Positioning device for measuring concrete expansion and contraction deformation by using noncontact method

The utility model discloses a positioning device for measuring concrete expansion and contraction deformation by using a noncontact method. The positioning device comprises a left pedestal and a right pedestal which are concave, the openings of the left pedestal and the right pedestal are formed relatively, and a distance adjusting locking device is arranged between the left pedestal and the right pedestal. Compared with a conventional noncontact method for measuring the concrete expansion and contraction deformation and a method for directly fixing a probe adjusting holder of a displacement sensor on a die for forming concrete test pieces, the positioning device has the following advantages that: 1) during measurement, the positioning device keeps a certain clearance with a concrete test piece to be tested all the time, so the test error caused by limiting the deformation of the test piece by an end plate of the die is avoided when the concrete expansion deformation is measured, the test error caused by the friction between the test piece and the die is avoided when the concrete contraction deformation is measured, and the positioning device can measure the early expansion or contraction deformation of the concrete test piece more accurately; and 2) the positioning device has simple structure, adjustable length, convenience for operation and wide adaptability.