Experimental Study on Mechanical and Functional Properties of Reduced Graphene Oxide/Cement Composites

Abstract

<jats:p>This study develops a novel self-sensing cement composite by simply mixing reduced graphene oxide (rGO) in cementitious material. The experimental results indicate that, owing to the excellent dispersion method, the nucleation and two-dimensional morphological effect of rGO optimizes the microstructure inside cement-based material. This would increase the electric conductivity, thermal property and self-induction system of cement material, making it much easier for cementitious material to better warn about impending damage. The use of rGO can improve the electric conductivity and electric shielding property of rGO-paste by 23% and 45%. The remarkable enhancement was that the voltage change rate of 1.00 wt.%-rGO paste under six-cycle loads increased from 4% to 12.6%, with strain sensitivity up to 363.10, without compromising the mechanical properties. The maximum compressive strength of the rGO-mortar can be increased from 55 MPa to 71 MPa. In conclusion, the research findings provide an effective strategy to functionalize cement materials by mixing rGO and to achieve the stronger electric shielding property and higher-pressure sensitivity of rGO–cement composites, leading to the development of a novel high strength self-sensing cement material with a flexural strength up to 49%.</jats:p>

Piezoresistive Properties of Natural Hydraulic Lime Binary Pastes with Incorporated Carbon-Based Nanomaterials under Cyclic Compressive Loadings

“…It is noted that at the lower loading (10%), the electrical resistance change keeps a constant change of 10%, but the absolute value of the electrical resistance decreases. Zhang et al [ 34 ] reported similar behavior of rGO-cement mortars with 0.5 wt.% rGO. They found out that the piezoresistive response stabilizes at higher concentrations of rGO [ 34 ].…”

“…Najafishad et al [ 33 ] found that the incorporation of 0.15 wt.% GO in cement leads to 70% decrease in electrical resistance, while the same concentration of CNTs leads to 78% respective decrease. Zhang et al [ 34 ] examined the effect of rGO (up to 4 wt.%) in cementitious matrix. They found that electrical resistivity decreases with increasing concentration of rGO, reaching a plateau at 2%, where the electrical resistivity was reduced by 40%.…”

Electrical, Piezoresistive and Electromagnetic Properties of Graphene Reinforced Cement Composites: A Review

“…Phrompet et al [31] demonstrated that the incorporation of rGO effectively improved the mechanical, thermal, and dielectric properties of CCMs. Zhang et al [53] simply mixed rGO into cement and the electromagnetic shielding effectiveness was significantly improved. As shown in Figure 4, the experimental sample with 1.0 wt% rGO added has a value of 16-21 dB (GC1) for electromagnetic shielding effectiveness, an enhancement of 30% to 45% compared to the sample without rGO (GC0).…”

“…Zhang et al [53] developed a novel self-sensing cement composite by adding rGO. The experiments indicated that the dispersion of the rGO increased the electrical conductivity by 23%.…”

A Recurrent Neural Network-Based Method for Dynamic Load Identification of Beam Structures

“…The error introduced in any segment will greatly affect the ultimate identification result, which is similar to other fuzzy fields [50][51][52]. Moreover, different material properties will affect the solution for the problem relating to structural dynamic characteristics [53][54][55][56], which makes identification difficult. Scholars usually use the metaphor of the "black box" to describe the problem of dynamic load identification and neural networks.…”