Resilient modulus test by indirect tension

This test method is used for determining the resilient modulus by indirect tension test according to ASTM D 7369 (2011). The test is similar to but not exactly the same as the indirect tensile test specified in CEN EN 12697-26 (2012), Annex C. 

Particularly, although the repetitive compressive load applied is a haversine and is applied along the vertical diametral plane of a specimen, the resilient Poisson ratio, p, is first calculated using the recoverable vertical and horizontal deformations, and subsequently two separate resilient moduli, Mr, are determined the instantaneous resilient modulus and the total resilient modulus. 

The instantaneous resilient modulus is calculated using the instantaneous recoverable deformation that occurs during the unloading portion of one load-unload cycle. 

The total resilient modulus is calculated using total recoverable deformation, which includes both the instantaneous recoverable and the time-dependent continuing recoverable deformation during the rest period portion of one cycle. 

Additionally, in the resilient modulus test, the loading time is approximately 0.1 s and the resting period is approximately 0.9 s, compared to approximately 1 s loading time and 2 s resting period used in the indirect tension test. 

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