Mechanical and chemical properties of polyvinyl alcohol modified cement mortar with silica fume used as matrix including radioactive waste

This paper discuss the properties of polymer-modified mortars with silica fume. The polymer-modified mortars are using a polyvinyl alcohol (PVA) with different percentages (0% ,3% ,5% ,and 7%) and in the presence of 10 % silica fume (SF), and tested for compressive strengths, leaching of 137- Cs , initial / final setting time and water absorption percentage . Investigations in which methods of Differential Thermal Analysis ( TG, DTG and DTA), Infrared Spectral Technology and X-ray diffraction were applied to determine the effects of polymer modified-cement content with silica fume . The results showed that addition of PVA increases the compressive strength and decreases the porosity. This increase in strength due to the interaction of PVA with cement, which forming new compound that fill the pores and improve the bond between the cement. Also the pozzolanic reaction of the SF increases the calcium silicate hydrates in the hardening matrix composites, forming distinct change in the refinement of the pore structure in cement composites giving fewer capillary pores and more of the finer gel pores.