花岗岩-钢渣沥青混合料抗滑衰变特性研究

Study on Anti-skid Decay Characteristics of Granite and Steel Slag Asphalt Mixture

以花岗岩粗集料和钢渣细集料按体积比进行混掺来制备沥青混合料(GSAM),级配类型选择AC-13和SMA-13,并将其与对应的石灰岩沥青混合料(LAM)的路用性能及抗滑性能进行对比分析。利用三轮磨耗仪模拟沥青路面的抗滑性能衰减过程,并使用动态摩擦系数测试仪以及激光纹理扫描仪对磨耗过程中混合料表面的抗滑数据进行采集,探究了混合料在不同集料种类以及级配类型下摆值(BPN20)、动态摩擦系数(DF80)、平均断面深度(MPD)等抗滑性能指标的衰减规律。结果表明:两种级配的GSAM高温稳定性、低温抗裂性和水稳定性等基本路用性能均满足规范要求,且在整体性能上优于对应的LAM。GSAM和LAM在磨耗作用下的抗滑性能呈现出的衰减趋势基本一致,基本上分为衰减速率较快且衰减率较高的衰减期以及衰减速率较慢的稳定期,且GSAM具有较强的抗滑性能,在相同的级配条件下,LAM具有较大的衰减速率,GSAM的抗滑指标衰减终值较大;沥青混合料在磨耗过程中测得的MPD,BPN20与DF80具有良好的相关性,可以利用MPD推算各沥青混合料在磨耗过程中的BPN20和DF80;沥青混合料抗滑耐久性可以采用经验模型中的对数模型进行回归分析,3个指标中MPD对抗滑性能衰减规律的拟合效果较好,可以较好地反映沥青混合料路面构造深度与磨耗次数间的关系。

the asphalt mixture(GSAM)is prepared by mixing granite coarse aggregate and steel slag fine aggregate according to the volume ratio.Select grading types AC-13 and SMA-13,the pavement performance and anti-sliding performance of the asphalt mixture and the corresponding limestone asphalt mixture(LAM)are comparatively analyzed.The attenuation process of anti-sliding performance of asphalt pavement is simulated by using three-wheel abrasion tester,and the anti-sliding data of the mixture surface during the abrasion process are collected by using dynamic friction coefficient tester and laser texture scanner.The attenuation rules of anti-sliding performance indicators such as pendulum value(BPN2o),dynamic friction coefficient(DFso),average sectional structural depth(MPD)in dfferent aggregate types and grading types are discussed.The result shows that(1)The anti-sliding performance of CSAM and LAM under the action of abrasion has the same attenuation trend,which is basically divided into the attenuation period with fast and high attenuation rate and the stable period with slow attenuation rate,and GSAM has strong anti-skid performance.Under the same grading condition,LAM has large attenuation rate,while the final attenuation value of anti-skid indicator of GSAM is large.(2)There is a good correlation among the measured MPD,BPN2o and DFso during the wearing process of asphalt mixture.The MPD can be used to calculate the BPN2o and DFso of each asphalt mixture during the wearing process.(3)The logarithmic model in the empirical model can be used for regression analysis of the anti-skid durability of the asphalt mixture.Among the 3 indicators,the fitting effect of MPD on the attenuation rule of anti-skid performance is good,which can better reflect the relationship between pavement structure depth and abrasion times of the asphalt mixture.(4)The basic road performance of GSAM of the 2 gradations,such as high temperature stability,low temperature crack resistance and water stability,meet the requirements of the specification,and their overall performance are superior to those of the corresponding LAM.