Print Email Facebook Twitter Effects of the fineness of densified silica fume on the hydration of Portland cement Part of: 4th International Rilem Conference on Microstructure Related Durability of Cementitious Composites· list the conference papers Title Effects of the fineness of densified silica fume on the hydration of Portland cement Author Ni, Chenxin (Nanjing Tech University, China) Yu, Zhuqing (Nanjing Tech University, China) Shen, Xiaodong (Nanjing Tech University, China - The Synergetic Innovation Center for Advanced Materials, China) Date 2021-04-29 Abstract As one of the mineral admixtures, silica fume (SF) with high pozzolanic reactivity is generally used to improve the properties of concrete. Most commercial silica fume used in concrete project is dry densified silica fume (DSF). It consists of a good deal of agglomerates of sizes ranging from 10 μm to several millimeters. The size of the undispersed silica fume is usually larger than that of the cement particle. At present, the effect of DSF on the hydration of cement is lack of studied. In this study, the commercial dry DSF is sifted into three sections (>150 μm, 80 ~ 150 μm, 35 ~ 80 μm) by different sieves. The amount of densified silica fume in mixture is 5% by weight of total binder. The used water/binder ratio (w/b) is 0.5. The effect of the fineness of DSF on the setting time of cement paste is firstly discussed. The hydration process of cement incorporated with different fineness of SF is investigated by a semi-adiabatic calorimetric for 3 days at 20 °C and x-ray diffraction (XRD). The obtained results indicate that the setting time of cement paste increases with the decrease of the fineness of DSF. At the w/b ratio of 0.5, the addition of SF has little effect on the hydration period of cement paste. But the hydration rate of cement is decreased with the increase of the size of DSF particles. Subject finenessDensified silica fumehydration To reference this document use: http://resolver.tudelft.nl/uuid:36dcd52a-345e-4988-a824-938d53dab9c9 Part of collection Conference proceedings Document type conference paper Rights (c) 2021 the authors Files PDF Effects of the fineness o ... cement.pdf 1.37 MB Close viewer /islandora/object/uuid:36dcd52a-345e-4988-a824-938d53dab9c9/datastream/OBJ/view