Experimental Investigation of the Size Effect of the Mode I Static Fracture Toughness of Limestone

Table 1

Geometric dimensions of the samples.

Sample number	Sample radius, R (mm)	Sample thickness, B (mm)	Length of the prefabricated crack, a (mm)	Dimensionless length of the prefabricated crack α
NSCB25-1-1	24.86	14.82	9.21	0.37
NSCB25-1-2	24.01	14.86	9.05	0.38
NSCB25-1-3	24.44	14.99	9.78	0.40
NSCB25-2-1	24.15	14.98	12.22	0.51
NSCB25-2-2	24.72	14.86	12.24	0.50
NSCB25-2-3	24.55	14.97	12.23	0.50
NSCB25-3-1	23.94	14.82	14.02	0.59
NSCB25-3-2	24.02	14.98	14.01	0.58
NSCB25-3-3	23.98	14.86	14.02	0.58
NSCB37.5-1-1	37.52	22.77	14.56	0.39
NSCB37.5-1-2	37.96	22.25	15.98	0.42
NSCB37.5-1-3	37.34	22.86	14.53	0.39
NSCB37.5-2-1	36.94	22.87	18.16	0.49
NSCB37.5-2-2	37.11	22.54	18.32	0.49
NSCB37.5-2-3	37.96	22.76	18.43	0.49
NSCB37.5-3-1	36.44	22.96	21.42	0.59
NSCB37.5-3-2	36.33	22.64	21.98	0.61
NSCB37.5-3-3	36.45	22.72	22.04	0.60
NSCB50-1-1	48.42	29.98	19.9	0.41
NSCB50-1-2	48.53	29.98	19.9	0.41
NSCB50-1-3	48.87	29.99	19.9	0.41
NSCB50-2-1	48.2	29.96	23.88	0.50
NSCB50-2-2	48.89	29.89	24.05	0.49
NSCB50-2-3	48.89	29.89	24.09	0.49
NSCB50-3-1	49.01	29.99	29.36	0.60
NSCB50-3-2	48.24	29.82	28.89	0.60
NSCB50-3-3	49.12	29.99	28.89	0.59
NSCB75-1-1	73.03	45.01	29.23	0.40
NSCB75-1-2	73.99	49.87	29.95	0.40
NSCB75-1-3	72.58	44.79	29.01	0.40
NSCB75-2-1	74.98	44.87	37.05	0.49
NSCB75-2-2	74.01	45.01	37.95	0.51
NSCB75-2-3	74.33	44.89	37.96	0.51
NSCB75-3-1	74.05	44.82	45.03	0.61
NSCB75-3-2	74.89	45.12	45.22	0.60
NSCB75-3-3	74.11	44.53	44.53	0.60