EFFECTS OF SILANE-TREATED SILICA FUME ON DAMPING PROPERTY OF CEMENT MORTAR

摘要

Surface modification technique of materials may improve greatly the damping ability of materials. Firstly this paper modified silica fume by the use of silane couping agent, and measured the storage modulus and loss tangent of the different cement mortar after filling silane-treated silica fume and as-received silica fume in the cement mortar at the temperature (-30～30℃) and frequency (0.1～2Hz) by the viscoelastic analyzer VA4000; Secondly microanalyzed these cement mortar specimens by X Ray Diffraction (XRD) and Scanning Electron Microscope (SEM), Thirdly explained the mechanism of silane couping agent for surface modification. Experiment results show that the loss tangent of cement mortar which contain treated silica fume compared that contain as-received silica fume increase by 20～200% and storage modulus by 10～20%; microanalysis show that -OH group which come from silane couping agent's -X group hydrolyzing connect with -OH group which come from cement hydration product Ca(OH)_2, then dehydrate and produce Si-O bond, this net structure may be the main reason of improving the loss tangent of cement mortar with silica fume, and the treated silica fume's reducing water and filling function may contribute to the increase of storage modulus of cement mortar with silica fume. These experiment results provide a basic foundation for further research on the combination of organic and inorganic materials.