New compaction method for the production of large ramming paste samples for 3D mechanical characterization

Abstract

To assess the mechanical behavior of ramming paste, representative laboratory samples must be produced for experimental characterization. Experimental data are necessary to feed three-dimensional creep model where radial strain measurements are required. It is thus imperative to perform measurements on a sample large enough to get significant radial strain amplitude. However, the ISO standard fabrication method is restricted to small-size samples. In the present paper, a different compaction process, adapted from the Proctor method, is proposed in order to get larger cylindrical samples of 100 mm diameter and 200 mm height. The ramming paste samples are produced in multilayer by dynamic compaction, using a falling weight in a circular pattern over the tamped surface. The baked apparent density obtained by X-Ray computed tomography, or CT scan, and the baked mechanical properties such as compressive strength, have been characterized as a function of the number of layers and the number of impacts.