建筑废弃物除尘粉的组分特性及其对水泥净浆力学性能的影响研究

Study on composition characters of recycled powder from C&DW and its effect on the mechanical properties of cement paste

为了明确建筑废弃物除尘粉的组分和工程特性,对除尘粉的粒度分布、化学和矿物组成、微观形貌进行了测试分析,并对掺加除尘粉后水泥净浆的抗压强度进行了测试。结果表明:除尘粉颗粒粒径小,比表面积大,粒径分布较均匀;除尘粉的化学组成和粉煤灰相近,但CaO含量较高,Al2O3和Fe2O3含量较低;掺加除尘粉后,水泥净浆的抗压强度呈下降趋势。在水化早期,掺加除尘粉对水泥净浆的抗压强度影响较大,但随着龄期的延长,除尘粉对水泥净浆抗压强度的影响逐渐减小。同时,随着龄期的延长,抗压强度增长速率随着除尘粉掺量的增加而增大。

In order to further clarify the composition properties and engineering characteristics of the recycled powder(RP)from construction and demolition wastes,the basic properties including particle size distribution,chemical and mineral composition,micro-morphology were first studied,and compressive strength of cement paste with RP was analyzed in this paper. The results showed that:the RP possessed a small particle size,large specific surface area,and uniform particle size distribution;the chemical composition of the RP was similar to that of fly ash,while its CaO content was higher,and the content of Al2 O3 and Fe2 O3 was lower than fly ash. The compressive strength of the cement paste with RP showed a downward trend. In the early age of hydration,the content of RP presented a great influence on the compressive strength. With the development of hydration,the influence was gradually reduced. Meanwhile,the increase rate in compressive strength increased with the increase of RP content.