Optimization of River Sand with Spent Garnet Sand in Concrete Using RSM and R Programming Packages

Table 6

ANOVA response 1: compressive strength at 28 days (RStudio).

	Estimate	Std. error	value		Remarks
(Intercept)	4.5586076	0.5397254	8.446	7.30e-06	Significant
A	0.0702722	0.0041188	17.061	1.01e-08	Significant
B	NA	NA	NA	NA	Insignificant
AB	-0.0007530	0.0002367	-3.181	0.00981	Significant