Dynamic Mechanical Properties and Microstructure of Graphene Oxide Nanosheets Reinforced Cement Composites.

Wu-Jian Long,Hongyan Ma,Jing-Jie Wei,Feng Xing

doi:10.3390/nano7120407

Wu-Jian Long, Hongyan Ma + Show 2 more

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https://doi.org/10.3390/nano7120407

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Abstract

This paper presents an experimental investigation on the effect of uniformly dispersed graphene oxide (GO) nanosheets on dynamic mechanical properties of cement based composites prepared with recycled fine aggregate (RFA). Three different amounts of GO, 0.05%, 0.10%, and 0.20% in mass of cement, were used in the experiments. The visual inspections of GO nanosheets were also carried out after ultrasonication by transmission electron microscope (TEM) atomic force microscope (AFM), and Raman to characterize the dispersion effect of graphite oxide. Dynamic mechanical analyzer test showed that the maximum increased amount of loss factor and storage modulus, energy absorption was 125%, 53%, and 200% when compared to the control sample, respectively. The flexural and compressive strengths of GO-mortar increased up to 22% to 41.3% and 16.2% to 16.4% with 0.20 wt % GO at 14 and 28 days, respectively. However the workability decreased by 7.5% to 18.8% with 0.05% and 0.2% GO addition. Microstructural analysis with environmental scanning electron microscopy (ESEM)/backscattered mode (BSEM) showed that the GO-cement composites had a much denser structure and better crystallized hydration products, meanwhile mercury intrusion porosimetry (MIP) testing and image analysis demonstrated that the incorporation of GO in the composites can help in refining capillary pore structure and reducing the air voids content.

Highlights

The rapid economic growth in China has encouraged an enormous number of construction activities
The motivation of this paper is to investigate the potential of graphene oxide (GO) in improving the dynamic mechanical properties of recycled fine aggregate (RFA) composites
The addition of GO decreased the workability of cement paste and RFA mortar at different amounts of 0.05%, 0.1%, 0.2% by mass of cement, respectively

Summary

Introduction

The rapid economic growth in China has encouraged an enormous number of construction activities. A number of publications on the use of RFA in mortar or concrete concluded that strength and durability decreased with the increase of the replacement ratio of RFA [4,5,6,7]. The porosity of mortar containing recycled fine aggregate is normally larger than that of the mortar made with natural sand [9,10]. This is attributed to the large surface area and poor surface quality of the recycled fine aggregate, which create a weak interface transition zone (ITZ), and decreases bonding between the matrix and the fine aggregate [11,12]

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