of the late strength of the grouting material and effectively improve the physical properties of the grouting material.