关键词: 再生粗集料, 水泥稳定碎石, 级配, 骨架密实, 抗压性能

Abstract: In some local specifications in China, the gradation of cement-stabilized recycled coarse aggregate distributes in a wide range. In view of this, in the light of the particles interference theory and the maximum density curve theory, we analyze the proportion of recycled coarse aggregate and natural fine aggregate, and summarize the reasonable range of the gradation of skeleton-dense cement-stabilized recycled coarse aggregate. We also compare the compaction characteristic and compressive performance with those recommended in local specifications. Results reveal that when the content ratio of natural fine aggregate to recycled coarse aggregate is 30%-60%, a tightly packed framework structure is formed between coarse aggregates, giving rise to large internal friction angle; the natural fine aggregate and cement hydration product are fully filled, resulting in large cohesive force and skeleton-dense cement stabilized recycled coarse aggregate. The unconfined compressive strength at 7-d age is higher than 3.0 MPa. When cement dosage is 5%, the compaction characteristics and compressive performance of the design graded cement stabilized recycled coarse aggregate are better than those recommended by local specification.

Key words: recycled coarse aggregate, cement-stabilized macadam, gradation, skeleton-dense, compressive performance