COLLAR FOR MEASURING THE LATERAL DEFORMATION OF A TEST PIECE DURING COMPRESSION TESTS, SUCH AS UNIAXIAL OR TRIAXIAL COMPRESSION TESTS

摘要

The invention relates to a collar (1) for measuring lateral deformation of a test piece during uniaxial or triaxial compression tests. According to the invention, the collar comprises a metal hoop (2) or a hoop that is made from composite materials, which can clasp the test piece and which is open, the free ends thereof being separated by a distance Δ. The inventive collar is also equipped with means (5) for directly or indirectly measuring the distance Δ between the free ends (3) of the hoop (2), said means comprising a linear variable differential transformer-type probe (6). The invention also relates to a protective sleeve for the test piece, which can co-operate with the collar.