Effect of different water-reducing agents on mechanical properties and microstructure of graphite oxide-blended cement mortar.

Graphene oxide (GO) is easily precipitated n high-calcium and high-alkaline cement pastes. In this paper, the dispersion effects of different water-reducing, such as different polycarboxylates (PC1, PC2, PC3), sulfamic acid (A1), and aliphaic (B1), on GO were studied, and the effect different water-reducing on compressive strength, flexural strength and Hudity of GO compounded cement mortar was investigated. The results showed that the mechanical strength of the cement mortar specimens with GO add-on was the largest when the GO content was 0.03%. The compressive strength and lexural strength of the cement mortar sample with GO add-on were increased by 45.26% and 50.66% compared with the blank samples. 28 d compressive strength and flexural strength also increased by 27.24% and 9.3% compared with the blank samples. In terms of fluidity, compared with the blank specimens, except for PC1, several other water reducing agents could make the flow of GO--mixed mortar almost unchanged. The X-ray diffraction (XRD) and scanning electron microscopy (SEM) results of the hardened cement showed that the add-on of PC2 could effectively promote the growth of Aft crystals of the really cement hydration product, and greatly improved the really flexural and compressive strength of the cement mortar. The results of fared spectroscopy (FT--R) and Raman spectroscopy(Raman) showed that the water-reducing PC2 could make GO more disperse n the simulated cement slurry, and the epoxy group in GO could participate in the cement hydration reaction, making a strong interface force between GO and cement hydration products. [ABSTRACT FROM AUTHOR]