Study On Anti-cracking Technology Of Reinforced Semi-rigid Base Asphalt Highway With Basalt Fiber Ribbons In Freezing Areas Of Hebei Province

Semi-rigid base asphalt pavement is the most widely used structural form of high-grade highways in China.However,the problem of cracks on semi-rigid base asphalt pavements has not yet been solved.The existing literature shows that in the cold regions of northern China,there would be a lot of cracks on the surface of newly constructed asphalt road after a winter season.These cracks will not only shorten the service life of the roads and increase the cost of maintenance,but more importantly,threaten hidden dangers to people’s driving safety.For the cracking problem of semi-rigid base asphalt pavement,scholars at home and abroad have carried out a lot of research and achieved certain results.However,the problem of reflective cracking in semi-rigid base asphalt pavement has not yet been effectively solved.Therefore,the study on the anti-cracking of semi-rigid base asphalt pavement in cold regions is of great significance.Firstly,this paper conducts field investigation on road diseases in cold regions of Hebei Province.Through repeated observations of road cracks in the second phase of Zhangcheng Highway and the western suburbs of Kangbao County,semi-rigid base asphalt pavements in cold regions of Hebei Province can be identified.Through surveys it is known that main disease is temperature-type reflection cracks.Then based on the theory of heat transfer theory,the temperature field of the second phase of Zhangcheng Expressway in cold regions of Hebei Province was numerically simulated using ABAQUS finite element software,the 24 h temperature field of the asphalt pavement structure on represented day in the high temperature season and in the low temperature season is obtained.According to the measured temperature data of the pavement structure,the annual temperature change curve of the structural layers of the second phase of Zhangcheng Expressway was plotted.In view of the problem of serious road surface reflection cracks in highways in cold regions of Hebei Province,this paper proposes measures for the prevention and control of basalt fiber reinforcement ribbons along the direction of traffic in semi-rigid bases.And based on the theory of composite micromechanics,the parameters such as tensile modulus,temperature shrinkage coefficient and tensile strength of the stiffened semi-rigid base were estimated.The calculation formula of the temperature stress and the average temperature shrinkage crack spacing of the basalt fiber reinforced semi-rigid base is deduced by using the theory of elasticity mechanics,and the average spacing of the temperature shrinkage cracks in the semi-rigid base layer with different volume fractions of basalt fibers ribbons is calculated.The results show that the reinforcement effect of basalt fiber ribbons can increase the spacing of temperature-shrinkage cracks in semi-rigid bases,thereby significantly reducing the number of thermal shrinkage cracks.Finally,using finite element software to analyze the contrast between different volume fractions of basalt fiber reinforced semi-rigid base and non-stiffened semi-rigid base,the results prove that reinforcement of basalt fiber ribbons can enhance the crack resistance performance of semi-rigid base.