Table 2.

Average crack length of all mixtures after 72 h.

Specimen	Crack Length (mm)
	Control	NS2%	NS4%	NS6%	BN2%	BN4%	BN6%
1	120	75	60	68.5	100	72.5	90
2	112	70	60	70	105	70	85
Average	116	72.5	60	69.25	102.5	71.25	87.5