| With the rapid development of my country’s economy,the task of road transportation is becoming more and more arduous,and higher requirements for road performance are also put forward.In recent years,scholars have achieved good results in improving the performance of asphalt mixtures by studying modified asphalt and changing mixture gradation.There are relatively few studies on the performance of the interface phase between asphalt and ore,but according to the actual engineering experience,the interface phase is more prone to defects or stress concentration than a single material,which affects the overall service performance.The preparation process of asphalt mixture It will directly affect the interfacial phase properties between asphalt and mineral aggregates.On this basis,from the perspective of asphalt mixture preparation technology,this study conducted an in-depth study on how the technology of ready-mixed asphalt mixture can improve the performance of the asphalt-mineral interface phase.The main research contents of this paper are as follows:1.Mechanism of mechanical properties enhancement of asphalt mixture oil-stone interface in pre-mixed mode.Based on thermodynamic parameters and surface energy theory,the mechanism of oil-rock interface enhancement of asphalt mixture under ready-mix technology was studied in depth,and the contact angle and adhesion of asphalt-mineral interface with and without ready-mix technology were compared and analyzed.achievement.The results show that,compared with the conventional mineral surface,the contact angle of asphalt on the premixed mineral surface is smaller,and the reduction of the contact angle can reach 35%-65%.The transfer and wrapping of the material surface is faster.The calculation results of the adhesion work also show that in the dry state,the adhesion work of the asphalt-mineral interface using the ready-mix technology is about 4% higher than that of the conventional asphalt-mineral interface.The calculation results of spalling work show that compared with the conventional asphalt-mineral interface,the spalling work of the asphalt-mineral interface under the ready-mix technology is reduced by 30%-45%,indicating that its water stability is better.2.Analysis of micromechanical properties of premixed asphalt mixture oil-stone interface based on molecular simulation technology.Through molecular simulation technology,three kinds of ready-mixed binders,three kinds of asphalt and one representative mineral crystal were modeled and verified from the nanoscale scale,and then the interface models and the interface models of three kinds of asphalt and mineral crystals were established.Three kinds of interface models of asphalt and mineral crystals under the ready-mix technology were used to simulate the interaction,adsorption behavior and diffusion laws between asphalt molecules and mineral crystals in the two modes,and the differences between the two modes were compared and analyzed.The simulation analysis results show that the diffusion rate of asphalt molecules on the surface of mineral crystals in ready-mix mode is faster than that of conventional asphalt on the surface of mineral crystals.#asphalt,110# asphalt and bio-asphalt;the simulation calculation results of interface energy show that when 110# asphalt is used as a ready-mixed binder,the interface energy between asphalt molecules and mineral crystals is the largest,and the interface performance is the best,followed by 130# asphalt,Lastly is bio-asphalt.According to the molecular simulation calculation results of the interface between asphalt molecules and mineral crystals in the ready-mix mode,it is most reasonable to select 110# asphalt as the ready-mix binder.3.Technology development of pre-mixed asphalt mixture.Based on the research on the principle of pre-mix technology and the micromechanics of the asphalt-mineral interface,through the center composite design method,the rutting dynamic stability,-10 ℃ splitting strength and freezing-thawing cycle 14 d splitting strength are used as response values.Taking the amount of ready-mixed binder,the first-stage pre-mixing time,the second-stage remixing time and the mixing temperature as the influencing factors,a three-response value design under the influence of four factors was carried out.The four influencing factors are optimized by the central composite design method,and the preparation process development of hot mix asphalt mixture and warm mix asphalt mixture in ready-mix mode is completed,and AC-16,SMA-13,OGFC-16,etc.are given.Optimal preparation process parameters of hot mix and warm mix asphalt mixture in ready-mix mode.4.Analysis of road performance of pre-mixed asphalt mixture.Based on the developed hot mix asphalt preparation process and warm mix asphalt preparation technology in premix mode,the high temperature performance,low temperature performance and low temperature performance of hot mix asphalt mixture and warm mix asphalt mixture in premix mode were investigated.The road performance such as water stability performance was experimentally studied.The experimental results show that the rutting dynamic stability of the pre-mixed asphalt mixture is increased by 10%-20%,the splitting strength is increased by 10%-15%,and the splitting strength of the freeze-thaw cycle is increased by 14 d compared with the conventional asphalt mixture.An increase of 2%-7%. |
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