The mechanical characteristics of on-site manufactured compressed earth blocks: the effects of water repellent and other additives

Abstract

AbstractThe compressed earth block (CEB) is a form of masonry unit comprised of mechanically compacted earth with a natural clay binder. CEBs typically experience a 50% reduction in compressive strength when saturated. As a result, CEBs are typically stabilised with Portland cement, hydrated lime, or metakaolin. More recently, a commercial silane/siloxane water-repellent admixture with the tradename Plasticure, specifically designed for earth construction, has become available. This paper is an experimental investigation of the influence of Plasticure on the dry and wet strengths of CEBs stabilised with Portland cement, hydrated lime, and metakaolin. Prisms were tested wet and dry with three repetitions each. In total, 106 specimens were tested. The wet specimens were soaked in water for 24 h before compressive testing. Typical CEBs without Plasticure absorbed water equal to 7 to 9% of their original weight. This resulted in reductions of compressive strengths from the dry condition by 40 to 50%. For CEBs...