Engineers Analyze Graphene Oxide in Concrete

TUESDAY, DECEMBER 12, 2023


A team from RMIT University and the University of Melbourne is reportedly the first to investigate the effects of graphene oxide in 3D printed concrete, with the goal of creating potential “smart” walls that can monitor cracks.

The study was recently published in the journal Additive Manufacturing Letters.

About the Research

According to a release from RMIT, engineers found the addition of graphene oxide, a nanomaterial commonly used in batteries and electronic gadgets, gave concrete electrical conductivity. It also increased the strength of concrete by up to 10%.

Research supervisor and RMIT associate professor Jonathan Tran said this concrete had the potential to create “smart” buildings where walls can act as sensors to detect and monitor small cracks.

Current detection methods for large cracks in structures, like ultrasonic or acoustic sensors, are non-destructive and widely used in construction, the university explains; however, detecting smaller cracks early is still considered a challenge.  

“The equipment for these methods is often bulky, making it difficult to regularly use for monitoring very large structures like bridges or tall buildings,” said Tran.

“But the addition of graphene oxide creates the possibility of an electrical circuit in concrete structures, which could help detect structural issues, changes in temperature and other environmental factors.”

While the research was preliminary, Tran added that the graphene oxide has potential to make 3D printed concrete more viable in the industry industry, which could have effects on cost and sustainability.

“Current concrete structures are created using formwork, which is where you create a mold before pouring fresh concrete mixture into it,” he said. “Formwork requires a lot of labor, time and money, and it often creates a lot of waste.

“With 3D printed concrete, not only does it help save time, money and labor, but you can also create more complex structures and reuse some construction waste in cement-based materials.”

The study says that 3D printed concrete, which uses layer-by-layer printing, can potentially lead to weaker bonds between each layer. Alternatively, adding graphene oxide into the concrete reportedly makes it easier to extrude, creates better inter-layer bonding and can help maximize strength.

According to a release from RMIT, engineers found the addition of graphene oxide, a nanomaterial commonly used in batteries and electronic gadgets, gave concrete electrical conductivity.

“Graphene oxide has functional groups on its surface, which are like sticky spots on the surface of a material that can grab onto other things,” Tran said.

“These 'sticky spots' are mainly made of various functional groups containing oxygen, which play a crucial role in facilitating its stronger bonds with other materials like cement. This strong bonding can improve the overall strength of the concrete.

“However, more research is needed to test if concrete with graphene oxide can match or surpass the strength of traditionally cast concrete.” 

Lead researcher and RMIT Ph.D. candidate Junli Liu also said the strength of the concrete could be increased if the bond between graphene oxide and the concrete mixture was improved.  

RMIT explains that the research tested two dosages of graphene oxide in cement and found the lower dosage (0.015% of the weight of cement) was stronger than the higher one (0.03% of the weight of cement). 

However, Tran noted that adding too much graphene oxide could impact the strength and workability of the concrete mix, which can cause potential issues with printability, strength and durability.  

“Concrete is a carefully balanced mixture. Adding too much graphene oxide can disrupt this balance, particularly the hydration process, which is crucial for concrete strength,” Tran said. “Too much graphene oxide can impact the flow of concrete, making it harder to extrude and therefore creating a structure with more gaps between layers of concrete.

“Graphene oxide can also clump together instead of spreading out evenly, which can create weak spots in the concrete and reduce its overall strength.”

The next phase of the research will reportedly study the electrical conductivity of graphene oxide in concrete, testing its viability as a potential smart material.

Junli Liu, Phuong Tran, Thusitha Ginigaddara and Priyan Mendis are also co-authors on the study.

   

Tagged categories: 3D printing; 3D Printing; Additives; Asia Pacific; Cement; Climate monitoring; Colleges and Universities; concrete; EMEA (Europe, Middle East and Africa); Good Technical Practice; Graphene; Health and safety; Latin America; North America; Program/Project Management; Projects - Commercial; Quality control; Research and development; Safety; Technology; Z-Continents

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