Experimental Study On Insulation Effect And Mechanical Properties Of Cold Resistance Layer Of Subgrade In Seasonal Frozen Area

Seasonal frozen soil is a kind of permafrost that freeze in winter and melt insummer. Seasonal frozen soil is special that influence the performance and life of roadbadly. It makes road performance degenerate faster and makes road life shorter. Themain phenomenon of road frost damage of seasonal frozen area are frost heave andfrothing. The common road frost damage governance measures are improvingfoundation soil and improving the anti-frost heaving characters of road buildingmaterials. Lack of systematic research on road frost damage mechanism. It does nothave targeted governance norms and standards about concrete frost damagephenomenon characteristic. Therefore, research on freeze injury prevention measuresof seasonally frozen District road could extend the road life and extend roadmaintenance cycle reduce maintenance costs. It could bring considerable economicand social benefits and provide protection for the steady development of the nationaleconomy.In this paper, on the basis of analyzing frost damage mechanism and formcharacteristics of seasonal frost area. By setting cold resistance layer in the subgradeto barrier surface negative temperature passed down and insulate subgrade. By thisway it could prevent road frost damage of seasonal frost region. Cold resistance layeris composed of rubber particles and fly ash soil material. It has good freeze-thawresistance character and high strength and low cost and environmentally friendly.Experiment on cold resistance layer material to research the mechanical propertiesand the thermal insulation effect. By using the roadbed material mechanicalparameters test machine under freeze-thaw cycles to obtain the mechanical parametersof cold resistance layer under dynamic load and freeze-thaw cycles in order toevaluate the mechanical properties of cold resistance layer. Through the winteroutdoor low temperature test to study insulation properties of cold resistance layer. Using real test conditions of seasonal frozen area to get actual performanceparameters of materials and improve the reliability of analysis and evaluation. In thispaper, through the two-part test, the following conclusions were obtained:1.Analyze the effect to mechanics parameters of the cold resistive material rubberparticles modified fly ash soil under combined effects of freeze-thaw cycles anddynamic load frequency and temperature variations. With the increase of freezing andthawing views the stress and strain of cold resistive material have increased and themodulus is stable. With the increase of dynamic load frequency the stress and strainand modulus of cold resistive material have decreased.2.The insulation effect of cold resistive material rubber particles modified fly ashsoil is obvious. It could reduce frost heave of subgrade soil under negativetemperature.