Growing Nanocrystalline Graphene on Aggregates for Conductive and Strong Smart Cement Composites

Abstract

Highly conductive concrete/mortar has been long pursued to realize structural health monitoring in the development of smartcement-based facilities. However, it remains challenging to significantly increase the electrical conductivity of concrete/mortar without lowering the compressive strength and flowability. Here, nanocrystalline-graphenecoated aggregates (termed Gr@AGs) are synthesized to break this conductivity−strength tradeoff. Admixing Gr@AGs with cement enables the construction of a conductive network of graphene that simultaneously strengthens the interfacial transition zone between aggregates and paste. As a result, high conductivity and improved mechanical properties have been simultaneously realized in Gr@AGs-based smart mortars. The significant positive effects of Gr@AGs are further enhanced by combining them with a low percentage of carbon fiber. Typically, the 28-day compressive/flexural strength of the optimized mortar increases by 12.2%/19.4%, with the electrical resistivity reduced by over 3 orders of magnitude from ∼4.6 × 10 5 to 182 Ω cm. On this basis, we demonstrate high-sensitivity cement-based piezoresistive sensors with a fractional change in resistivity as high as ∼25%, which is more than 1 order of magnitude higher than those reported in comparable systems. This study provides a solution to the critical issues in developing smart cementitious composites by taking full advantage of graphene's properties.

Dynamics of reduced graphene oxide: synthesis and structural models

“…59,63 Additionally, RGO has an inherited high electron mobility than spherical nanomaterials by virtue of a 2-D morphology that is attributed to condensed junctions and grain boundaries. 64,65 Excessive defect intensity may disrupt functionality in some applications, such as piezoelectric applications, as it interferes with electron transport. Nitrogen doping into the carbon framework of RGO has been reported to improve interfacial electron transfer in RGO, and therefore the conductivity increases as nitrogen atoms contribute to the additional electron.…”

Deterioration Effects of Oxidative Aging on Graphene-Asphalt Nanocomposite Interfaces: Multiscale Modeling

“…Graphene is a two-dimensional sheet of sp 2 -hybridized carbon with excellent mechanical, thermodynamic, and electrical properties, making it an ideal reinforcement for composite materials. − Hence, graphene-asphalt nanocomposites have been suggested as the main paving material for the next generation. The addition of a small amount of graphene can significantly improve the stability, rutting, and cracking resistance of asphalt. , This is because graphene adds a lot of nanoscale interfaces to asphalt.…”

Investigation of the performance of cement mortar incorporating lithium slag as a super-fine aggregate

“…However, less than 10% of lithium slag is utilized as a supplementary cementitious material for building material. Therefore, a large amount of lithium slag is landfilled, causing ecological environmental problems and wasting natural resources (Lu et al, 2023;. Few studies have examined the technology of the use and recovery of lithium slag.…”