The Research On The Adaptability And Mix Design Method Of Pavement Fiber-reinforced Chip Seal

Fiber-reinforced chip seal is a new preventive maintenance, it refers to using coreequipment of fiber-reinforced chip seal and sprinkling two layers of asphalt binder and a layerof fiber, then spreading aggregate on it, and finaly pressing by glue wheel road roller toaequire the structural. Compared with other traditional preventive conservation measures, ithas a higher abrasion resistance, water resistance, crack resistance and stability. There is nostandard specification and technical requirements regarding to adaptability, materialsselection, mix design,and usually it selects the type of materials and determine the materialmixture ratio by virtue of the experience of engineers, resulting in large variability.This paper attempts to determine the adaptability and mix design mothod accroding tothe realistic situation. First, the paper considers the impact of roughness, pavement surfacecondition, surface modulus, ambient temperature and road traffic on the performance andstress of the fiber-reinforced chip seal from the angle of the pavement performance evaluation.And it suggustes that adopting fiber-reinforced chip seal in roads whose technical degree is ofor under the second degree when the IRI is no more than9m/km, crack width is no more than2mm and mostly vertical and horizontal crack, the temperature is normal, overloadphenomenon is not serious.Secondly, it determines the appropriate test items and methods onthe basis of the location and function of the fiber-reinforced chip seal, including mechanicaldesign index and pavement performance test index, such as shear strength, tensile strength,ultimate tensile strain, water permeability coefficient, texture depth and BPN. Combiningwith the asphalt pavement design specification, it determines method of calculation of theinterlaminar shear strength index and tensile stress index and tensile strain index, meanwhile,calculates the tensile stress and tensile strain indicators and shear strength parameters by finiteelement soft ware, considering the load, temperature and cracks of the old road.In order tomake the mix design more effective, it has sudied the relationship between materialsconsumpution and strength, and it gets the relational expression of fiber volume percentageand strength. Meanwhile it puts forward the simplified method of mix design, which is gettingthe relationship expression and predicting the tensile strength and ultimate tensile strain withit.Finnaly, referring to the experience of laboratory test and construction and designationabout foreign chip seal, combining with the requirements of performance and previousanalysis, it determines the requirements of materials selection.And based on the previousfindings, it ultimately determines the fiber-reinforced chip seal design process.