Influence of Polymers and Fibers on Early Hydration and Microstructure of Gypsum-based Materials
LIU Chuanbei1, GAO Jianming2, MENG Liyuan3, LIU Laibao1, ZHANG Lihua1, ZHANG Hongping1, LUO Xu2
1 School of Materials Science and Engineering, Southwest University of Science and Technology, Mianyang 621010, Sichuan, China 2 School of Materials Science and Engineering, Southeast University, Nanjing 211189, China 3 Nanchong Sixin Building Materials Co., Ltd., Nanchong 637973, Sichuan, China
Abstract: It is of great significance to study the early hydration and microstructure of gypsum-based materials (GM) for understanding the working mechanism of different admixtures and improving the workability of pastes. Therefore, in this work the early hydration and microstructure of GM pastes containing polyvinyl alcohol (PVA), butadiene styrene rubber (SBR), polyvinyl alcohol fiber (PVAF) and polypropylene fiber (PPF) were investigated by the hydration heat test method, oscillatory rechnology test method and environment scanning electron microscope (ESEM) coupling with liquid nitrogen cooling method. The results show that the early hydration of GM pastes can be divided into four stages, which are the dissolution of hemihydrate particles, the nucleation, growth of dihydrate crystals and the formation of crystal-network-structures (CNS).It has been pro-ven that both polymers can be adsorbed on hemihydrate particles, hindering the effective contact and dissolution of particles. Simultaneously, SBR can be also preferentially adsorbed on dihydrate crystals, impeding the growth of crystals and formation of CNS. Besides, both fibers dispersing among gypsum particles can strengthen flocculation structures, and simultaneously PVAF can absorb a lot of free water and calcium ions, which makes the preferential nucleation of crystals on its surface, therefore improving the interface and binding properties between PVAF and pastes.
刘川北, 高建明, 孟礼元, 刘来宝, 张礼华, 张红平, 罗旭. 聚合物和纤维对石膏基材料早期水化与浆体微结构的影响[J]. 材料导报, 2022, 36(8): 20090176-7.
LIU Chuanbei, GAO Jianming, MENG Liyuan, LIU Laibao, ZHANG Lihua, ZHANG Hongping, LUO Xu. Influence of Polymers and Fibers on Early Hydration and Microstructure of Gypsum-based Materials. Materials Reports, 2022, 36(8): 20090176-7.
1 Lucas G. ZKG International,2003,56,54. 2 Chindaprasirt P, Boonserm K, Chairuangsri T, et al. Construction and Building Materials,2011,25(8),3193. 3 Wu H C, Xia Y M, Hu X Y, et al. Ceramics International,2014,40,14899. 4 Zhi Z Z, Huang J, Guo Y F, et al. KSCE Journal of Civil Engineering,2017,21(5),1836. 5 Liu C B, Gao J M, Tang Y B, et al. Journal of Materials Science,2018,53(24),16415. 6 Jin C, Zhao H, Jiang L L, et al. Bulletin of the Chinese Ceramic Society,2015(6),1504(in Chinese). 金纯,赵辉,江莉莉,等.硅酸盐通报,2015(6),1504. 7 Li D, Zhao Z M, Quan S C, et al. Non-Metallic Mines,2019,42(4),44(in Chinese). 李丹,赵志曼,全思臣,等.非金属矿,2019,42(4),44. 8 Çolak A. Materials Letters,2006,60(16),1977. 9 Cao W X, Peng J H, Yi W, et al. Non-Metallic Mines,2018,41(2),48(in Chinese). 曹文湘,彭家惠,易伟,等.非金属矿,2018,41(2),48. 10 Eve S, Gomina M, Hamel J, et al. Journal of the European Ceramic So-ciety,2006,26,2541. 11 Zhu C, Zhang J X, Peng J H, et al. Construction and Building Materials,2018,163,695. 12 Zhang W B, Xiong F, Yu M J, et al. China Concrete and Cement Pro-ducts,2015(10),77(in Chinese). 张维渤,熊峰,余明玖,等.混凝土与水泥制品,2015(10),77. 13 Liu C, Gao J, Tang Y, et al. Materials Letters,2019,234,49. 14 Betioli A M, Gleize P J P, Silva D A, et al. Cement and Concrete Research,2009,39(5),440.