Research On Anti-Sliding Decay Law Of Asphalt Pavement

With the rapid progress of asphalt pavement construction projects,driving safety has gradually attracted attention.Anti-sliding performance is an important indicator reflecting the safety of road driving.Although the highway meets the specifications when it is completed and accepted,with the extension of the open traffic time,the road anti-sliding evaluation index decays very fast,and the maintenance cost is obviously improved.In this thesis,the anti-sliding decay characteristics of asphalt pavement are studied,which can provide guidance for the design,construction and maintenance of asphalt pavement from the perspective of improving the anti-sliding durability of pavement,and effectively improve the safety of driving.From the perspective of tribological principle,the composition of anti-sliding friction of asphalt pavement is expounded,and the anti-sliding mechanism of asphalt pavement is analyzed.At the same time,the main influencing factors and detection methods of anti-sliding performance are summarized.The anti-sliding performance of the on-site asphalt pavement was selected to analyze the correlation between the evaluation indexes and the distribution characteristics of the anti-sliding lanes.The results show that the depth correlation between the laser method and the sanding method is poor,and there is a certain correlation between the pendulum method and the transverse force coefficient method,but the correlation is not high.Therefore,based on the international friction index,this paper proposes high-speed pendulum value as the anti-sliding evaluation index of friction coefficient of indoor mixture test piece,and proposes corresponding technical requirements.The lane should be the focus when testing the anti-sliding performance of the two-way four-lane road.For the two-way eight-lane road,the slow lane and the outer lane should be the key points,but the surface layer of the lane with too much traffic load may have texture regeneration phenomenon.It should be paid attention to when evaluating the anti-sliding decay in the field.A sanding instrument capable of accurately controlling the amount of sand is developed.The wheeled abrader developed by the research group can accelerate the wear of the asphalt mixture,and the equipment operation method and corresponding test parameters are proposed.The effects of load and temperature on the anti-sliding decay law of asphalt mixture are studied based on wheel wear instrument.The results show that with the increase of the number of wear,the structural depth gradually decreases,and the initial decline is significant,and the later stage tends to be gentle.The high-speed swing under low load shows a transient rise in the early stage of wear,and then declines in a similar way to the structure of deep decay..The structural depth and high-speed pendulum of SMA asphalt mixture are more sensitive to load than AC.When the load is the same,the depth of structure decay is higher than AC,but the high-speed pendulum decay is lower than AC.Since the structural depth and high-speed pendulum stability of AC asphalt mixture are close to the standard lower limit,and SMA is still relatively rich,SMA asphalt mixture is more suitable for heavy-duty traffic road surface layer paving than AC based on operational safety considerations..The higher the temperature,the earlier the structural depth and high-speed pendulum of the SMA asphalt mixture reaches the decay inflection point,while the AC has no obvious law.The high-speed pendulum of SMA asphalt mixture has a higher sensitivity to temperature than AC,but the final decay of both structures is not affected by temperature.Because the structural depth and high-speed pendulum stability of AC asphalt mixture are close to the standard lower limit,and SMA is still relatively rich,SMA asphalt mixture is more suitable for road surface pavement in high temperature areas than AC based on operational safety considerations.Based on the plate type wear meter developed by the research group,the effects of grading and aggregate characteristics on the anti-sliding decay law of asphalt mixture are studied.The results show that,in terms of grading characteristics,the main factors affecting the initial value of the asphalt mixture are the PPCS,oil-stone ratio and FAf index,and the initial value of the pendulum increases with the increase of PNNPS/2 and CA indicators,with PPCS,PSCS,PPCS,PTSC,FAc,FAf and oil stone ratio indicators increase and decrease.Therefore,in order to improve the initial anti-sliding performance of asphalt pavement,the Pscs,oil-stone ratio and FAf index should be appropriately reduced when designing the gradation.The main factors affecting the anti-sliding durability of asphalt mixture are CA,PPNPS/2 and PPCS indicators,while the relative decay degree of the pendulum decreases with the increase of 8 grading parameters.Therefore,in order to improve the anti-sliding durability of asphalt pavement,it is necessary to lower the CA,PPNPS/2 and Pscs indicators.As far as the aggregate characteristics are concerned,the influence of the aggregate type on the initial level of the pitch asphalt mixture is not high,but the higher the needle-like content of the coarse aggregate,the lower the overall anti-slip performance of the asphalt mixture.The main factors affecting the anti-sliding durability of asphalt mixture in the technical index of coarse aggregate are the polishing value,followed by the wear value,and finally the crush value,and the value of the end of the pendulum increases with the increase of the polishing value.The wear value and the crush value increase and decrease.Therefore,in order to improve the anti-sliding durability of the asphalt mixture,the aggregate with high polishing value is preferentially selected,and the aggregate with low abrasion value and low crushing value is selected secondly.