NRCCC 2019 : Special Issue on Nano Reinforced Cement and Concrete Composites

At present, the use of nanomaterials (NM) to improve the performance of cement and concrete matrixes appears as a potential alternative to the exclusive use of Portland cement (PC). Similarly, there is currently no doubt in the construction industry (CI) about the pressing need to reduce consumption of PC. The CI represents the world's third-largest industrial energy consumer, and the component related to the production of PC alone represents 7% of the carbon dioxide (CO2) emissions globally. PC is undoubtedly the most used material in construction in terms of its relative volume. Raw materials for PC production are generally plentiful, and available throughout the world. In this sense, it is imperative that the cement industry obtains viable technical solutions that allow the reduction of PC consumption. That reduction can be achieved either by its direct replacement with another material (as for example with the use of fly ash), or by improving cement and concrete matrix performance with the addition of new materials, such as NM. This second option is quite interesting since it allows, for example, maintaining the cement and concrete matrix properties/characteristics, reducing PC consumption by adding a tiny amount of NM.

The NM evolution has allowed the production of new cement-based nanocomposites with previously unimaginable properties. In general, NM can be grouped into three main types: Zero-dimensional (0D) nanoparticles, such as nanosilica; one-dimensional (1D) nanofibers, such as carbon nanotubes; and lastly, the most recent two-dimensional (2D) nanosheet, i.e., graphene oxide (GO). These materials, especially 1D and 2D NM, have the ability to, in very small dosages, strengthen the cement and concrete matrix through reinforcement and pore refinement. This allows for conventional cement composites to achieve higher performance levels or to maintain the same performance levels with decreasing PC consumption.

The aim of this Special Issue is to explore the potential of use of nanomaterials in the production of mortar and concrete composites and to discuss new opportunities in this field.