A Generic Framework of Unifying Industrial By-products for Soil Stabilization

This paper presents a newly proposed generic framework for unifying different industrial by-products (IBPs) as composite binders to potentially replace ordinary Portland cement (OPC) for soft clay stabilization. The concepts of three chemical moduli (TCM) and strength activity index (SAI) are used to determine the fractions of different IBPs, and the final design mix is further tuned by adding gypsum for additional strength gain contributed by density due to ettringite formation. As a case study, a coastal soft clay was stabilized by different IBPs and gypsum using the new generic framework. Results show that the highest unconfined compression strengths of the IBPs stabilized clay cured for 7, 28, and 60 days reach 0.75, 1.21, and 1.39 MPa, respectively, which are even higher than those of the OPC-stabilized counterparts, suggesting the possibility of using IBPs to substitute OPC. Moreover, the additive gypsum plays a beneficial role for more strength gain due to the formation and volumetric expansion of ettringite. The implementation strategy for the new framework is recommended, and its practical implications for soil stabilization are discussed in terms of IBPs recycling and reuse, environmental sustainability, and economic benefits.