Influence of Additives on the Strength and Deformation Behavior of Loam Blocks

After Germany’s planned withdrawal from coal-fired power generation by 2030, the by-product known as FGD gypsum will no longer be available. As an alternative, loam can be utilized as a building material for non-load-bearing interior walls. Recycling loam is advantageous as it is readily available in large quantities. However, its unique properties, such as moisture retention and drying shrinkage, are crucial for its usability. Loam samples are modified with various additives and molded into prisms to investigate and optimize these aspects. These prisms are tested for drying shrinkage and strength behavior. The most effective mixtures undergo further evaluation of their long-term behavior when subjected to changes in moisture—the addition of 20 wt.-% brick dust results in a reduction of the drying shrinkage by 25%. In long-term tests, swelling deformation has been reduced by 35%. This article demonstrates the effectiveness of additives in minimizing moisture-inducted deformations while maintaining the same compressive strength. Additionally, it compares various measuring methods for recording length changes in loam blocks.