EFFICACY OF SODIUM CARBONATE AND CALCIUM CARBONATE IN STABILIZING A BLACK COTTON SOIL
The problem of damage to structures in expansive soils is world wide. These soils are very often referred as black cotton soils. The properties of black cotton soil may be improved to make the soil suitable for construction purposes. There are several techniques to improve the soil properties like sand cushions, CNS layer techniques, sand columns, stone columns, vibration techniques and by adding chemicals etc. Among these, chemical stabilizing is more expensive than other types of stabilization methods. But the main advantage of it is that setting time and curing time can be controlled. The efficacy of sodium carbonate and calcium carbonate is stabilizing a black cotton soil is presented in this paper. The efficacy of calcium carbonate is much better than sodium carbonate from strength and stability point of view.
Effets des cendres volantes sur le comportement mécanique de sédiments méditerranéens traités à base de ciment et de chaux
1. LUNAM, IFSTTAR, Institut Francais des Sciences et des Technologies des Transports, de l’Amenagement et des Reseaux, BP 4129, route de Bouaye, 44332 Bouguenais, France. 2. Universite de Normandie, Unicaen, GRGCE, UMR 6143 CNRS M2C, Caen, 24 rue des Tilleuls, 14000 Caen, France. 3. Institut des Materiaux Jean Rouxel (IMN), Universite de Nantes, CNRS, 2 rue de la Houssiniere, BP 32229, 44322 Nantes Cedex 3, France. yingjie.liang@ifsttar.fr ; daniel.levacher@unicaen.fr
HRTEM study of orthorhombic zirconia in MgO-PSZ
High-resolution transmission electron microscopy (HRTEM) was used to study the phase of orthorhombic ZrO2 formed in magnesia partially stabilized zirconia (MgO-PSZ) during HRTEM specimen preparation. Based on the three reported crystal structures of orthorhombic ZrO2, with the space groups Pbcm, Pbc21 and Pbca, here it is shown that orthorhombic ZrO2 formed in MgO-PSZ has the Pbcm structure.