RAP粒径对水泥稳定再生混合料的性能影响研究

为了研究旧沥青混凝土对水泥稳定再生混合料的性能影响,拟定了4种粒径范围的RAP替代相同粒径范围的RBP集料,对比采用骨架密实级配和悬浮密实级配的再生混合料,通过室内力学试验进行分析,并利用电子显微镜对RAP替代不同粒径RBP的混合料界面进行观察.试验结果表明:采用骨架密实和悬浮密实级配的混合料,当RAP替代粒径大于4.75mm,随着RAP替代粒径的增大,再生混合料的强度、模量均有明显降低,干燥收缩系数逐渐增大.粒径范围为2.36~4.75mm的RAP集料替代相同粒径范围的RBP集料,采用骨架密实级配的水泥稳定再生混合料,强度和模量降低幅度较小,同时干燥收缩系数有明显提高,RAP粒径越小,RAP与RBP界面融合程度越高.

Effect of RAP Diameter on the Performance of Cement Stabilized Regeneration Mixture

Four kinds of diameter scopes of RAP (reclaimed asphalt pavement),which were prepared to replace RBP (reclaimed base pavement) in the same diameter scope,were designed for the cement stabilized recycled mixture,in order to study the impact of old asphalt concrete on the performance of recycled mixture.The performances of the regeneration mixtures of skeleton dense gradation and suspended dense gradation were compared by indoor mechanics tests,and at the same time the electron microscope was used to observe the interface of the mixtures in which RBP was replaced by different partical sizes RAP.The results show that the strength and modulus of the regeneration mixture decreases and the drying shrinkage coefficient increases with the aggrandizement of the diameter of RAP substitution,when the RAP diameter is larger than 4.75 mm.The strength and modulus of the cement stabilized aggregate of skeleton dense gradation decrease slightly,while the dry shrinkage coefficient is obviously improved,when the diameter scope of RAP is 2.36~4.75 mm.The smaller the particle size of RAP,the easier the fusion at the interface between RAP and RBP.