Table 9.

ANOVA for 28-day compressive strength.

Variance Source	Sum of Squares	Df	Mean Square	F Value	Significance	Contribution of Factor (%)
$w/b$	439.001	2	219.501	44.870	0.000	79.38
GGBS content	52.789	5	10.558	2.158	0.141	5.24
Fiber content Δ	2.014	2	1.007
Error	46.904	8	5.863
Error Δ	48.918	10	4.892
Total	540.709	17

Note: The effect of fiber content is within the error.