In a collaborative research project called "Consumer Oriented Solids Transport Technology" (COSTT), a uniaxial caking tester was developed to measure the caking propensity of bulk solids under controlled environmental conditions. To validate the results gained from this tester, a series of round robin tests were run, using an organic acid of known humidity dependence as test material. These tests showed that even seemingly minor deviations in the test procedure can cause significant deviations in the measured uniaxial strength. This paper gives an indication of the level of details required to run a reliable caking test and the obtainable reproducibility.

When modeling the caking properties of bulk solids, it is not only necessary to incorporate the yield properties of individual particle contacts, but also to extend them to a many-particle system. To accomplish this by means of Distinct Element Method (DEM) simulations a contact model for (spherical) particles, including a yield criterion for combined load is proposed. An application to the simulation of a caking test is presented and compared to experiments.