Experimental Study On Fatigue Properties Of Low Exothermic Polymer Grouting Materials

With the rapid development of China’s economy,the construction of highway,railway and other transportation infrastructure in remote frozen soil areas is also increasing.In recent years,with the global climate warming,the foundation conditions in frozen soil areas are more severe,and the damage degree of frozen soil subgrade and pavement is aggravated.High polymer grouting technology is an important means of road disease repair and maintenance.However,in the face of special engineering environment in frozen soil area,traditional polymer grouting materials can no longer meet the demand.Low exothermic polymer grouting materials play an irreplaceable role in the repair and maintenance of road diseases in frozen soil area,but their performance in frequent loading is unknown.Based on the above background,this paper studies the fatigue properties of low exothermic polymer grouting materials used in road disease repair in frozen soil area by indoor test,The fatigue life of low exothermic polymer grouting materials is estimated,and the factors affecting the fatigue properties and microstructure of low exothermic polymer grouting materials are analyzed.The purpose of this paper is to provide theoretical basis and reference for the application of low exothermic polymer grouting materials in frozen soil.The main research contents and results are as follows :(1)the compressive properties of low exothermic polyurethane polymer grouting materials and the fatigue properties under compressive loading are studied,It includes the relationship of stress and strain,the relationship of strain cycle times of low exothermic polymer specimens with different density under the same stress level compressive loading,and the relationship of strain cycle times of low exothermic polymer specimens with the same density under different stress level compressive loading.(2)The anti-bending properties of low-heat polyurethane polymer grouting materials and fatigue properties under bending conditions were studied,including the load-displacement relationship during bending,the displacement cycle times of low-heat polymer specimens with different densities in the same stress level cycle,and the displacement cycle times of low-heat polymer specimens with the same density in different stress level cycle.(3)From the macroscopic fatigue test phenomenon,the fatigue failure forms of low exothermic polyurethane polymer grouting materials under compression and bending are analyzed and summarized.