ZHOU Wenjuan¹, ZHAO Yilin^1a, JI Zhiyuan², NIU Haoxiang^1a, ZHOU Li’an¹

(1a. School of Civil and Transportation Engineering, 1b. Beijing Energy Conservation &Sustainable Urban and Rural Development Provincial and Ministry Co-construction Collaboration Innovation Center, Beijing University of Civil Engineering and Architecture, Beijing 100044, China; 2. China State Construction Land Guangzhou Branch, Guangzhou 510665, China)

Abstract：Waste clay bricks account for a high proportion of construction waste, and the recycled brick powder obtained after crushing and grinding has pozzolanic activity, which can be used as the raw material of geopolymers. The effects of mineral admixture, activator and mass ratio of water to cementitious material (water-binder ratio) on the compressive strength of recycled brick powder geopolymer were studied by orthogonal experimental method, and systematically characterized by microscopic means such as XRD, SEM-EDS and FTIR. The results show that the substitution rate of slag powder and the content of sodium silicate have obvious effects on the compressive strength of recycled brick powder geopolymer. With the increase of substitution rate of slag powder, sodium aluminosilicate hydrate gel changes to calcium aluminosilicate hydrate gel, the compressive strength of recycled brick powder geopolymer is improved. Sodium-containing calcium aluminosilicate hydrate, calcium silicate hydrate and other gels coexist with Ca(OH)₂ crystals in the recycled brick powder geopolymer of high calcium system. Metakaolin promotes the formation of sodium-containing calcium aluminosilicate hydrate gel, increases the degree of polymerization, delays the growth of cracks, and improves the internal microstructure, the compressive strength is increased.

Keywords：recycled brick powder; geopolymer; compressive strength; microscopic characterization

Get Citation：ZHOU W J, ZHAO Y L, JI Z Y, et al. Compressive strength and microscopic characteristics of alkali-activated recycled brick powder geopolymer[J]. China Powder Science and Technology, 2023, 29(4): 36-45.

DOI：10.13732/j.issn.1008-5548.2023.04.004

Received：2022-10-18,Revised：2022-11-14,Online：2023-05-22 09:51。

Funding Project：国家重点研发计划项目,编号:2017YFC0703305。

First Author：周文娟(1977—),女,副教授,硕士研究生导师。研究方向为固体废弃物的资源化利用。E-mail: zhouwenjuan@bucea.edu.cn。