UCLA study shows graphene oxide strengthens concrete for commercial use
Researchers at UCLA have demonstrated that adding 0.05 percent graphene oxide by weight to concrete can increase its 28-day compressive strength by over 20 percent. This finding clarifies graphene oxide's role in enhancing concrete strength, potentially paving the way for its effective commercial application in construction.
The University of California at Los Angeles (UCLA) has conducted a study revealing how graphene oxide (GO) can enhance the strength of concrete, potentially facilitating its commercial application. This research, led by a multidisciplinary team, was recently published.
Graphene oxide has been explored as an additive to improve concrete strength, but past studies have shown inconsistent results, and the mechanisms of its effectiveness were not fully understood. The UCLA team has now clarified these mechanisms and proposed a method for more effective use of GO in commercial concrete applications.
Concrete's strength is influenced by its cement clinker content and water-to-cement ratio. The study demonstrated that incorporating GO at a dosage of 0.05 percent by weight of binder material can increase the 28-day compressive strength of concrete by over 20 percent. The research analyzed factors affecting GO's reinforcing capabilities, including dosage, physical treatments such as sonication, and chemical treatments like the superplasticizer polycarboxylate ether (PCE). PCE, beyond its role as a superplasticizer, acts as a surfactant modifying the dispersion of nanomaterials like GO.
Gaurav Sant, a Pritzker professor of sustainability at UCLA and a project leader, stated that the findings provide practical guidance for using GO effectively in concrete at low dosages. The study found that GO's strength-enhancing effects are due to a balance between hydration-seeding and pore-refinement. GO's high specific surface area offers numerous nucleation sites that speed up cement hydration, enhancing early-age strength, while its nanoscale dimensions allow for pore filling and microstructural densification, improving later-age strength.
Sonication and PCE additions control GO dispersion in the concrete mix, affecting its effective surface area. Sant explained that sonication exfoliates multilayer GO sheets into single-layer sheets, increasing available surface area, while PCE adsorption reduces it. This allows for co-optimization of hydration-seeding and microstructural densification, maximizing GO's effectiveness at any given dosage.
Source: Graphene Feed