Optimization of physical and mechanical properties of calcium silicate nanocomposite by Taguchi method

The purpose of this work is to develop a new type of calcium silicate nanocomposite, with low setting time, good workability and high strength. This new nanocomposite is prepared by mixing Nano Fast Cement, Nano Hydroxyapatite, polyvinyl alcohol and colloidal nano silica. The effect of three additives (hydroxyapatite nanoparticles, colloidal nano silica and polyvinyl alcohol solution) on its physical and mechanical properties was investigated. Using Taguchi design method, the effect of different levels of additives and optimum percentages of each additive on having nano composite with high compressive strength, low setting time and good workability were determined. According to the results, the most effective factor on the mechanical properties of nanocomposite (compressive strength, flexural strength and flexibility) is polyvinyl alcohol, that level of three (6%) has the highest signal to noise ratio, indicating that the optimal level for this factor is level three. Also, factor A, which represents the hydroxyapatite nanoparticles, is the signal-to-noise value of all surfaces almost close to each other, indicating that this factor does not have much effect on the mechanical properties. And according to the test results, the most effective factor on the setting time is percentage of hydroxyapatite nanoparticles. The optimal level for this factor is level one (zero for hydroxyapatite). Thus, the optimum percentages for nanocomposite production with the highest strength and the lowest setting time and good workability are 6% polyvinyl alcohol, 0% hydroxyapatite and 0.5% nanosilica.