Preparation and Performance of Desulphurized Gypsum-Based Sandless Self-Leveling Mortar

Abstract

Abstract: The desulphurized gypsum-based sandless self-leveling mortar was prepared by desulphurized building gypsum, P·O 42.5 cement, fly ash, limestone ultrafine powder and admixtures as raw materials. The optimal ratio of gypsum-based cementitious material was determined by orthogonal test. The effects of retarder and cellulose ether on the performance of gypsum-based sandless self-leveling mortar were studied. XRD and SEM were used to analyze the hydration products and microstructure of the system, and the mechanism of the admixtures was further studied through the analysis results. The results show that when the mass ratio of desulfurized gypsum, cement, fly ash and limestone ultrafine powder is 16:1:2:1, the strength of material is optimal. The retarder significantly prolongs the setting time of the mortar, but it causes bleeding of the mortar. Cellulose ether improves the water retention of the mortar, but the strength of mortar decreases due to the air-entraining of cellulose ether. The performance of desulfurized gypsum-based sandless self-leveling mortar meets the requirements of “Gypsum-based self-leveling mortar (JC/T 1023—2007)”.

Key words: desulfurized gypsum, orthogonal test, self-leveling mortar, retarder, cellulose ether

CLC Number:

TU526

LIU Jingyu, SHAN Junhong, LI Chun, MIN Jiangning, DU Li, ZHOU Yuan. Preparation and Performance of Desulphurized Gypsum-Based Sandless Self-Leveling Mortar[J]. BULLETIN OF THE CHINESE CERAMIC SOCIETY, 2021, 40(11): 3654-3661.

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