Micromechanical study of raw earth stabilization using instrumented indentation

Abstract

Alkali-activated slag is used as a stabilizer in earthen materials to improve their mechanical properties and to reduce their sensitivity to water. The efficiency of this stabilization is assessed through the mechanical characterization of samples made of three stabilized raw earths (RE) with different mineralogical compositions and equilibrated under five different hygrometric conditions. Instrumented indentation tests are used to evaluate the cohesion of the stabilized samples as this testing method allows the characterization of the mechanical properties of brittle porous materials at a local scale. The results show an increase in hardness and elastic modulus and a strong decrease in water sensitivity of the three different RE with increasing slag and activator contents.