Influence of Modified Diatomite on Cement-Based Humidity ControlMaterials Performance

Abstract

Abstract: The natural diatomite was modified by calcination and acid pickling,and then was used to replace some cementitious materials for preparing cement-based humidity control materials.The workability,mechanical properties,moisture absorption and desorption rates of cement-based humidity control materials mixed with natural diatomite was tested and compared with those of the modified diatomite.Based on that,the function mechanism of modified diatomite was investigated comprehensively through characteristics analysis of chemical composition and surface structure of diatomite before and after modification,and characteristic parameters of cement hardened body pore structure.The results show that mechanical properties and humidity-controlling performance of cement-based humidity control materials with modified diatomite are better than those of the natural diatomite with the same dosage.When the diatomite is calcined at 400 ℃ for 2 h and pickled with 50% (mass fraction) H₂SO₄ solution for 12 h,its specific surface area,average pore size and total pore volume increase significantly,and further enhances surface adsorption and capillary channel effect of water in the air.

Key words: diatomite, calcination, acid pickling, cement-based humidity control material, action mechanism

CLC Number:

TU59

FENG Lei, LOU Dai, RAN Ze, WEN Xiaodong, WANG Wei. Influence of Modified Diatomite on Cement-Based Humidity ControlMaterials Performance[J]. BULLETIN OF THE CHINESE CERAMIC SOCIETY, 2021, 40(1): 180-186.

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