Investigation of the Feasibility of Stabilizing Tropical Soils Using an In Situ Synthesized One‐Part Geopolymer Binder

ABSTRACT One of the prerequisites for achieving sustainable development is the design and production of materials that focus on energy‐saving processes as well as environmentally and eco‐friendly use of local raw materials, with engineering properties suitable for building constructions. This work offers an alternative way of enhancing the reactivity of tropical clayey soils for civil engineering purposes. This overcame the concerns raised over the use of the traditional alkaline binder for stabilization of soil: calcination of aluminosilicate materials and the harm related to managing and blending highly eroding and typically viscous alkali solutions. Numerous analytical techniques, including X‐ray diffraction, infrared Fourier transformation (FT‐IR), compressive strength (UCS), thermal gravimetric, and microstructural analysis, were used to assess the features of the produced stabilized clayey soils. The results demonstrated that the co‐grinding process applied to blending mixed precursors and activating powders effectively integrated alkali cations into the precursor structure, ultimately resulting in the formation of a solid alternative binder. Moreover, at 28 days, the amorphous geopolymer phases, such as sodalite and hydroxysodalite, are found alongside primarily crystalline phases of clayey soils, such as nontronite, natrolite, kaolinite, and quartz. The in situ produced NASH‐gel binder participated in closing spaces and voids, resulting in the densification of the stabilized clayey materials. The high values of compressive strength of 2.6 MPa were achieved and were at least three times as high as those made with unmilled soils. This eventually would add value to tropical earth‐based materials through efficient use in the production of sustainable materials with excellent engineering performance.