Dimension stone used in the construction industry requires durability testing. ASTM C99 describes the test method for modulus of rupture of all types of dimension stone except slate. Principal types are granite, limestone, marble, and sandstone.

The requirements of ASTM C99 for determining the modulus of rupture of dimension stone include the following machine specification & specimen preparations:

  • Apparatus: Test machine accuracy within 1% for the range of 10 to 1000 lbf.
  • Test Specimens: Samples sawed and finished by grinding to a smooth surface to the dimensions of 4" x 8" x 2.25". The 4" x 8" surfaces shall be as nearly plane and parallel as practical.
  • Measuring Specimens: Draw center line on the 2.25" surfaces for the 8" width for positioning the upper loading block. Draw two span lines on the 2.25" surface at 3.5" on each side of the center line for positioning the lower support blocks.
  • Conditioning: The dimension stone specimens can be tested in both dry and wet conditions.

In order to test for modulus of rupture, we propose the use of our Industrial Series 600DX Hydraulic Universal Testing Machine with compression-only capability and I-Series Control Electronics. This machine includes an adjustable crosshead with mounting features to accept and center the upper portion of the flexure test fixture. Additionally, the machine includes a table which permits the centering of the lower portion of the fixture. Instron designed the required fixturing to provide two lower rocker-style supports (1" diameter) and one upper load application block (1" diameter) for 3-point flexure loading according to ASTM C99 specifications.

We recommend Bluehill Universal software as the user interface so the operator can easily set up the test, control test rates and get quick, accurate results after the test. Bluehill software is able to perform all of the data analysis required by ASTM C99 after the test is complete and displays the results on the screen for the operate to evaluate. The results and data are also stored in an Access database for later retrieval and access via a network.

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