Research On Double-Layer Paving Technology For Asphalt Pavement

Double-layer paving technology is a new construction technique in asphaltpaving, in this technics two layer mixture were paved and compacted at one time.Compare to traditional crafts double-layer paving can improve layer cohesion station,reduce temperature loss, save construction time, optimize pavement structure andreduce construction costs. nowadays, the research about double-layer pavingtechnology were few, some questions about this technology for example cohesionstrength, temperature losing rate in paving process, reasonable compaction andpavement evenness control were short of systemic study and attention, these questionsrestrict the double-layer paving technology spreading in China.In response to above mentioned issues, this paper this paper mainly to carry outthe following studies:(1) system studied the effecting factors about shear bondstrength between the double-layer, research on the interlocked-denseness under100℃,120℃,140℃,160℃.(2) Through Indoor and scene shearing test, the shear bondstrength between traditional and double-layer were studied, the result show that:compare to traditional construction, double-layer paving technology can improvelayer shear strength31.7%～59.5%, pull strength26.7%～78.5%. This paper alsoestablish a finite element model based damage failure theory to predict the layerstrength.(3) Comparative analysis the2cm,5cm depth temperature losing disciplineunder different construction technology, a numerical model was established tosimulate the double-layer asphalt temperature loss under different ambienttemperature, at last the effective compacting time.(4) Mixture compacted test underdifferent temperature and thickness, orthogonal analysis and multiple regressionmethods were adapted to get the relation among compaction, thickness andtemperature, provide the basis for the double-layer paving reasonable compaction.(5)Double-layer paving pavement roughness probability distribution was obtainedthrough witnessed inspections in experimental road, establish roughness predictionmodel to study the double-layer paving technology smoothness delivering andProposed flatness control standard.(6) Four kinds of pavement structural grouping were paving under double-layer technology, in construction process asphalt mixturetransport paving and compaction working procedures were studied, the theoreticalresearch were application in actual project.In summary, the main question about double layer technology were saved, forexample bond strength between double layers, effective compacting time, reasonablecompaction time and roughness quality control. these research provide theoreticalbasis for the spreading of double layer technology.