Experimental Research On Corrosion Resistance Of Mortar Bolt Anchorage Body

In view of the durability of anchor structure,this thesis focuses on the compressive properties,bonding properties,corrosion properties and microstructure of mortar bolt anchorage body.The macroscopic mechanical properties and microstructure morphology of anchorage body are obtained by using the indoor accelerated corrosion test method.The corrosion resistance of anchorage body is revealed.(1)This thesis observes that the cylinder sample with high concentration of solution corrosion will appear network cracks on the bottom and side through long-term immersion test.The uniaxial compressive strength test of cement mortar under the influence of different concentration,different ions and different water-cement ratio was carried out.It was found that the increase of sodium sulfate solution concentration and water-cement ratio accelerated the decline speed of cement mortar compressive strength.The addition of chloride ion improves its corrosion resistance.(2)The bond strength variation rule of the interface between bolt and mortar is obtained through the bond strength test,and it is found that the corrosion resistance coefficient of bond strength is greater than that of compressive strength.According to the strength fitting formula,and combined with the influence of concentration of corrosive solution and temperature on the acceleration coefficient,the strength variation formula of mortar anchorage body under low concentration solution corrosion was deduced.(3)The crack connecting on the surface of the anchorage body causes the mortar to flake off through the high temperature solution cycle and soak drying cycle,and the invading ions and hydration products fill in the crack,which leads to the expansion of the anchorage body and accelerates the mortar to fall off.It was found that the p H of the composite solution was lower than that of the sulfate solution after the corrosion of anchorage body.(4)The microstructures obtained by thin section observation and scanning electron microscope(SEM)revealed the development law of cracks and pores,and clarified the mechanism of corrosion resistance degradation of mortar bolt anchorage body.