沥青路面回收料结团特性的评价指标

Evaluation Indicators for Agglomeration Characteristics of Recycled Asphalt Pavement Materials

针对现有沥青路面回收料结团程度评价指标缺乏、评价方法可靠度不高、无法在实际工程中有效应用的难题,基于不同粒径RAP的抽提筛分试验结果,采用RAP抽提细化度、细度模数比、结团率3个指标综合评价RAP结团程度,分析级配类型、铣刨速度、粒径等因素对结团程度的影响,并评价各个指标的适用性。研究结果表明,各个评价指标均有其优缺点和适用范围,但可以在一定级配范围内反映RAP的结团特性;RAP的结团程度随粒径的增大而降低,采用降低沥青路面铣刨速度的方式有利于降低RAP的结团率;建议将4.75 mm作为RAP粗细分级的临界筛孔,采用细度模数比作为初始RAP进行破碎筛分的依据,采用结团率评价各档RAP的结团程度。

Aiming at the existing asphalt pavement recycled material agglomeration degree evaluation indexes are lacking,the equipment used is complex,and can not be quickly applied in actual engineering production,based on the results of extraction and screening test of RAP with different particle sizes,the degree of refinement of the extraction of RAP,the modulus ratio of the fineness of the agglomerated rate and other indicators comprehensively evaluating the degree of agglomerates,and analyzed the type of gradation,the impact of milling.The effects of grading type,milling speed,particle size and other factors on the degree of agglomeration were analyzed,and the applicability of each index was evaluated.The results show that each evaluation index has its own advantages and disadvantages and scope of application,but can reflect the agglomeration characteristics of RAP within a certain range of gradation;the degree of agglomeration of RAP decreases with the increase of particle size,and it is beneficial to reduce the agglomeration degree of RAP by lowering the milling speed;it is recommended that 4.75 mm can be taken as the critical sieve hole for the classification of RAP,and that the FMR can be adopted as the basis of the overall RAP crushing and screening,and that the agglomeration rate indicator can be adopted to control the degree of agglomeration of each index,and to analyze the influence of each index on the degree of agglomeration.The agglomeration rate index is adopted to control the degree of agglomeration of each grade of RAP.