侵蚀抑制材料对高速铁路无砟轨道现浇混凝土抗冻融性能影响及作用机制

Effect and Mechanism of Erosion Inhibition Materials on Freeze-thaw Resistance of Cast-in-place Concrete in Ballastless Track of High Speed Railway

针对北方地区无砟轨道现浇混凝土冻融破坏问题,对比了不同掺量侵蚀抑制材料对混凝土抗冻性能的影响,同时对无砟轨道现浇混凝土抗冻提升机制进行了分析。结果表明:侵蚀抑制材料改善了无砟轨道现浇混凝土的疏水性能,降低了混凝土吸水率,提升了混凝土抗冻性能;当侵蚀抑制材料掺量为20 kg/m3时,侵蚀抑制材料对无砟轨道现浇混凝土的抗冻性能提升效果最为显著,混凝土盐冻剥落质量可以降低52.7%;当侵蚀抑制材料掺量为40 kg/m3时对混凝土抗冻性能具有一定的负面作用。侵蚀抑制材料可以影响无砟轨道现浇混凝土内气泡的分布和大小,进而影响无砟轨道混凝土抗冻融性能。

In order to solve the problem of frost-thaw damage of cast-in-place concrete for ballastless track in northern China,the influence of different dosage of corrosion inhibiting materials on frost resistance of concrete was compared,and the frost resistance improvement mechanism of cast-in-place concrete for ballastless track was analyzed.The results show that the corrosion inhibiting materials can improve the hydrophobic property of the cast-in-place concrete for ballastless track,reduce the water absorption of concrete,and improve the frost resistance of concrete.When the content of corrosion inhibiting material is 20 kg/m~3,the frost resistance of cast-in-place concrete for ballastless track is improved most significantly,and the frost spalling mass of concrete can be reduced by 52.7%.When the content of corrosion inhibiting material is 40 kg/m~3,it has a certain negative effect on the frost resistance of concrete.Corrosion inhibiting materials can affect the distribution and size of air bubbles in the cast-in-place concrete of ballastless track,and then affect its freeze-thaw resistance.