| To meet the needs of green and low-carbon pavement pre-conservation technology,this paper prepares a composite modified emulsified asphalt based on the high strength and high adhesion capacity of waterborne epoxy resin and the good low temperature ductility of SBR latex,and obtains waterborne epoxy-SBR emulsified asphalt(WESEA)with both high and low temperature performance and strong adhesion capacity.Carry out research on the performance and durability of WESEA high viscosity anti-slip thin layers for road use,to provide theoretical support for long-life and good performance pre-conservation technology.The WESEA binder was prepared using a waterborne epoxy system with SBR latex as modifier,using a single cold mix method.The basic performance of WESEA binders was tested and it was found that the high temperature performance,adhesion to aggregates,bond strength and resistance to high temperature deformation of asphalt binders were all improved as the amount of water-based epoxy was increased;Using infrared spectroscopy and fluorescence microscopy to observe the microstructure of the asphalt binder,the tests showed that no new absorption peaks were formed inside the WESEA binder and that the water-based epoxy system gradually formed a dense spatial mesh structure in the asphalt binder as the dosing increased.The water-based epoxy system was found to be significantly effective in modifying emulsified asphalt when compounded with SBR latex and mixed in a physically co-mingled manner.The WESEA binder was aged naturally,coupled with 8M,10 M and 12 M,and 10%WESEA binder was selected to investigate the changes in high temperature performance and creep capacity before and after different aging methods.It was found that the asphalt binder still has certain high temperature performance and elastic recovery ability after ageing treatment,and it was found that its high temperature performance and elastic recovery ability tend to decline less after extending the ageing time.The fluorescence shows that after an ageing time of more than 8M at 10%admixture,there is an obvious fracture and disintegration of the mesh structure and the waterborne epoxy particles become dispersed in the asphalt binder.This indicates that the incorporation of water-based epoxy system can slow down the ageing process of asphalt binders.Adjustment of the MS-3 grade to carry out the mix ratio design at the micro-surface,according to the water immersion 1h wet wheel wear value and load wheel sticky sand test to determine the optimal oil to stone ratio of 7.0%.Construction and road performance tests found that increasing the amount of water-based epoxy could improve the mix time and 60 min cohesion of the mix at the micro-surface,while the 30 min cohesion decreased as the amount of epoxy increased;When the water-based epoxy was mixed at 10%,the 1h WTAT value was 210.2g/m2 and the width deflection rate and rutting depth rate decreased by 41.79% and 51.91% respectively,which revealed that the WESEA high viscous anti-slip thin layer mix had better wear resistance and rutting resistance.A comparison of WESEA high viscosity anti-slip thin layer mixes with SBR micro-surface mixes was carried out to analyse the effect of waterborne epoxy admixture on the durability of micro-surface mixes in terms of water stability,slip resistance,long-term wear resistance and ageing resistance.The 6d WTAT value of285.5g/m2 was found to be reduced by 44.04% for WESEA high viscosity anti-slip thin layer mixes at 10% admixture;A 0.25% and 0.16% lower drop in oscillation value and depth of construction when the number of wheel loads is 30,000 to 50,000 than for the mix at the SBR microsurface;The 1h and 6d WTAT values were reduced by 43.84%and 38.20% respectively after 12 M of ageing treatment,which collectively indicates that the WESEA high viscosity anti-slip thin layer mix has better durability. |
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