Specific Fracture Energy Determination of Dam Concrete from Size Effect

A series of tests was carried out based on the size effect due on a number of geometrically similar notched specimens of various sizes.Experimental tests include three-point bending tests.The specimens were of square cross section with span to depth ratio of 3. Three different specimen with depth of 200, 250 and 300mm was considered for the purpose of test. Concrete mixtures are provided from Caroon 3 project site using river gravel or commonly crushed stones from quarries. Effect of aggregate size is considered by using two types of concrete mixture of 75 and 150mm maximum size of aggregate. For concrete mix of 75mm maximum aggregate size, two values of relative notch depths of 0.1 and 0.2 are used. For concrete mix of 150mm maximum aggregate size, only one value of relative notch depth of 0.1 is used. xperimental results show that aggregate size has no important effect on specific fracture energy. According to specific fracture energy definition for an infinitely large specimen, specific fracture energy value of dam concrete is between 130 and 150 N/m