Microbial Deterioration Potential and Mitigation Strategies in Blended Cement Structures: A Review

Microbial‐induced deterioration (MID) is a threat to the durability of cement‐based materials (CBMs) particularly in sewer and wastewater systems. Whereas blended cements incorporating supplementary cementitious materials (SCMs) offer environmental benefits such as reduced carbon (IV) oxide (CO 2 ) emissions and enhanced mechanical performance, their long‐term resilience under microbial attack remains uncertain. The present systematic review synthesizes peer‐reviewed literature from 2019 to 2026, selected from Scopus, Web of Science, ScienceDirect, and Wiley Online Library using rigorously defined search terms and stringent inclusion and exclusion criteria. The subsequent analysis divides the results into microbial mechanisms, the performance of the materials, and mitigation strategies, which can help create a comparative analysis between SCMs‐rich systems and next‐generation binders, in particular limestone‐calcined clay cement (LC 3 ). Experimental evidence shows that the mechanical properties of cementitious building materials are significantly reduced by microbial exposure. For example, OPC mortars exposed to Thiobacillus thioparus showed a 34% decrease in compressive strength after 90 days, while exposure to Acidithiobacillus thiooxidans showed strength losses of 19.9% in PPC and 39.8% in OPC mortars. Moreover, compressive strength reductions of up to 96% and dimensional changes of 11% in OPC specimens have been observed after prolonged exposure of these materials to sulfur‐oxidizing bacterial cultures. Such findings highlight the importance of considering microbial activity in durability assessments of concrete structures. Incorporation of SCMs can reduce these adverse effects. Nanophase modified fly ash (FA) concretes, for instance, have negligible pH reduction and dimensional variation whereas calcium aluminate cement (CAC) mortars maintain a higher strength due to their inherent bacteriostatic properties. These observations suggest that SCMs not only alter the microstructure but also provide a degree of biochemical resilience against microbial attack. Though LC 3 show great potential for microbial attack resistance due its alumina‐rich hydrates and reduced portlandite content, there are still uncertainties about their buffering capacity and stability of carbonate phases in the presence of aggressive microbial environments. Mitigation strategies, such as coatings, biocidal additives and microbial‐induced mineralization (MIM) have been evaluated with varying levels of efficacy, but their long term mechanical, microstructural as well as environmental compatibility with the SCMs and LC 3 formulations are underexplored. This review identifies critical gaps in standardized microbial durability testing, LC 3 performance evaluation, and sustainability assessments of mitigation strategies. Addressing these gaps is essential for developing bio‐resilient, environmentally sustainable cementitious materials that support infrastructure resilience and align with the global sustainable development goals (SDGs).