Stochastic Investigation into the Heterogeneity of Multiwalled Carbon Nanotube Infused Clay Bricks

This investigation is primarily focused on addressing the prevailing uncertainty surrounding the compressive strength of three distinct types of bricks: nanomodified; simple; and commercial. Nanomodified bricks are specifically fabricated using a minute concentration of 0.01% w/w multiwalled carbon nanotubes combined with 1% sodium hexametaphosphate. However, the utilization of both materials in a single brick is currently limited. In view of this constraint, a diligent effort was made in this study to comprehend the effects of multiwalled carbon nanotubes and sodium hexametaphosphate as additive materials for brick construction. It is important to note that the compressive strength of the bricks remains the pivotal and critical characteristic under investigation, and an exhaustive analysis was undertaken employing a probabilistic approach. The findings of the study suggest that the variability observed in the compressive strength parameters of nanomodified, simple, and commercial bricks can be explained by a normal distribution at a significance level of 5%. The calculated values for the characteristic compressive strength were determined to be 24.47, 16.47, and $14.24\mathrm{N}/{\mathrm{mm}}^2$, respectively, for the three types of bricks. Further, the regression analysis conducted to assess the relationship between brick compressive strength and the independent variables yielded a cubic fit with $R^2$ (coefficient of determination) values of 0.984, 0.995, and 0.995 for nanomodified, simple, and commercial bricks, respectively. Consequently, the application of multiwalled carbon nanotubes in conjunction with sodium hexametaphosphate in fired clay bricks can be recommended to achieve enhanced compressive strength.