The effect of local pozzolans and lime additions on the mineralogical, physical and mechanical properties of compressed earth blocks in Argentina

The purpose of this research is to evaluate the mineralogical, physical, and mechanical properties of compressed earth blocks (CEB) stabilized with lime and mineral admixtures easily obtained in Argentina: natural pozzolans and brick powder. the admixture mineralogical composition and their pozzolanic potential as well as the development of hydraulic phases upon reaction with calcium hydroxide (lime) were determined, emphasizing the formation of hydrated cementing compounds. Samples with different percentages of lime and mineral additions were prepared in order to test their compressive strength, wet erosion resistance, and water absorption, and contrasting the results with those of their counterparts stabilized exclusively with lime or cement. The results obtained allow us to affirm that both the brick powder and the pozzolan used have pozzolanic properties and, in combination with calcium hydroxide, form amorphous phases of C-(A)-S-H. However, the use of small amounts of both additions in combination with hydrated air lime in the manufacture of CEB, compared to CEB samples stabilized only with hydrated air lime, adversely affected their physical and mechanical properties.