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

Table 5

ANOVA response 2: flexural strength at 28 days (Design Expert).

Source	Sum of squares	df	Mean square	value	4 value	Remarks
Model	36.08	2	18.04	157.03	<0.0001	Significant
A - river sand	33.44	1	33.44	291.09	<0.0001	Significant
B - spent garnet sand	0.0000	0	—	—	—	Insignificant
AB	1.16	1	1.16	10.12	0.0098	Significant
A^2	0.0000	0	—	—	—	Insignificant
B^2	0.0000	0	—	—	—	Insignificant
Residual	1.15	10	0.1149	—	—
Lack of fit	1.15	1	1.15	—	—
Pure error	0.0000	9	0.0000	—	—
Cor total	37.22	12	—	—	—