Cemented paste backfill (CPB) is an innovative cementitious construction material widely used in modern underground mining to provide ground support while enabling the sustainable management of mine waste (tailings). However, the formation of cracks within CPB structures remains a persistent challenge that threaten long-term mechanical stability and durability. Recent studies increasingly demonstrate that CPB possesses a promising self-healing capacity, allowing recovery of mechanical strength and permeability without external intervention. This review presents a comprehensive and critical synthesis of current advances in the understanding of self-healing behaviour in CPB, integrating experimental evidence with fundamental concepts established for conventional cementitious materials. The mechanisms governing crack formation in CPB are systematically examined, followed by an in-depth review of autogenous and autonomous healing pathways, with particular emphasis on continued hydration, carbonation, and mineral precipitation processes. The influences of key governing parameters, including curing age, crack geometry, temperature, drainage conditions, stress state, and chemical environment, are comprehensively assessed. Special attention is given to the role of mineral additives (e.g., blast furnace slag and fly ash) and emerging biological approaches based on microbially induced calcite precipitation, while identifying important knowledge gaps related to silica fume and conventional chemical admixtures. Experimental techniques employed to characterize CPB self-healing are synthesized, encompassing crack closure, mechanical strength and permeability recovery, microstructural imaging, and chemical and mineralogical analyses. By consolidating fragmented knowledge across disciplines, this review clarifies the mechanisms controlling CPB self-healing, identifies limitations of existing laboratory-scale studies, and outlines priorities for Multiphysics modeling, field-scale validation, and the development of hybrid self-healing systems. This paper establishes self-healing as a quantifiable and design-relevant property of CPB, supporting the advancement of more resilient, durable, and low-carbon underground backfill systems. • CPB shows strong autogenous self-healing via hydration, carbonation, and mineral precipitation • THMC conditions and crack geometry control strength and permeability recovery • Multi-scale techniques quantify crack closure and performance restoration • Self-healing enables durable and low-carbon backfill systems • Mechanistic framework links microstructural healing to engineering performance
Fall et al. (2026) studied this question.