材料期刊网

传统再生细骨料的需水量大、强度低，较难利用。将废弃混凝土全部破碎成细骨料的全再生细骨料技术能够有效提高再生细骨料的性能。在前期研究的基础上，进行了全再生细骨料的制备及其对混凝土性能影响的研究。研究结果表明，全再生细骨料的制备应包括破碎、筛分和整形工艺；全再生细骨料中小于0．075和0．15 mm的细粉对其强度性能有利，不宜去除；考虑到其细粉组成包括石粉，其微粉含量限值可较现有标准有所提高。全再生细骨料相对于传统再生细骨料在性能上有很大改善，胶砂需水量小且强度高，以其配制的 C30和C50混凝土性能明显优于传统再生细骨料。全再生细骨料的胶砂需水量等性能仍不如机制砂和河砂，但其胶砂强度却高于机制砂和河砂；以其配制的混凝土抗压强度(特别是高水胶比时)明显高于河砂和机制砂混凝土，但工作性能略低。综合来看，全再生细骨料能够全取代河砂和机制砂用于制备C30和C50混凝土。

Traditional recycled fine aggregate is hard to use because its water demand is higher and strength is lower.Recycled total-fine aggregate means crushed the total concrete to fine aggregate,it is effective to improve the performance of recycled fine aggregate.Based on the prior period research,the system research on produc-tion of recycled total-fine aggregate and its influence on concrete performance were processed.The results showed that the production of recycled total-fine aggregate should include crush,screen separation and resha-ping;the fine powder less than 0.15 and 0.075 mm is useful for strength,so it is inadvisable removed;consider the fine powder include the stone powder,the content limitation of fine powder can increase than the standard value.The performance of recycled total-fine aggregate has a prodigious improvement than traditional recycled fine aggregate,its water demand of mortar is lower and strength of mortar is higher,and the performance of C30 and C50 concrete of its is better.The partial performance of recycled total-fine aggregate,such as water de-mand of mortar,is still lower than manufactured sand and river sand;but compressive strength of mortar is higher than manufactured sand and river sand.The compressive strength of C30 and C50 concrete of its is obvi-ous higher than manufactured sand and river sand concrete,special in higher water binder ratio,but the con-crete workability of its is lower.Taking one with another,recycled total-fine aggregate can replace all manufac-tured sand and river sand as fine aggregate in C30 and C50concrete.