The Development and Characterization of Zirconia-Silica Sand Nanoparticles Composites

The present study aims to develop zirconia-Silica sand nanoparticles composites through powder processing route and to study the physical properties, mechanical properties and microstructure of the composites. Zirconia based silica sand nanoparticles composite with 5, 10, 15 and 20 wt.% were developed through powder processing technique and sintered at 1500 ℃ for two hours. A decreasing trend of green density however an improvement in sintered density was observed. Also the addition of silica sand nanoparticles with 20 wt.% increased the hardness up to 12.45 GPa and microstructures indicated the diffusion mechanism of silica sand nanoparticles into pore sites of the composites.

Influence of accelerated curing on the compressive strength of polymer-modified concrete

In recent building practice,rapid construction is one of the principal requisites.Furthermore,in designing concrete structures,compressive strength is the most significant of all parameters.While 3-d and 7-d compressive strength reflects the strengths at early phases,the ultimate strength is paramount.An effort has been made in this study to develop mathematical models for predicting compressive strength of concrete incorporating ethylene vinyl acetate(EVA)at the later phases.Kolmogorov-Smirnov(KS)goodness-of-fit test was used to examine distribution of the data.The compressive strength of EVA-modified concrete was studied by incorporating various concentrations of EVA as an admixture and by testing at ages of 28,56,90,120,210,and 365 d.An accelerated compressive strength at 3.5 hours was considered as a reference strength on the basis of which all the specified strengths were predicted by means of linear regression fit.Based on the results of KS goodness-of-fit test,it was concluded that KS test statistics value(D)in each case was lower than the critical value 0.521 for a significance level of 0.05,which demonstrated that the data was normally distributed.Based on the results of compressive strength test,it was concluded that the strength of EVA-modified specimens increased at all ages and the optimum dosage of EVA was achieved at 16%concentration.Furthermore,it was concluded that predicted compressive strength values lies within a 6%difference from the actual strength values for all the mixes,which indicates the practicability of the regression equations.This research work may help in understanding the role of EVA as a viable material in polymer-based cement composites.