How Can Graphene Oxide Improve the Properties of Cement?

In a recent study published in the journal Materials, researchers from China studied the improvement in properties of concrete due to the addition of graphene oxide (GO).

Study: Efficient Use of Graphene Oxide in Layered Cement Mortar. Image Credit: Daniel Ramirez-Gonzalez/Shutterstock.com

Concrete and Nanomaterials

Concrete is the most widely used construction material due to its high compressive strength and low cost. The main limitation of concrete is that it is a brittle material with low tensile strength and poor corrosion resistance. Furthermore, when Portland cement is manufactured, a significant amount of CO2 is released. Due to this, researchers worldwide are trying to improve concrete's durability and mechanical properties. 

Geometry of layered cement mortar specimens.

Geometry of layered cement mortar specimens. Image Credit: Liu, S et al., Materials

The advancement of nanomaterials has provided valuable opportunities to improve the properties of concrete in recent years. Several studies have demonstrated that nanomaterials like nano-silica, carbon nanotubes, and GO improve the strength, toughness, and durability of cement composites.

The present study analyzed the properties of layered cement mortar samples with a graded distribution of GO.

Methodology

The materials used by the researchers were ordinary Portland cement (OPC) grade, standard sand, and graphene. The cement and sand were used to prepare the concrete, and the graphene was used to prepare the GO suspension. The method used was wet-on-wet layering fabrication, during which a fresh cement mortar layer containing GO was cast on top of a previously casted cement mortar layer.

The researchers prepared two varieties of cement mortar samples: the first was plain cement mortar with no GO solution, and the second was GO-incorporated cement mortar. The water-to-cement and sand-to-cement mass ratios for both samples were 2.0 and 0.4, respectively. Additionally, to ensure that the samples had comparable workability, the amount of superplasticizer was adjusted, and a mini-slump test was used to determine workability.

The mortar mixture was cast into molds and mixed on a vibration table to ensure high compaction during sample development. The molds were enclosed with polyethylene sheets, and further, the samples were molded and treated in a saturated limewater bath before testing to prevent water evaporation. Successive layers of fresh cement mortar and cement mortar with GO were cast to prepare the layered cement mortar beams with the graded distribution of GO.

Four cut locations of each sample.

Four cut locations of each sample. Image Credit: Liu, S et al., Materials

Results

The plain cement mortar sample's scanning electron microscope (SEM) images showed a loose and porous microstructure. The SEM images of the GO-added cement mortar sample revealed a denser structure. The improvement in the GO-incorporated mortar cement mechanical properties resulted from changes in the microstructure of cement. 

The flexural strength results revealed that the strength increased to a maximum and then decreased as the delay time increased. Additionally, the strength was not dependent on the thickness of the cement layer. The highest flexural strength was found with a GO layer thickness of 12 mm and a delay time of 50 minutes. The maximum flexural strength was dependent on the delay time for the samples with different GO layer thicknesses.

The study of images of the layered cement mortar beams after flexural failure revealed a significant difference in crack development between the GO layered and plain cement mortar beams. In the plain cement mortar, the beam crack was completely vertical and had a relatively flat fracture surface.

On the layered cement mortar beam containing GO, inclined and tortuous cracks were observed. Additionally, compared to the control sample, the properties of the layered cement mortar beams did not change when the GO was added only in the tensile region of the samples. However, the interface developed between the layers of the samples considerably influenced the mechanical properties. Furthermore, the interface adhesion was also affected by the delay time and amount of GO in the samples.

The rapid chloride migration (RCM) tests revealed that a small quantity of GO could significantly reduce chloride ingress, and when the amount of the GO was enhanced, the RCM effect also increased. The reason for increment was that GO nanosheets' presence increased the cement matrix's tortuosity, which immobilized water and chloride ion migration through chemical bonding.

Crack development of samples: (a) L8T50, (b) L12T50, (c) L16T50, (d) M, and (e) L12T300. Fractured surfaces of samples: (a’) L8T50, (b’) L12T50, (c’) L16T50.

Crack development of samples: (a) L8T50, (b) L12T50, (c) L16T50, (d) M, and (e) L12T300. Fractured surfaces of samples: (a’) L8T50, (b’) L12T50, (c’) L16T50. Image Credit: Liu, S et al., Materials

Conclusions

The researchers developed functionally graded cement mortar beams using successive layers of mortar cement and GO-incorporated mortar cement. The effects of the thickness of each GO-incorporated cement mortar layer and the delay time on the mechanical and durability properties were investigated.

The study demonstrated that the nanomaterial GO could be used in parts of cementitious composites to improve the mechanical properties. This method provides a novel approach to use nanomaterials effectively in cement-based materials. Future research should study the ways to improve interfacial adhesion between GO-incorporated cement mortar layers and cement mortar layers without GO.

Source

Liu, S.; Lu, F.; Chen, Y.; Dong, B.; Du, H.; Li, X. Efficient Use of Graphene Oxide in Layered Cement Mortar. Materials 2022, 15, 2181. https://www.mdpi.com/1996-1944/15/6/2181

Disclaimer: The views expressed here are those of the author expressed in their private capacity and do not necessarily represent the views of AZoM.com Limited T/A AZoNetwork the owner and operator of this website. This disclaimer forms part of the Terms and conditions of use of this website.

Chinmay Saraf

Written by

Chinmay Saraf

Chinmay Saraf is a science writer based in Indore, India. His academic background is in mechanical engineering, and he has extensive experience in fused deposition-based additive manufacturing. His research focuses on post-processing methods for fused deposition modeling to improve mechanical and electrical properties of 3D printed parts. He has also worked on composite 3D printing, bioprinting, and food printing technologies. Chinmay holds an M.Tech. in computer-aided design and computer-aided manufacturing and is passionate about 3D printing, new product development, material science, and sustainability. He also has a keen interest in "Frugal Designs" to improve the existing engineering systems.  

Citations

Please use one of the following formats to cite this article in your essay, paper or report:

  • APA

    Saraf, Chinmay. (2022, March 18). How Can Graphene Oxide Improve the Properties of Cement?. AZoM. Retrieved on July 05, 2022 from https://www.azom.com/news.aspx?newsID=58569.

  • MLA

    Saraf, Chinmay. "How Can Graphene Oxide Improve the Properties of Cement?". AZoM. 05 July 2022. <https://www.azom.com/news.aspx?newsID=58569>.

  • Chicago

    Saraf, Chinmay. "How Can Graphene Oxide Improve the Properties of Cement?". AZoM. https://www.azom.com/news.aspx?newsID=58569. (accessed July 05, 2022).

  • Harvard

    Saraf, Chinmay. 2022. How Can Graphene Oxide Improve the Properties of Cement?. AZoM, viewed 05 July 2022, https://www.azom.com/news.aspx?newsID=58569.

Tell Us What You Think

Do you have a review, update or anything you would like to add to this news story?

Leave your feedback
Your comment type
Submit