全再生细骨料的制备及其对混凝土性能影响的试验研究

发布时间：2018-07-23 18:02

【摘要】：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0.15mm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。
[Abstract]:The traditional recycled fine aggregate is difficult to be used because of its high water demand and low strength. The technology of crushing waste concrete into fine aggregate can effectively improve the performance of recycled fine aggregate. On the basis of previous research, the preparation of whole recycled fine aggregate and its effect on concrete performance were studied. The results show that the preparation of the whole regenerated fine aggregate should include crushing, screening and shaping process, and that the fine powder less than 0.075 and 0.15mm in the whole regenerated fine aggregate is beneficial to its strength performance and should not be removed, considering that the fine powder composition of the whole regenerated fine aggregate includes stone powder, The limit value of powder content can be improved compared with the existing standard. Compared with the traditional recycled fine aggregate, the properties of the whole recycled fine aggregate are greatly improved, the water requirement of the cement sand is small and the strength is high, and the properties of the C30 and C50 concrete prepared by the aggregate are obviously superior to those of the traditional recycled fine aggregate. The water demand and other properties of cemented sand of whole recycled fine aggregate are still inferior to that of machined sand and river sand, but the strength of cement sand is higher than that of machined sand and river sand, and the compressive strength of concrete prepared by it (especially when the ratio of water to binder is high) is obviously higher than that of river sand and machined sand concrete. But the working performance is slightly lower. In general, total recycled fine aggregate can replace river sand and machined sand to prepare C 30 and C 50 concrete.
【作者单位】：华南理工大学土木与交通学院亚热带建筑科学国家重点实验室;
【基金】：广东省公益研究与能力建设资助项目(2014B020216001)
【分类号】：TU528

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