Development And Structural Performance Research Of Light And High Strength Steel Bridge Deck Paving Materials Based On Polymer Alloy

In the 21 st century,the requirements for steel deck pavement of long-span Bridges in terms of lightweight,high strength and durability are getting higher and higher.The existing asphalt concrete steel bridge deck pavement increases the difficulty of construction of long span steel bridge due to its large thickness,high density and constant load.At the same time,asphalt pavement has limited deformation capacity and high temperature sensitivity.Under the domestic high temperature and heavy load service conditions,pavement cracking,rutting and other diseases are still relatively common,resulting in the service life of steel bridge deck pavement is only about 10 years,which forms a huge contrast with the service life of long-span steel bridge bridge of 100 years.Therefore,it is imperative to develop a light and high strength steel bridge deck paving material and structure.In this paper,based on key industrial generic technology innovation in Chongqing special "Development of light-weight and high-strength paving materials and equipment for steel bridge deck based on polymer alloys",abandoned on asphalt mixture as the inherent thinking of steel bridge deck pavement,creatively put forward based on the lightweight steel deck plate paving materials and structure of the polymer alloy,and structure of polymer alloy surfacing material and performance for the system research.In this paper,the light and high strength characteristics of PC,PPS,HIPS,ABS,PPO,PS,PP and other polymer materials are investigated by the "specific strength" index,and PPS and PP are selected as the basic materials of polymer alloy considering the economic of materials.PPS/β-PP polymer alloy was prepared by extrusion blending of PPS and PP with different proportions.The bulk properties and crystallization properties of the polymer alloy were systematically studied by means of melt flow performance,FTIR,DSC,TGA,crystallization rate and crystallization kinetics theory,and the synthesis ratio of PPS/β-PP was determined.The mechanism of nucleation,crystal growth and overall crystallization behavior of PPS/β-PP polymer alloy was proposed to guide the preparation of polymer alloy and reduce the inherent defects of polymer alloy.In order to prepare polymer alloy paving materials with both mechanical properties,working performance and economy,this paper takes tensile strength,elongation at break and processing temperature as the investigation indexes,takes PPS/β-PP polymer alloy as the basis,selects thermoplastic elastomer,hard asphalt,toughening resin and inorganic filler as admixtures.Through orthogonal test,the reasonable proportion of polymer alloy pavement material blend was determined,and the compatibility of the polymer alloy pavement material was improved by capacitation modification technology,and the polymer alloy pavement material with stable performance and good economy was obtained.Then,the technical requirements of polymer alloy paving materials were put forward through experimental research on their machining properties,mechanical properties,high and low temperature properties and fatigue properties,and the fatigue prediction equation of polymer alloy paving materials for steel bridge deck was established.Then,this paper combines the application experience of steel bridge deck paving technology and the characteristics of polymer alloy paving materials,put forward a variety of polymer alloy paving materials as the main body of the composite structure of steel bridge deck pavement,carry out the combination of the structure of the interface bonding performance,high and low temperature performance,fatigue performance,such as anti-sliding performance test and research.According to the test results,two kinds of polymer alloy pavement structures with excellent comprehensive performance and good economy are recommended: polymer alloy pavement material + high elastic modified asphalt SMA structure and polymer alloy pavement material + ultra-thin anti-sliding layer structure.Finally,in this paper the pavement model of steel structure suspension bridge is established.The stress and deformation distribution characteristics of beam structure is analyzed,as well as the influence of loading position,load distribution and size on the mechanical properties of polymer alloy pavement structure of the two recommended steel deck.And some suggestions for the optimization of polymer alloy pavement structure are put forward.