Influence of Rice Husk Ash Fineness on the Hydration and Microstructure of Blended Cement Paste
The objective of this paper is to present the results of a study of the effect of fineness of rice husk ash (RHA) on the hydration processes and microstructure of blended cement paste. The hydration processes were studied by means of isothermal calorimetry and the microstructure was studied by means of Mercury Intrusion Porosimetry. Experiments were performed on cement paste mixtures with water to binder ratio (wbr) of 0.25 and 0.40. The cement replacements by RHA were 10％ and 20％. The different mean sizes of RHA particles are about 22.5, 15.5, 9.0, 5.6 and 3.6 um. The samples were cured at 20°C. The study shows that the addition of RHA results in less heat release and decelerates the hydration of Portland cement. The finer RHA blended cement, the higher the total heat evolution and the lower porosity, especially when more RHA is added. The pore size distribution of cement blended with the RHA particle size of 15.5 um is similar to that of the control mixture. It is also shown that the effect of RHA on the total heat evolution of cement is larger than that of SF at low wbr. The porous structure of RHA observed in this study collapses gradually when its mean size reduces from 22.5 um to 9.0μm. The reasonable mean size of RHA particle was proposed from 9.0 to 5.6 μm.
hydration isothermal calorimetry mercury intrusion porosimetry rice husk ash fineness
Nguyen Van Tuan Guang Ye Klass van Breugel Bui Danh Dai
Faculty of Civil Engineering and Geosciences, Delft University of Technology,P.O. Box 5048-2600 GA, Faculty of Civil Engineering and Geosciences, Delft University of Technology,P.O. Box 5048-2600 GA, Department of Building Materials, Hanoi University of Civil Engineering, 5 Giai phong Road, Hanoi, V
国际会议
济南
英文
325-332
2010-05-09（万方平台首次上网日期，不代表论文的发表时间）