Abolfazl Hassani - Professor, Department of Civil and Environmental Engineering, Tarbiat Modares University, Tehran, Iran
Babak Fakhim - Ph. D. Candidate, Department of Civil and Environmental Engineering, Tarbiat Modares University, Tehran, Iran
Alimorad Rashidi - Associate Professor, Nanotechnology Research Center, Research Institute of Petroleum Industry, Tehran, Iran
Parviz Ghoddousi - Assistant Professor, Department of Civil Engineering, Iran University of Science and Technology, Tehran

Herein, the performance of graphene oxide (GO) in improving mechanical properties and subsequently reducing the permeability of cement composites used in concrete pavement, is studied. A polycarboxylate superplasticizer wasused to improve the dispersion of GO flakes in the cement. The mechanical strength of graphene-cement nanocomposites containing 0.1–2 wt% GO and 0.5 wt% superplasticizer was measured and compared with that of cement prepared without GO. We found that the tensile strength of the cement mortar increased with GO content, reaching 1.5%, a 48% increase in tensile strength. Ultra high-resolution field emission scanning electron microscopy (FE-SEM) used to observe the fracture surface of samples containing 1.5 wt% GO indicated that the nano GO flakes were well dispersed in the matrix, and no aggregates were observed. FE-SEM observation also revealed good bonding between the GO surfaces and the surrounding cement matrix. In addition, XRD diffraction data showed growth of the calcium silicate hydrates (C-S-H) gels in GO cement mortar compared with the normal cement mortar. Growths of the calcium silicate hydrates (C-S-H) gels causes reduce in permeability and consequently improvement in durability of the cement composite.

Cement, nanocomposite, graphene oxide, mechanical properties, tensile strength. Pavement