Influence of Graphene Oxide on the Mechanical Properties, Fracture Toughness, and Microhardness of Recycled Concrete

Abstract

There is a constant drive to improve the properties of recycled concrete owing to its inferior strength and fracture toughness compared to normal concrete and recent progress in graphene oxide (GO) nanomaterials impelling nanosized reinforcements to recycled concrete. Here, GO-modified natural sand (NS)- or recycled sand (RS)-based mortars (GONMs or GORMs) with six GO fractions (wGOs) were fabricated to explore their 28 d mechanical strengths (f28t, f28c), fracture toughness (KIC, δc), and microhardness (Hv), as well as their crystal phases (using X-ray powder diffraction) and microstructures (using scanning electronic microscopy). Results reveal, greater enhancements in mechanical strengths (4.50% and 10.61% in f28t, 4.76% and 13.87% in f28c), fracture toughness (16.49% and 38.17% in KIC, 160.14% and 286.59% in δc), and microhardness (21.02% and 52.70% in Hv) of GORM with just 0.025 wt‰ and 0.05 wt‰ GO, respectively, with respect to the control are achieved when comparing with those of GONM with the same wGO. More zigzag surfaces, more irregular weak interface slips, and the relatively lower strengths of RS bring the superiority of the template and reshaping effects of GO into full play in GORM rather than in GONM. These outcomes benefit a wide range of applications of recycled concrete products.

Effect of Graphene Oxide on Mechanical Properties and Durability of Ultra-High-Performance Concrete Prepared from Recycled Sand

“…With the advancement of nanotechnology, the mixing of nanomaterials into cement-based materials has been increasingly researched. A wide variety of nanomaterials have been investigated, including nano-silicon oxide [ 23 , 24 , 25 ], nano-titanium oxide [ 26 ], carbon nanotubes [ 27 , 28 , 29 ], sulfonated graphene [ 30 , 31 , 32 ], and graphene oxide (GO) [ 33 , 34 , 35 , 36 , 37 ]. GO is a new type of nanomaterial with excellent mechanical properties and good dispersion properties.…”

Optimization of calcium carbonate whisker reinforced cement paste for rheology and fracture properties using response surface methodology

“…a higher w/c is more beneficial for MWCNTs dispersion. The highest relative fracture toughness is presented by the Luo et al 43 study, which can be contributed to the addition of high MWCNTs content in cement paste with high w/c. In addition to this, the equivalent relative fracture toughness is obtained in this study by using the multiobjective simultaneous optimization technique, as compared to that of Cao et al 9 results, but with a significant reduced dosage of CW and cement.…”

Effect of Short Fiber Reinforcements on Fracture Performance of Cement-Based Materials: A Systematic Review Approach

“…Well-dispersed CWs in a matrix could efficiently delay micro-crack development and propagation, as well as improve mechanical properties [ 207 ]. Additionally, GO addition in concrete can improve fracture toughness because GO is highly reactive and hydrophilic, and it might induce active group hydration in cement [ 195 ]. Fibers (such as MWCNTs, CW, and GO) show valuable microscopic crack bridging, interfacial improvement, and filler action in matrixes.…”

“…Fibers (such as MWCNTs, CW, and GO) show valuable microscopic crack bridging, interfacial improvement, and filler action in matrixes. GO fibers and MWCNTs exhibit other nucleation effects because these micro-fibers have the ability to facilitate the hydration of cement [ 11 , 194 , 195 ]. The multi-scale fracture and mechanical characteristics of CBMs can be improved by uniformly distributed MWCNTs and carbon nanofibers (CNFs) [ 10 , 78 ].…”

“…Liu et al [ 194 ] subjected MWCNTs to ultrasonic treatment, and the results revealed a significant increase in fracture properties of cement paste. Furthermore, Luo et al [ 195 ] used a high-range water reducer based on a polycarboxylate polymer as a dispersant for GO.…”