Influence of silica fume on drying shrinkage of alkali-activated carbon steel slag  

作　　者：Jin-yan Liu Xiao-tong Deng Qiang Ren Sen Liu Zhi-bin Ma 

机构地区：[1]School of Electric Power,Civil Engineering and Architecture,Shanxi University,Taiyuan,030006,Shanxi,China [2]Institute of Resources and Environmental Engineering,Shanxi University,Taiyuan,030006,Shanxi,China

出　　处：《Journal of Iron and Steel Research International》2024年第12期2953-2970,共18页钢铁研究学报(英文版)

基　　金：This work is supported by the Fundamental Research Program of Shanxi Province in China(202403021211083);the Central Government Guided Local Science and Technology Development Project of China(No.YDZJSX20231A007);the Natural Science Young Foundation of Shanxi Province in China(201901D211178)to which the authors are very grateful.

摘　　要：Drying shrinkage is an important factor affecting the durability of alkali-activated materials.The drying shrinkage of alkali-activated carbon steel slag and the effect of silica fume substitution were studied.The drying shrinkage test lasted for 300 d.The compressive strength,flexural strength,Vickers hardness,mass recovery and drying shrinkage recovery of the samples after drying shrinkage were tested.The hydration products and microstructure were characterized by X-ray diffraction,mercury intrusion porosimetry,thermogravimetry–differential thermogravimetry,and scanning electron microscopy–energy dispersive spectroscopy.The results show that although the chemical expansion compensates for the drying shrinkage in 42 d,the drying shrinkage increases continuously within 300 d.Silica fume affects drying shrinkage by refining pore size and increasing matrix microhardness.Solid surface tension and capillary pressure are the driving forces for drying shrinkage in the early and middle to late stages,respectively.The evolution of drying shrinkage is also influenced by chemical expansion,matrix microhardness and macropore collapse.

关 键 词：Drying shrinkage Alkali-activation Carbon steel slag Silica fume Capillary pressure 

分 类 号：TU528[建筑科学—建筑技术科学]