The rapid growth of the construction industry, driven by factors such as urbanisation and infrastructure development, has led to significant challenges. One of the major concerns is the depletion of natural aggregates, resulting in adverse impacts on infrastructure, heightened costs, and the environment. To counteract these issues, using construction and demolition waste (CDW) materials in road construction has emerged as a viable solution. Fly ash (FA), a readily available byproduct, holds immense potential for environmentally beneficial applications. By effectively utilising FA, significant positive impacts can be achieved. A potential approach to make sustainable pavement bases involves mixing liquid alkali activators (LAA), such as NaOH and Na2SiO3, in a 50:50 ratio with FA. This combination improves cementation, strength, and stiffness properties. In pursuit of this objective, this study aims to harness a larger proportion of CDW in pavement base courses, replacing traditional natural aggregates (NA). The goal is to establish a foundation that aligns with sustainability principles. However, ensuring the reliability of the design process and the feasibility of using a substantial amount of CDW requires addressing a range of concerns. To achieve this, various basic and engineering tests have been executed on blends of alkali-activated FA-treated CDW and NA mixes. The CDW material was varied between 90 and 60% in replacement of NA from the mix design. Based on the unconfined compressive strength tests, a 70% replacement of NA with CWD was found optimum.