Graphene-Enhanced Cement Mortar as a Repair Material for Concrete: Effect on Compressive Strength

Abstract

Cracks could develop and propagate into the full depth of concrete, if disregarded. Repair of the concrete can be performed by filling the cracks with cement mortar as a repair material. With the advent of graphene, which is a nano-material that possesses remarkable properties, a graphene‑enhanced nano-cement composite can potentially be employed as a repair material for concrete. Effect of incorporating graphene nanoplatelets (GnP) into cement mortar at contents of 0.00, 0.02, 0.04, 0.06, 0.08 and 0.1 wt.% of GnP to total weight of cement on repair performance was investigated. Cylindrical concrete samples with a strength grade of 35 MPa were prepared and cured for 3, 7 and 28 days. The samples were cracked by subjecting them to compressive loading until failure. The mortar was then employed to repair the cracked samples. Compressive strengths of the sample before and after repair were recorded. Findings reveal that the graphene‑enhanced cement mortar was more aggressive in retaining as much compressive strength of the concrete as possible after crack and repair than plain cement mortar. However, concrete that was repaired with graphene-enhanced mortar was not able to retain the initial compressive strength. Nonetheless, the GnP content of 0.02 wt.% resulted in the best repair performance.