The Research On High-Temperature Performance Parameter Of Asphalt Binder

Thermal　rutting,　which　will　deteriorate　the　performance　and　shorten　the　service　life　of　asphalt　concrete　pavements,　is　one　of　the　principal　failure　modes　on　roads.　Studies　showed　that　rheological　properties　of　asphalt　binders　play　a　vital　role　in　controlling　this　common　mode　of　failure,　which　have　drawn　great　attentions　from　the　researchers　and　promoted　the　studies　on　relevant　parameters.　This　paper　selects　12　kinds　of　representative　asphalt　binders　,regard　high-temperature　nature　of　asphalt　as　the　focal　point,have　a　large　number　of　routine　tests,dynamic　shear　tests,the　repeated　creep　tests　and　frequency　scanning　tests,to　evaluate　in　detail　routine　high　Temperature　index,namely　Softening　point　,the　equivalent　softening　point　and　60　degrees　Centigrade　of　viscidity　at　home　and　abroad　at　present,and　Superpave　high-temperature　index　G * /sinδ　and　its　optimized　indexes　.namely　the　critical　temperature　of　rut　factor　T_{G * /sinδ} ,refinement　factor G ^* /(1-1/sin δ·tgδ),zero　shear　viscidity.the　comprehensive　results　of　the　test　indicate　LgP　and　T　relation　accords　with　the　conic　section　even　more,　equivalent　softening　point,　PI　and　calculates　the　error　is　relatively　great;60　degrees　Centigrade　of　viscidity　are　the　apparent　viscidity,relates　to　tests　state;　It　is　for　rheology　in　temperature　parameter　( G *,G ',G ^''　and δ)　influence　by　result　it　influences　elasticity　of　asphalt　mainly,　influence　the　viscidity　composition　relatively　small;It　is　the　same　basically　in　high-temperature　grade　to　unmodified　asphalt　before　and　after　RTFOT,for　the　modified　asphalt,　because　the　aging　condition　is　insufficient,　high-temperature　grade　is　low　from　one　to　three　grades　after　RTFOT;　The　rheology　parameter　changes　with　magnitude　of　Strain,thickness　of　sample,has　proved　there　is　its　limitation　to　the　modified　asphalt　in　Superpave　supposing　basically　and　model,　all　kinds　of　impact　on　result　of　the　test　of　the　angular　speed　indicates　,　it　can't　be　to　treating　the　asphalt　as　the　same　to　adjust　the　high-temperature　grade　according　to　the　speed;T_{G * /sinδ}　sovles　the　question　that　unable　to　distinguish　good　from　bad　for　asphalts　in　the　same　performance　grade,　but　has　not　carried　research　to　Superpave　high-temperature　index　on　rheology　model　and　mode　of　loading; G * /(1 ? 1/sin δ? tgδ)and　Gv 　remedy　defect　that　G * /sinδ　unable　to　reflect　delayed　elasticity　by　evolving　in　theory　and　mechanics　model,through　validating　asphalt　mixture　performance　by　SST,　sequence　which　each　index　relativity　to　SST　from　lager　to　little　is　　GV ,accumulative　strain,ZSV, G * /(1 ? 1/sin δ? tgδ),60　degrees　Centigrade　of　viscidity,the　equivalent　softening　point,Softening　point　TG * /sinδ, G * /sinδ　relativity　can　reflect　which　index　is　better　to　the　extent.