The Effect of Red Mud Content on the Compressive Strength of Geopolymers under Different Curing Systems

Buildings

Yanhui Niu¹  Yao Zhang¹  Tao Ai¹  Jingshan Zong¹  Xin Yan¹  Danni Zhong¹ 

[1] The School of Materials Science and Engineering, Chang’an University, Xi’an 710064, China;

关键词: red mud;    metakaolin;    fly ash;    geopolymer;    curing system;    compressive strength;   

DOI  :  10.3390/buildings11070298

来源: DOAJ

【 摘 要 】

To maximize the utilization of red mud in geopolymers, a red mud–metakaolin (RM-MK) geopolymer and red mud–fly ash (RM-FA) geopolymer were prepared, respectively. The effects of red mud content on the compressive strength and microstructure of the geopolymers were investigated under three different curing conditions. The results showed that the strength of the geopolymer decreased linearly with an increase in the red mud content, whether curing at room temperature or 80 °C. Surprisingly, curing in an autoclave, the appropriate amount of red mud had a favorable impact on the mechanical properties of the geopolymers. When the amount of red mud was 50%, the strength of the RM-MK geopolymer reached its highest compressive strength, 36.3 MPa, and the strength of the RM-FA geopolymer reached its highest at 31.7 MPa. Compared with curing at low temperature, curing the red mud-based geopolymers under a higher temperature and higher pressure can maximize the use of red mud. XRD analysis indicated that zeolite minerals formed. The SEM results showed that the geopolymers cured in an autoclave had a dense structure.

【 授权许可】

Unknown