کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1457785 | 989280 | 2007 | 6 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Impact of zeta potential of early cement hydration phases on superplasticizer adsorption Impact of zeta potential of early cement hydration phases on superplasticizer adsorption](/preview/png/1457785.png)
The zeta potential of early hydration products of cement was found to be a key factor for superplasticizer adsorption. A highly positive zeta potential results in a strong superplasticizer adsorption whereas a negative zeta potential does not allow adsorption. Synthetic ettringite precipitated from solution shows a highly positive zeta potential, hence it adsorbs great amounts of negatively charged superplasticizer. Monosulfate (AFm) has a less positive zeta potential. Therefore, it adsorbs smaller amounts of superplasticizers. For syngenite, portlandite and gypsum, the zeta potential is around zero or negative. These phases do not adsorb superplasticizers. Consequently, a hydrating cement grain is best represented by a mosaic structure, with superplasticizer molecules mainly adsorbed on ettringite and some on monosulfate and C–S–H nucleated at surface.
Journal: Cement and Concrete Research - Volume 37, Issue 4, April 2007, Pages 537–542