The effect of graphene nanoplatelet addition on the mechanical, durability and self-healing properties of engineered cementitious composites

Abstract

Nanomaterial usage is an effective method to enhance the mechanical and durability properties of cementitious materials. Graphene Nanoplatelets (GNPs) are cost-efficient graphene-based nanomaterials that can exhibit graphene-like features. Although GNPs have been found to improve mechanical and durability properties, their effect on the self-healing behavior of cementitious materials, particularly Engineered Cementitious Composites (ECC), has not been examined in the literature studies. Therefore, this study aims to investigate the effects of GNP addition on mechanical, durability and self-healing behavior of ECC. During the study, the mechanical, durability, and self-healing characteristics of ECC with and without GNP were observed by using various mechanical and non-destructive test methods. Compression test, four-point bending test, resonance frequency test, ultrasonic pulse velocity test, sorptivity test, electrical impedance test and microscopic inspection were conducted. According to the test results, 0.05% GNP addition increased the compressive strength of ECC specimens. With the effect of GNP, first cracking strength, ultimate flexural strength and deformation values increased both for virgin and preloaded ECC specimens. The preloaded specimens with GNP performed similarly to virgin specimens under bending. The cracks of preloaded GNP specimens were either closed completely or extensively compared to control specimens. The crack numbers of GNP specimens after failure were also greater than that of control specimens. Accordingly, the flexural and self-healing behavior of the specimens improved with GNP addition. The effect of improvement by GNP addition was also evident in nondestructive tests. A considerable increment occurred in electrical resistance with GNP addition.