Mechanical Behavior of a Granular Soil Stabilized with Alkali-Activated Waste

Abstract

The lack of bearing capacity of geotechnical materials is a recurrent problem that can be solved through chemical admixtures and densification methods. However, traditional materials/techniques are normally associated with energy-intensive processes and the extraction of natural resources and gaseous emissions. As a result, interest in more ecologically friendly solutions is rising. This paper evaluated the influence of several factors on the mechanical behavior of granular soil stabilized with an alternative alkali-activated cement produced from ceramic waste and carbide lime. Mixtures were tested for unconfined compressive strength, stiffness, durability, and strength parameters on simple shear equipment. The porosity/binder content index was applied to correlate all outcomes. Results showed that a lower silica modulus (SiO2/Na2O) resulted in lower strength and stiffness due to excessive alkalis presence; Lower silica modulus, however, also led to a smaller loss of mass under durability circumstances, indicating that the test conditions diluted any excessive alkalis. It has been demonstrated that the porosity/binder index is a useful tool for predicting mechanical behavior in terms of strength, stiffness, and durability. Finally, the monotonic shear response showed that the inclusion of the alkali-activated cement positively influenced the internal friction angle of the material and the cohesion intercept when compared to the natural granular soil.