Experimental Research On Performances Of TLA Compound Modified Gussasphalt Concrete

Due to its characteristics of small porosity, high content of asphalt and numerousfine aggregate, Gussasphalt concrete boasts fine performances of water proof,durability, low temperature anti-cracking and natural adaptation to the deformation ofbridge deck, which can be widely used in the bridge deck pavement. The thesis hasdone a laboratory study on mixture ratio and pavement performance of TLAcompound modified asphalt Gussasphalt concrete based on Shiwan bridge deckpavement in Foshan City. Thus it provides reference for the applied of practiceengineering.(1) By mixing the different mixing amount of TLA with A-70#asphalt or SBSrespectively to make TLA modified asphalt and TLA compound modified asphalt, anddoing the researches on various indexes of technical properties within the mixingamount of TLA ranging from60%to80%, the thesis find that TLA, as the modifier,can evidently enhance the softening point of SBS and lower the penetration. Withinthe mixing amount of TLA ranging from60%to70%, it can meet the requirements ofrelated technical indexes. Meanwhile, the blending of TLA and SBS has strongforce-ductility so that its internal cohesion increases apparently and peaks when themixing amount is70%. Accordingly, it selects the TLA compound modified asphaltwhich the mixing amount is70%as the bituminous binder of Gussasphalt concrete.(2) Within the gradation range of the casting type asphalt mixture GA-10tochoose five types targeted gradation, the study makes the TLA compound modifiedasphalt as the binder, then selects five kinds of asphalt-aggregate ratio between12%~14.5%respectively, next makes into casting type TLA compound modifiedasphalt mixture, at last conducts the experiment of LUEER test, penetration test andporosity test. The results show that: when the ratio of asphalt-aggregate ratio isbetween12.5%~13.5%，the LUEER fluidity of every gradation GA-10is between3-20s, the penetration is1-4mm and the porosity is less than1%. It meets therequirements of related technical indexes both at home and broad. The study draws aconclusion through comprehensive analysis that the best asphalt-aggregate ratio offive gradations is selected as13%.(3) In order to test the performance of five gradation TLA compound modifiedasphalt mixture GA-10by conducting the experiments of rutting test, bending test at low temperature and freeze thaw split test, the result shows that the dynamic stabilityof the median gradation GA-10is2156times/mm, when the temperature is15℃,the maximum flexural-tensile strain is7720, and the tensile strength ratio is102.4%.These indexes meet the related technical requirement of Gussasphalt concrete, and aresuperior to other gradations; it shows that the gradation has fine high temperaturestability, low temperature crack resistance and resistance to water damage.Accordingly, the study puts forward the reasonable mixture ratio and technicalperformance indexes of TLA compound modified Gussasphalt concrete.