Application Study On Composite Of Waterproof Membrane And Geotextile In Composite Pavements

At present, ailing cement concrete pavements are faced with heavy maintenance in China. Asphalt mixtures overlay is a prevalent and effective technique. The problems of reflective cracking in composite pavements are studied by home and overseas scholars. But reasonable and feasible technique measure is not formed. In this paper, according to the heavy maintenance engineering of G207(national highway) in Jingmen, application for waterproof membrane and geotextile in composite pavements, and retardation of reflective cracking are discussed.In order to retarding reflective cracking, well waterproofness, enough felting force, steady mechanics capability, standing high and low temperature, endurance, and construction maneuverability must be embodied in the stress absorbing interlayer materials. Hereby, atactic polypropylene polymer modified asphalt waterproof membrane and needle-punched nonwoven polyester filament geotextile are compounded and used as interlayer. According to the engineering application, technique capability of the interlayer is analyzed. Whereafter, based on the birth and development of reflective cracking, retarding reflective cracking mechanism of the interlayer is analysis.In order to demonstrating the necessary and validity of retarding reflective cracking for the interlayer, based on ANSYS, via three-dimensional finite element analysis to composite pavement, mechanics responses of asphalt mixtures overlay are calculated and analyzed. The calculation and analysis indicate that: stress situation of overlay is improved by reducing ratio to length and width of slab; stress and strain are partly bridged over joint or cracking by the interlayer; partial strain energy of cracking peak is absorbed by the interlayer; in this engineering, interlayer can reduce 6cm to overlay's thickness theoretically; stress peak value of overlay is decreased by enhancing intensity of the ailing base.Depending on G207 engineering, construction technique of composite pavement including interlayer is studied. And application effect of interlayer is summarized. Some key problems in heavy maintenance engineering are put forward.As a new technique measure, the successful application of interlayer is proved by practice. It has good economy benefit and society benefit. And it can be use for reference to similar engineering.