Research On Construction Of Semi-rigid Base Based On Seasonal Tenperature

Semi-rigid base is widely applied in China’s highway construction. Security of its structure directly affects the life of the road. During the construction of semi-rigid base, due to the different seasons cause curing temperature is too high or too low can easily result in insufficient strength of the base material. Flexural fracture of layer bottom of Grassroots because of greater tensile stress may cause cracking of the surface layer structure.In the study we compare the traditional construction methods and continuous paving construction methods, analysis the vehicle load influence on the mechanical characteristic of the pavement structure, under different temperature conditions during the formation stage of pavement structure, by the experimental research of system and mechanical response. The research provides the basis for the development of traffic control measures in the semi-rigid asphalt, during the formation period of pavement strength.It provides the basis for the selection of construction methods in different curing temperatures.(1) We proceed some system investigations of climatic feature in some regions in Heibei province, semi- rigid base pavement structure construction and construction vehicle loads, such that determine the typical semi-rigid asphalt pavement structure,material ratio and load distribution of Heibei province. We also determine the the curing temperature for calculating, according the survey and temperature prediction model.(2) According to the laboratory test findings, we studied the road variation of performance with age, under the different temperatures regimen(10 ℃, 20 ℃, 30 ℃) condition, and with the different mix of Semi- rigid base material such as limestone soil, cement stabilized gravel, flyash stabilized macadam.(3) We selected two typical Semi- rigid base pavement structures, with the usage of finite element software ANSYS proceed quantitative analysis of grassroots mechanical deformation, by stages, layered construction and construction method of continuous paving respectively, under the circumstances that axial load of 180 KN during the grassroots construction process. The results shows: by the usage of traditional construction methods, splitting strength does not meet the mechanical requirements; while using the continuous paving construction method, when the curing temperature is 10 ℃, it meets the strength requirements if curing time is 14 days and control the load; when the curing temperature is 20 ℃, it meets the strength requirements if control the load; when the curing temperature is 30 ℃, it meets the strength requirements if control the load under the curing time of 7d and it meets the strength requirements under the curing time of 14 d.(4) Establish the regression equation between maximum tensile stress of layer bottom and age and axle load, which provides the basis for the control of the health age of the construction and vehicle axle load.