Supplementary Cementitious Materials (SCMs) in Concrete Performance Reviewing Material Behavior to Advance Uncertainty Analysis in Design

Supplementary cementitious materials (SCMs) stand at the forefront of sustainable concrete development by delivering both environmental benefits and improved performance. The purpose of this review is to evaluate the mechanical properties, durability, and environmental impact of the principal supplementary cementitious materials, including agricultural ashes, natural pozzolans, industrial by-products, and the latest pioneer waste-based recycled materials. From the integration of data from multiple past studies, it is evident that SCM has significantly improved resistance to chlorides, shrinkage, thaw cycles, and increased compressive and flexural strength over a very long term, as well as reduced permeability, among other durability aspects. These beneficial performances are linked to natural pozzolanic reactions, microfillers, and enhanced pore structure refinement brought about by increased levels of calcium silicate hydrate C-S-H gel gelation. Reduced early age strength, workability, and variability remain concerns, especially with the more recent SCMs from various generated wastes. This review emphasizes also the role of performance metrics, research data integration, and meta-analysis in enhancing decisiveness under challenging circumstances. Glass powder materials, ceramic wastes, and agricultural ashes are examples of innovative SCMs that hold tremendous promise for near-future applications, provided there is further refinement of processing methods. The conclusions of this study confirm that SCM significantly contributes to material recyclability, durability performance enhancement, and carbon decarbonization. In this way, this concept introduces SCMs as a key innovation route to ensuring high-performance, greener, and sustainable concreting technology.