Study on the activation of recycled fine powder of waste concrete

Journal Information

J. Hefei Univ. Tech. (Nat. Sci.), Jul.2023, Vol.46 No.7: 936-940, 971

DOI: 10.3969/j.issn.1003-5060.2023.07.012

Authors

CHANG Zhiwei $ ^{1,2} $, ZHAN Binggen $ ^{1,2} $, WANG Cun $ ^{1,2} $,

(1. School of Civil and Hydraulic Engineering, Hefei University of Technology, Hefei 230009, China; 2. Engineering Research Center of Low-carbon Technology and Equipment for Cement-based Materials of Ministry of Education, Hefei 230009, China)

Abstract and Keywords

Abstract: In order to make full use of waste concrete, it is the key to improve the activity of its by-product recycled fine powder. This paper studies the effects of the two activation methods of physical grinding and chemical excitation on the activity of recycled fine powder and further explores their mechanism of action. The result shows that physical grinding can greatly improve the activity of the recycled fine powder, while the chemical excitation effect is not obvious. Physical grinding can optimize the particle size distribution of the recycled fine powder, thus improving its activity. Through the salicylic acid-methanol dissolution method, X-ray diffraction (XRD) and thermogravimetric (TG) analysis, it is found that the main crystal phases of the recycled fine powder are inert substances such as quartz, limestone and dolomite. The chemical excitation lacks effective objects and thus has limited effect.

Keywords: waste concrete; recycled fine powder; activity index; activation method; mechanism of action

作者信息

常智玮 $ ^{1,2} $，詹炳根 $ ^{1,2} $，王存 $ ^{1,2} $，杨永敢 $ ^{1,2} $，熊科兴 $ ^{1,2} $，余其俊 $ ^{1,2} $

(1. 合肥工业大学土木与水利工程学院, 安徽合肥 230009; 2. 水泥基材料低碳技术与装备教育部工程研究中心, 安徽合肥 230009)

摘要和关键词

摘要: 为了有效利用废弃混凝土，提高其副产物再生微粉的活性，文章研究物理研磨和化学激发2种活化方式对再生微粉活性的影响效果，并进一步探究活化作用机理。结果表明：物理研磨能大幅提升再生微粉活性，而化学激发效果不明显；物理研磨可优化再生微粉的粒径分布，从而提高其活性；通过水杨酸-甲醇溶解法、X射线衍射（X-ray diffraction，XRD）及热重（thermogravimetric，TG）分析可知，再生微粉主要晶相为石英、石灰石和白云石等惰性物质，化学激发缺乏有效的作用对象，因而效果有限。

关键词: 废弃混凝土；再生微粉；活性指数；活化方式；作用机理

Funding

国家重点研发计划资助项目（2020YFC1909902）

合肥工业大学学报(自然科学版)

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