Self-consolidating earth concrete (SCEC) addresses the long construction process of conventional earthen constructions and their structural limitations, while further efforts are needed to enhance its sustainability. This study explores the development of a kaolinite-based self-consolidating earth paste (SCEP) due to their blended powder system, incorporating raw and treated (calcined and ground-calcined) kaolinite under various activation techniques, such as water hydration, sodium hexametaphosphate (NaHMP), and sodium hydroxide (NaOH) activation. The synergistic effect of calcination and mechanosynthesis on rheological, mechanical, structural, and microstructural properties of SCEP were investigated. Mechanically treated kaolinite increased yield stress, plastic viscosity, storage modulus evolution, and build-up index, while delayed the strength development compared to the calcined kaolinite samples. Among the investigated activators, NaOH resulted in more promising structural build-up, storage modulus, and compressive strength development. These findings were elaborated with X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), calorimetry, thermogravimetric analysis (TGA), and scanning electron microscopy (SEM).

Earth concrete is composed of fine particles which make them very sensitive to humidity and affects their longterm durability. In this study, the effect of wetting/drying cycles on earth concrete according to ASTM D559 was studied by measuring the weight loss, pH, and Electrical Conductivity (EC). The effect of different percentages of flax fibers was investigated. The residual properties of reference specimens and earth concrete specimens subjected to wetting/drying cycles were evaluated by conducting compressive tests at the end of the 25 cycles. Ultrasound, Acoustic Emission (AE), and Digital Image Correlation (DIC) techniques were applied to estimate the concrete progressive deterioration during and at the end of the 25 wetting/drying cycles. The results showed that earth concrete degradation begins during the first cycle with visible cracks on the surface of the specimens. The mechanical tests showed a considerable loss of earth concrete mechanical properties after 25 cycles. The ultrasonic test showed that the degradation rate was more important for specimens without flax fibers. The cumulative acoustic activity was effectively used to assess the different damage progression phases and crack propagation. The signal parameters (energy, amplitude, etc.) evolution indicates premature damage for earth concrete specimens subjected to wetting drying cycles.