Most of the studies on RE stabilisation focus on the mechanical properties of the material on a basis (e.g. 28-day strengths), while long term performance is often ignored. However, weathering cycles over the effect mechanical performance. In this study, we material’s lifespan may investigated the strengths of stabilised rammed earth (SRE) materials, stabilised with either cement or waste materials (i.e. CCR and FA) before and after wetting-drying regimes. Particular emphasis was given to the long-term behaviour of the alternative stabilisation by relating the mechanical properties and durability to material microstructural features. MATERIALS AND METHODS Materials Engineered soil Although several studies on earthen construction indicate that the Particle Size distribution (PSD) cannot be used as a discriminating parameter for the selection of a suitable soil for construction [, ], a heterogeneous PSD, including both fine and coarse particles, is generally recommended when building with earth [, ]. Moreover, laboratory tests tend to underline that the activity of the clayey proportion in the soil is at least as impacting as its PSD []. The base soil used here was a typical in situ soil from Perth, Western Australia, which largely comprised sand. To improve its poor grading, both coarse (gravel) and fine particles (a low-activity silty clay) from local quarries were added. The percentage of the single components were determined following the recommendations made by Houben and Guillaud []. The use of an soil over a natural soil permitted tighter control “engineered” over material mineralogy and grading []. The resulting mixture, which will be referred to as Engineered Local Soil (ELS), was composed of 60% local soil, 30% clayey soil from a nearby quarry and 10% single sized gravel (10 mm). The PSD of the added silty clay, measured according to AS 1289.3.6.1 [] and AS 1289.3.6.3 [], demonstrated a composition of 66% clay and 28% silt. Chemical analysis showed a composition of 65% Kaolin, 28% Quartz and 5% Muscovite. The specific gravity
Most of the studies on RE stabilisation focus on the mechanical properties of the material on a basis (e.g. 28-day strengths), while long term performance is often ignored. However, weathering cycles over the material’s lifespan may effect mechanical performance. In this study, we investigated the strengths of stabilised rammed earth (SRE) materials, stabilised with either cement or waste materials (i.e. CCR and FA) before and after wetting-drying regimes. Particular emphasis was given to the long-term behaviour of the alternative stabilisation by relating the mechanical properties and durability to material microstructural features. MATERIALS AND METHODS Materials Engineered soil Although several studies on earthen construction indicate that the Particle Size distribution (PSD) cannot be used as a discriminating parameter for the selection of a suitable soil for construction [, ], a heterogeneous PSD, including both fine and coarse particles, is generally recommended when building with earth [, ]. Moreover, laboratory tests tend to underline that the activity of the clayey proportion in the soil is at least as impacting as its PSD []. The base in situ soil used here was a typical soil from Perth, Western Australia, which largely comprised sand. To improve its poor grading, both coarse (gravel) and fine particles (a low-activity silty clay) from local quarries were added. The percentage of the single components were determined following the recommendations made by Houben and Guillaud []. The use of an “engineered” soil over a natural soil permitted tighter control over material mineralogy and grading []. The resulting mixture, which will be referred to as Engineered Local Soil (ELS), was composed of 60% local soil, 30% clayey soil from a nearby quarry and 10% single sized gravel (10 mm). The PSD of the added silty clay, measured according to AS 1289.3.6.1 [] and AS 1289.3.6.3 [], demonstrated a composition of 66% clay and 28% silt. Chemical analysis showed a composition of 65% Kaolin, 28% Quartz and 5% Muscovite. The specific gravity