Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
75902 | Microporous and Mesoporous Materials | 2009 | 7 Pages |
In this contribution, the water balance between modified superabsorbent polymer particles of various grain sizes and a hydrating cement matrix is studied both for ordinary and white Portland cements by means of NMR relaxometry. Different approaches for the evaluation of the experimental data are compared: inverse Laplace transforms and several multicomponent fitting models. Both evaluations provide well-comparable results with respect to the overall water quantities absorbed and re-released by the superabsorber. The experimental data indicate fast water uptake within less than 5 min after watering the superabsorber/cement mixture. The re-release of the water begins along with the onset of the hydration reaction and is finished after 1 day for superabsorber powders with a dry grain size below 125 μm and takes about 2 days for larger dry grain size. The water uptake of the superabsorber inside the cement matrix is quantified to about 2250% of its dry weight.