In recent years, so-called hybrid towers have become the standard solution for modern wind turbine towers. The upper part of these towers consists of several steel tubes, while the lower part is assembled from precast concrete elements. These segments are stacked on top of each other and clamped together by external tendons. The horizontal joints between the segments are designed as dry and smooth joints. For transport purposes, the concrete rings are divided into half-shells by additional vertical joints. However, due to multi-segmentation and complex loading conditions, the load transfer in dry joints is not yet fully understood. For this aim, two scaled tower tests with dry and grounded horizontal joints were conducted. Each test involved three stacked concrete ring segments at a scale of 1:10. Test 1 examined the influence of imperfections in the dry joint on the normal stress distribution under pure prestressing. Test 2 investigated the effects of vertical joints in the structure on the stress distribution under prestressing and torsion by dividing the middle segment into a pair of half-shells. 3D scans of the segments prior to testing, combined with suitable measurement equipment, revealed that both imperfections and vertical joints significantly influence the normal stress distribution in horizontal joints. There are pronounced stress concentrations in the joint over the circumference, which correlates strongly with the detected geometric irregularities, such as locally in the area of the vertical joints. However, current regulations and design approaches assume a uniform stress distribution in concrete joints. Therefore, these approaches are currently insufficient for describing the actual load transfer in dry concrete joints under prestressing and torsional loads.