| Due to the special environmental characteristics and seasonal differences,the pavement in seasonal frozen area is obviously inadequate to resist the influence of natural factors,and the diseases such as frost heave,frost boiling,thaw settlement and cracks are serious.The maintenance of pavement in seasonal frozen area is facing great difficulties,and the early-built expressway has entered the stage of large and medium-sized repairs.At present,the new technology of polymer grouting is only applied in the field of highway in non-seasonal frozen areas,but the application of highway in seasonal frozen areas has not yet been carried out.Therefore,studying the mechanical properties of polymer grouting materials in seasonal frozen zone is the foundation and key of polymer grouting technology applied in pavement maintenance in seasonal frozen zone,and it is of great significance to popularize the application of polymer grouting technology in seasonal frozen zone.The polymer grouting technology based on polymer grouting material has a direct impact on the grouting effect.Combining with the maintenance plan of Jilin Province highway maintenance management department,the effects of temperature change and freeze-thaw cycle on the mechanical properties of polymer grouting material in seasonal freezing zone are studied.The main research contents and achievements are as follows:(1)The compressive strength and tensile strength of polymer grouting materials with different densities at different temperatures ranging from-35℃~40℃.The results show that the compressive strength and tensile strength increase with the increase of density,and the change of temperature has a certain influence on the compressive strength.When the density is high,the influence of temperature on the compressive strength is obvious,and the compressive strength decreases with the increase of temperature;Temperature has little effect on the tensile strength of polymer materials,and the tensile strength increases with the increase of density.(2)The effects of freeze-thaw cycles on the mechanical properties of polymer grouting materials with different densities were analyzed through freeze-thaw cycles of different times.It is found that the mechanical properties decrease with the increase of freeze-thaw cycles,and the effect of freeze-thaw cycles on 0.4g/cm~3 material is the smallest.It provides theoretical support for selecting suitable polymer grouting materials in engineering practice in seasonal freezing zone.(3)After repairing the pavement of the test section with polymer grouting,comparing the results of FWD and GPR before and after grouting,it is found that the deflection of the test section decreases by 20%,the loose parts are filled and compacted.Polymer grouting material can be used to repair pavement diseases in seasonal frozen area,effectively treat pavement diseases in seasonal frozen area and improve pavement strength. |
