High porosity in carbon or polyester filaments weakens the crosslinked resin bond, leading to premature fiber pull-out under stress.

High pH environments in wet concrete cause chemical erosion of glass yarns and resin matrices, reducing long-term structural integrity.

Low breaking strain and improper filament dimensions in glass-resin composites result in brittle failure when concrete undergoes flexural loading.

Alternative mineral filaments exhibit poor interfacial adhesion with crosslinked resins compared to standard glass, causing internal delamination during curing.