The goal of this paper is the use of a fly ash with high unburned carbon which generally has lower demand in the market because, according to ASTM C618, it cannot be used in Portland cement concrete. Alkali-activated cements (AACs) based on this industrial by-product were prepared using granulated blast furnace slag (GBFS) and lime (L) as calcium sources. The AACs were used for A-4 type soil improvement. The unconfined compressive strength, flexure strength, and durability (volume change and mass loss) of the soil treated were evaluated. The results showed that under soaked conditions the compressive strength increased up to 119.4% at 7 days of curing and 78.6% at 28 days of curing. Additionally, the mass loss percentage after twelve (12) wetting and drying cycles was less than that allowed by Colombian specifications for stabilized soil. This demonstrated that it is possible to use this type of fly ash as an environmentally sustainable alternative to replace Portland cement as soil stabilizer in applications for road construction. The proposed solutions are thus considered competitive with current chemical stabilization techniques. However, further studies on the long-term performance of AACs stabilized soils, and the cost of applying AACs in soil stabilization are worth being conducted.

本文的目标是使用未燃碳含量高的粉煤灰，由于市场对ASTM C618的要求不高，因此其需求量较低，因为它不能用于硅酸盐水泥混凝土中。基于工业副产品的碱活化水泥（AAC）是使用高炉矿渣（GBFS）和石灰（L）作为钙源制备的。AAC用于A-4型土壤改良。评价了被处理土壤的无侧限抗压强度，挠曲强度和耐久性（体积变化和质量损失）。结果表明，在浸泡条件下，固化7天的抗压强度提高到119.4％，固化28天的抗压强度提高到78.6％。此外，经过十二（12）次润湿和干燥循环后，质量损失百分比小于哥伦比亚关于稳定土壤的规格所允许的质量损失百分比。这表明在公路建设中可以使用这种类型的粉煤灰作为环境可持续的替代品来代替波特兰水泥作为土壤稳定剂。因此，提出的解决方案被认为与当前的化学稳定技术具有竞争力。然而，值得进一步研究AAC稳定土壤的长期性能，以及在土壤稳定中使用AAC的成本。