Interfacial bonding of carbon-coated glass fiber reinforced cement

Interfacial mechanical bonding strength and frictional stress of carbon-coated S-glass fiber reinforced cement were characterized by a fiber push-out technique. The push-out experiments were conducted on model composites, where the S-glass monofilaments with/without carbon coating were unidirectionally embedded in the ordinary Portland cement (OPC). The composite with a carbon interface exhibits a weaker interfacial bonding strength (14 MPa) and lower frictional stress (10 MPa) than that (37 MPa and 28 MPa, respectively) of the composite without a carbon interface. SEM observations indicated that the filament without carbon coating was significantly attacked and strongly bonded onto the matrix, while the filament with carbon coating retained intact under the same curing conditions. The studies suggested that the carbon coating provides glass fiber with significantly improved corrosion resistance to alkali in the cement environment.