| Along with the rapid development of transportation enterprise, the quantity of bridgehas been increasing in a rocket speed. Bridge deck surfacing layer is considered as animportant part of the bridge crane system,which can greatly alleviate the impact of dynamicload on the bridge panel. Bridge deck surfacing layer meet the traffic demands on comfortand smooth, which has attracted more and more attention of the scholars both at home andabroad. Bridge deck pavement is very different from ordinary road pavement, bridge deckpavement layer is directly laid on the cement concrete slab; under the influence factors of thetraffic load, wind load, temperature change, earthquake and so on, the force and deformationis much more complicated than the ordinary highway road, so higher requirements have beenmade on the material’s strength, stability, durability and construction technology. Thanks tothe climate characteristic in seasonal frozen region is high temperature and rainy in summer,cold and dry in winter, higher requirements of road use performance has been made on thehigh temperature stability, low temperature crack resistance, water stability and so on ofbridge deck pavement materials. The suitable time for bridge deck pavement is short and thetemperature is low under the condition of the climate characteristic in seasonal frozen region,which is closely related to the quality of bridge deck pavement. According to the problem ofbridge deck pavement construction in the low temperature environment, this paper putsforward reducing the temperature of mix and compaction of asphalt mixture through mixingthe warm agents, so that the negative influence of low temperature to the construction of thebridge deck pavement can be eliminated. In this paper, based on "the research on typicalstructure and material in expressway viaduct bridge deck pavement" project, the research onmaterial and construction of deck pavement for concrete bridge in seasonal frozen region iscarried out, main contents and conclusions are as follows:1. According to the using conditions and characteristics of bridge deck pavement inseasonal frozen region, combining with the existed research and laboratory test results, this paper suggest to use "5cm SBS modified asphalt concrete (AC-13C)+5cm medium sizedparticle asphalt mixture(AC-16C)" as the choice of bridge deck pavement structure. Whenthe pavement is constructed in autumn and winter at low temperature environment, throughadding Sasobit-LM warm agents in asphalt mixture, the negative influence of lowtemperature to the construction of the bridge deck pavement can be eliminated.2. Through the indoor test, the AC-13C asphalt mixture, AC-13C SBS modified asphaltmixture and AC-16C asphalt mixture are carried out to design the mix proportion, therespective optimum proportion is determined, high temperature stability, low temperaturecrack resistance and water stability of road use performance of the three kind of pavementmaterial are compared. The results show that the AC-13C SBS modified asphalt mixture isbetter than the AC-13C matrix asphalt mixture in every kinds of road use performance, sothat the former is more suitable for the bridge deck pavement layer above; AC-16C asphaltmixture can meet all the requirements of road performance for the bridge deck surfacinglayer below.3. Through the Brinell revolving viscosity test study, it is found that when thetemperature is100-110℃,Sasobit-LM lead the largest change range on viscosity of asphalt,when the temperature of asphalt is below100℃, the viscosity of Sasobit-LM mixedasphalt is higher than the asphalt without the warm agents; When asphalt is higher than110℃, the viscosity of Sasobit-LM mixed asphalt is lower than the asphalt without the warmagents, all the above suggest that Sasobit-LM has the effect of decreasing the viscosity athigh temperature and increasing the viscosity at the low temperature.4. Through traditional viscosity-temperature curve and Marshall Compaction test atvariable temperature, mixing and compaction temperature of WMA are determinedrespectively. Studies show that mixing and compaction temperature of WMA determined bythe traditional viscosity-temperature curve is high, the drop of measured temperature ofmixing and compaction the through adding the Sasobit-LM warm agent in the asphaltmixture is far from enough, this is not consistent with the truth that asphalt viscosity isdecreased obviously after adding Sasobit-LM.5. Through Marshall Compaction test at variable temperature, the mixing and compaction temperature are determined to decline about27℃for SBS modified asphaltmixture with the content of2%Sasobit-LM; the mixing and compaction temperature aredetermined to decline about20℃for90#asphalt mixture with the content of2%Sasobit-LM.6. Through the various road performance testing of WMA, it is concluded thatSasobit-LM can improve the high-temperature stability of asphalt mixture, has no effect onthe low temperature crack resistance and has a slight increase in water stability.7. The study of key technical problems on surfacing layer of warm mix asphalt mixtureconstruction are studied so that to put forward the quality inspection standards of concretebridge deck pavement in seasonal frozen region and ensure the durability of the use of thesurfacing layer; through the test road engineering, the proposed season frozen zone concretebridge deck surfacing material is inspected, according to the results, all the indexes ofpavement can meet the design requirements. |
