Prefabricated Concrete Elements for the facade Industry with Nano cement composites containing silica fume, nano-silica and TiO2

Using mineral admixtures in cement composites as a way to improve their mechanical and durability properties is a common practice in concrete technology. Among them silica fume and nano-silica effectively influence the composite's early and long-term properties. Due to the limited particle size distribution of nano and micro silica it is expected that the incorporation of some mineral additives with a size of greater than 500 nm may result in better mechanical and durability performance because of the filler effect. In this study, the effect of different percentages of TiO2 on mechanical properties of cement composites containing nano-silica and silica fume was investigated. Six designs were tested for compressive strength with respect to zero, 2.5 and 5 percent replacement of cement with TiO2. The addition of TiO2 has led to an increase in compressive strength. The best results from the sample with 2.5% TiO2 are obtained. This could be due to the effect of TiO2 particles filling. Comparison of SF3, SF2 and SF1 at 28 days of age showed that SF2 increased the compressive strength. This shows that TiO2 has a great potential for improving the mechanical properties of composite cement.The results showed that the addition of TiO2 had a positive effect on compressive strength. Increasing TiO2 nanoparticles content of more than 3 wt% are caused to reduce the compressive strength acording to past studies. But in this study is shown that by adding 3% nanocillis or 20% silicafium to increased TiO2 nanoparticles content of more than 3% wt, the results of compressive strength are not reduced. The use of 3% combined nano-silica or 20% silicafium will cover this defect of increased TiO2 nanoparticles content of more than 3% wt.