کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1457614 | 989271 | 2007 | 7 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: NMR studies of pore formation and water diffusion in self-hardening cut-off wall materials NMR studies of pore formation and water diffusion in self-hardening cut-off wall materials](/preview/png/1457614.png)
Cut-off walls for the containment of polluted sites are vertical in-ground barriers of low hydraulic conductivity. To construct these barriers, self-hardening watery suspensions of a special cement-based hydraulic binder and a cement-stable bentonite are used. The formation of the pore structure during hardening of suspensions with different solid contents and the water self-diffusion in the resulting cut-off wall materials were studied by non-destructive 1H NMR techniques. It was found that an increased amount of hydrating solids in the suspension leads to a decrease in NMR relaxation times and self-diffusion coefficients of the pore water, indicating a reduction of the pore sizes and an enhancement of the diffusion resistance. The self-diffusion coefficients of the water in the hardened cut-off wall materials were determined to be about four orders of magnitude smaller than in bulk liquid water and two orders of magnitude smaller than in pure bentonite–water suspensions confirming the excellent diffusive resistance of the cut-off wall materials.
Journal: Cement and Concrete Research - Volume 37, Issue 6, June 2007, Pages 902–908