Search results for "Dimensional instability"
showing 2 items of 2 documents
Chemical and dimensional evolution of cationic ions exchange resins in cement pastes
2013
Ion exchange resins (IERs) are widely used by the nuclear industry to decontaminate radioactive effluents. After use they are usually encapsulated in cementitious materials. However, the solidified waste forms can exhibit a strong expansion, possibly leading to cracking. Its origin is not well understood as well as the conditions when it occurs.In this work, the interactions between cationic resins in the Na+ or Ca2+ form and tricalcium silicate (C3S), Portland cement (CEM I) or Blastfurnace slag cement (CEM III/C) are investigated at an early age in order to gain a better understanding of the expansion process.The results show that during the hydration of a paste of C3S or CEM I containing…
Hygroexpansivity of anisotropic sheets
2015
Dimensional instability, more particularly its component hygroexpansivity, may cause problems in process or end-use situations in which paper or board is in contact with water or subject to changes in ambient relative humidity. Misregistration in printing, curl during copying and calender wrinkles are examples of such defects. In this paper, the in-plane hygroexpansivity of oriented laboratory sheets with different pulps and dried both freely and under restraint is studied. A linear relationship between the drying shrinkage and hygroexpansion coefficient of freely dried laboratory sheets having different fiber orientation anisotropies, was observed. Regardless of both the measurement direct…