ACI 549.4R-20

Fabric-reinforced cementitious matrix (FRCM) and steel-reinforced grout (SRG) systems for rehabilitation and strengthening concrete structures is an alternative to traditional techniques such as fiber-reinforced polymers (FRPs), steel plate bonding, section enlargement, and external post-tensioning. An FRCM/SRG is a composite material consisting of one or more layers of inorganic matrix reinforced with dry fibers in the form of open mesh or fabric. The inorganic matrixes are typically cement-based, lime-based, or geopolymer. When adhered to concrete structural members, they form an FRCM/SRG system that acts as supplemental, externally bonded reinforcement. This guide addresses the history and use of FRCM and SRG systems rehabilitation and strengthening, their unique material properties, and recommendations on their design, construction, and inspection. Guidelines are based on experimental research, analytical work, and field applications.