scholarly journals Revealing the dependence of the physiochemical and mechanical properties of cement composites on graphene oxide concentration

RSC Advances ◽  
2017 ◽  
Vol 7 (87) ◽  
pp. 55148-55156 ◽  
Author(s):  
Aliakbar Gholampour ◽  
Meisam Valizadeh Kiamahalleh ◽  
Diana N. H. Tran ◽  
Togay Ozbakkaloglu ◽  
Dusan Losic

This paper presents a comprehensive study to evaluate the influence of graphene oxide (GO) concentration on the physiochemical and mechanical properties of cement mortar composites.

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Fakhim Babak ◽  
Hassani Abolfazl ◽  
Rashidi Alimorad ◽  
Ghodousi Parviz

We investigate the performance of graphene oxide (GO) in improving mechanical properties of cement composites. A polycarboxylate superplasticizer was used 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.


Materials ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 3753 ◽  
Author(s):  
Yahui Wang ◽  
Jiawen Yang ◽  
Dong Ouyang

The effects of the water–binder ratio and different graphene oxide (GO) sizes on the mechanical properties of GO-cement composites were systematically studied by preparing GO-cement mortars. The scanning electron microscopy observation (SEM) of the surface and fracture surface of cement pastes was carried out to study the morphology of cement hydration crystals in GO-cement systems under different space conditions. It was found that GO nanosheets significantly improved the compressive, flexural, and tensile strengths of cement mortars. When the dosage of GO nanosheets was 0.03% by weight of cement, the compressive, flexural, and tensile strengths at 28 days increased by 21.37%, 39.62%, and 53.77%, respectively, but GO was not found to be able to regulate the formation of flower-like cement hydration crystals. It was only shown that the growth space had an important influence on the morphology of hydrates. A possible working mechanism was proposed by which GO nanosheets prevented the expansion of microcracks in the cement pastes via a shield effect, thus enhancing the strength and toughness of the cement composites.


2020 ◽  
Vol 250 ◽  
pp. 118832 ◽  
Author(s):  
Meisam Valizadeh Kiamahalleh ◽  
Aliakbar Gholampour ◽  
Diana N.H. Tran ◽  
Togay Ozbakkaloglu ◽  
Dusan Losic

2017 ◽  
Vol 26 (1) ◽  
pp. 096369351702600
Author(s):  
BLP Dheeraj Swamy ◽  
Vaibhav Raghavan ◽  
K Srinivas ◽  
K Narasinga Rao ◽  
Mahadevan Lakshmanan ◽  
...  

This study focuses on the utilization of highly densified materials in cementitious composites with objectives of improving the mechanical performance and minimizing the number and size of defects. Due to their excellent mechanical properties, carbon nanotubes (CNTs) are now viewed as potential candidate for reinforcement in cement composites. The present paper reports the use of carbon nanotubes (CNTs) as reinforcement to improve the mechanical properties of portland cement paste and creating multifunctional concrete. In order to increase the bonding, and strength, a material with intermediate fineness, highly densified silica fumes, was also utilized. The densified silica fumes along with CNT are added to cement mortar in various proportions. Small-scale specimens were prepared to measure the mechanical properties as a function of nanotube concentration and distribution. Furthermore, properties like shrinkage, permeability and alkalinity of the resultant composite were also investigated. The study addresses the significance of CNT as an additive to the enhancement of properties of cement composite.


Nanomaterials ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 113 ◽  
Author(s):  
Hongfang Sun ◽  
Li Ling ◽  
Zhili Ren ◽  
Shazim Ali Memon ◽  
Feng Xing

This paper evaluated the effect of graphene oxide/graphene (GO/GR) hybrid on mechanical properties of cement mortar. The underlying mechanism was also investigated. In the GO/GR hybrid, GO was expected to act as a dispersant for GR while GR was used as reinforcement in mortar due to its excellent mechanical properties. For the mortar specimen, flexural and compressive strength were measured at varied GO to GR ratios of 1:0, 3:1, 1:1, 1:3, and 0:1 by keeping the total amount of GO and GR constant. The underlying mechanism was investigated through the dispersibility of GR, heat releasing characteristics during hydration, and porosity of mortar. The results showed that GO/GR hybrid significantly enhanced the flexural and compressive strength of cement mortars. The flexural strength reached maximum at GO:GR = 1:1, where the enhancement level was up to 23.04% (28 days) when compared to mortar prepared with only GO, and up to 15.63% (7 days) when compared to mortar prepared with only GR. In terms of compressive strength, the enhancement level for GO:GR = 3:1 was up to 21.10% (3 days) when compared with that of mortar incorporating GO only. The enhancement in compressive strength with mortar at GO:GR = 1:1 was up to 14.69% (7-day) when compared with mortar incorporating GR only. In addition to dispersibility, the compressive strength was also influenced by other factors, such as the degree of hydration, porosity, and pore size distribution of mortar, which made the mortars perform best at different ages.


2013 ◽  
Vol 49 ◽  
pp. 121-127 ◽  
Author(s):  
Shenghua Lv ◽  
Yujuan Ma ◽  
Chaochao Qiu ◽  
Ting Sun ◽  
Jingjing Liu ◽  
...  

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