Fabrication of graphene oxide/fiber reinforced polymer cement mortar with remarkable repair and bonding properties

It is cost-effective and low-carbon emission using high performance mortar to repair and protect damaged structures. Here, graphene oxide (GO)/steel fiber (SF) reinforced ethylene vinyl acetate (EVA) polymer compound sulfoaluminate cement repair mortar (GOCRM) was directly prepared by water-reducer sonication dispersion and subsequent shear mix method. The workability, mechanical properties, and durability of GOCRM were systematically investigated along with microstructure and micro/nano enhancement mechanism evaluation. The flowability, initial/final setting time, 1 day/28 days flexural, 1 day/28 days compressive, interfacial bonding strength (fb), 90 days drying shrinkage, 3 days water absorption rate, contact angle and migration coefficient of chloride ion of GOCRM at 0.03% GO dosage reach 192.0 mm, 35 min/53 min, 8 MPa/19.9 MPa, 21.3 MPa/79.3 MPa, 4.93 MPa, 1.051x10-4, 0.1%, 80.96 & DEG; and 2.322x10-13 m2/s, respectively. Microscopic morphology, Fourier transform infrared spectroscopy, and X-ray diffraction spectra of mortars with varied curing ages demonstrate that sulfoaluminate cement, EVA, GO incorporation can improve the microstructure in interiors and at interfaces of mortars by filling micro-pores between products and promoting hydration degree. Accordingly, tighter bonding surface, higher fb and superior bond durability between GOCRM and the old substrate are achieved. These indicate that GOCRM can advantageously serve as high-performance repair mortar with superior fast repair capability, and long-term repair stability. & COPY; 2023 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).