Study On The Performance Of Nano-AAT Composite Modified Asphalt And Its Mixture

Asphalt is still employed as a major material in today’s pavement building projects due to its high road performance and versatility for construction under a variety of environmental effects.Nevertheless,the application of modified bitumen with good qualities to pavements is still constrained by a variety of engineering variables,including cost and procedure.Low-density polyethylene(LDPE)and crumb rubber powder(CRP)were employed to replace some of the SBS and high-density polyethylene(HDPE)to adapt nano-AAT(American Advanced Technology)-modified asphalt with good performance to realistic engineering applications.A combination of macro-and micro-analysis was utilized in this study to assess the performance of the composite modified asphalt binder and to analyze the road performance at the asphalt mixture level,which was then placed in a test section for corresponding testing and analysis.Firstly,physical property index tests,dynamic shear rheology tests,low temperature bending beam tests,Brinell viscosity tests,bonding tests,contact angle tests,multiple stress repetitive creep tests,and rotating film oven tests were conducted on the composite modified asphalt.The SBS-modified asphalt was used as a benchmark to evaluate three composite modification options that were relatively superior,with the addition of additives for final selection.In terms of high temperature performance,physical characteristics,and ageing properties,the A23W-modified asphalt(2%LDPE+3%CRP+2.7%Admixture)is superior to the SBSW-modified asphalt.Additives have a positive effect on the construction and ease of use,low temperature crack resistance and adhesion properties of asphalt materials.Secondly,microscopic analysis techniques such as Fourier infrared spectroscopy and atomic force microscopy were used to investigate the modification mechanism and microscopic morphology of the best composite modified asphalt.The results showed that the modification process of A23W was physically blended and that A23W showed a better ability to inhibit the growth of sulfoxide groups than SBSW during the ageing of the two asphalt binders.This indicates that A23 W has good age resistance.Finally,the road performance of the A23W and SBSW-modified asphalt mixtures was measured and evaluated through high-temperature rutting tests,low-temperature beamlet bending tests,and water stability tests.The two asphalt binders and their mixtures were finally produced,and the actual road performance of the A23W was evaluated by paving a test section.The results show that A23W has better high-temperature rutting resistance and water stability than SBSW,and that A23 W has good practical application capability and is less expensive than SBSW.In terms of material properties,project cost,and construction mixability,the A23W solution presented in this study outperforms SBSW and the original AAT,with positive implications for future practical engineering use.