ASTM C583:15(R2021) pdf free download – Standard Test Method for Modulus of Rupture of Refractory Materials at Elevated Temperatures.
7.2 Following the holding period, move the specimcn to the supporting bearing edges. When possible. an original face of the specimen shall be used for the tension face, that is. the face in contact with the two lower bearing edges. Apply the load parallel to the direction (if known) of pressing of the specimen.
7.3 Control test temperature by the thermocouple that is located within ½ in. (13 mm) of the geometric center of a side face of the specimen when ii is in position for testing. Iloki specimen in testing position 10 mm before testing (Note 6). Temperature shall not vary more than minus 0 plus 20 DF (II °C) from the specified test temperature.
Nim 6—This bold period may he shoitened foe continuously charged furnaces.
7.4 Test temperatures are not specified but must be agreed upon between laboratories and must be included in the report. Test temperatures should be selected in even lOt) ‘F (55 °C) intervals, hut if agreed. other multiples could be used.
7.5 Bring the top bearing edge to bear at mid-span on the specimen, ensure proper alignment of bearing surfaces, and apply pressure through ihe loading mechanism until failure of the specimen occurs. The rate of application of the load on the specimen shall be 175 ± 17.5 lbf (778 ± 77.8 NWmin. The resulting rate of increase in bending stress for the standard I by I by 6-in. (25 by 25 by 152-mm) specimen is 1312.5 ± 131 psi (9.05 ± 0.9 MPaVmin.3 If nonstandard specimens are used, the proper loading rate should be determined from the foregoing stressing rate and full details disclosed in the report.
7.6 Move the other specimens successfully onto the bearing edges and break them in accordance with the preceding procedure.
8. Calculation
8.1 Calculaie ihe modulus of rapture tMOk for each rectangular specimen as tollows:
9. Report
9.1 Report the test lemperatLire. the live individual test results, and the aserage modulus of rupture and standard deviation in lhf/in.2 (or MPa for the five specimens.
9.2 Also, list in the report any deviations from standard test requirements such as specimen sire, span, heating rate, soak time, or loading rate.
10. Precision and Bias
10.1 Ruggedness tests conductcd in 1977 showed that thc most sensitive variables were specimen dimensions, test temperature, and soak time. Of smaller influence were heating rate above 1800 F (980°C) and loading rate. Test results arc incorporated in the method.
10.2 Inrer!aboraiorv Test Data—The results of interlaboratory siudics conductcd in 1963 and in 1970 were uscd in 1979 to revise the precision statements in accordance with latest recommendations from ASTM Committee ElI,
10.2.1 In the 1963 study, four types of direct-bonded (fired) magnesite-chrome brick and two types of chemically bonded magnesite-chrome brick were tested at 1800 <‘F (980 <‘C) and 2300 ‘F (1260 <‘C). Five laboratories tested five specimens of each brick at each test temperature. In the 1970 study, two types of direct-bonded chrome brick, one 95 % MgO fired periclase brick t HOF type), and one 90 I alumina brick were tested at 2700 °F (1480 °C) by four laboratories using 20 specimens of each type of brick.