Application of High-Strength Lightweight Concrete in Gob-Side Entry Retaining in Inclined Coal Seam

Table 4

Analysis of variance (slump).

Factors	Square of deviance	Degree of freedom	Mean square	F	F critical value	Significant
Water-cement ratio	50.889	2	25.444	0.852	4.46	No
Volume rate of sand	16.889	2	8.444	0.283	4.46	No
Content of fly ash	24.222	2	12.111	0.406	4.46	No
Silica fume dosages	146.889	2	73.444	2.46	4.46	No
Summation	238.89	8