Continuous rise in the prices of steel reinforcement and cement leads, to the search for ways to reduce the weight of the concrete. This reflects on the total cost of the construction project. This also has a significant effect on environmental problems caused by use of huge amounts of cement and steel. In this study we focused on several strengthening techniques for hollow core using polypropylene pipe, polypropylene pipe in addition to silica fume added to the concrete matrix, polypropylene pipe coated with a layer of epoxy resin, polypropylene pipe with both silica fume and epoxy resin and steel pipes in addition to silica fume and epoxy resin .The of steel reinforcement using Ø6mm, Ø8mm andØ10mm to further enhance the concrete matrix was also considered in this study. Investigation of the physical and mechanical properties of standard concrete cubes and beams was considered in this study. In addition to that scanning electron microscope investigation and Energy Dispersive X- ray Analyses were also considered. |