Table 13.

ANOVA for 28-day splitting tensile strength.

Variance Source	Sum of Squares	Df	Mean Square	F Value	Significance	Contribution of Factor (%)
$w/b$	1.617	2	0.809	9.417	0.002	49.72
GGBS content Δ	0.405	5	0.081
Fiber content Δ	0.036	2	0.018
Error	0.847	8	0.106
Error Δ	1.288	15	0.086
Total	2.906	17

Note: The effects of GGBS content and fiber content are within the error.