Nanocomposites as Substituent of Cement: Structure and Mechanical Properties

To date, the scientific research in the field of recycling of construction and demolition wastes was focused on the production of concrete, cements, and bricks. The attainment of these products was limited to the addition of suitable binder contents, such as lime or cement, compaction, and possibly heat treatment, without a concrete recycling method. In this paper, new cement materials consisting of 2.5 weight% composite and originating from construction and demolition waste powder, were prepared and investigated in view of applications in the construction industry as a substituent of cement. The materials with recycled powder from construction and demolition wastes were characterized by X-ray diffraction (XRD), infrared (IR) and nuclear magnetic resonance (NMR) spectroscopy. The XRD data indicate vitroceramic structures with varied crystalline phases. The NMR relaxometry data show four reservoirs of water associated with bounded water and with three types of pores in the composite construction material. The micro-Vickers hardness was measured to reflect the influence of composite nature in the local mechanical properties of the composite-cement for the mixture with Portland cement and (EC) expired cement.

Automated summary

Until now, the focus of scientific research on recycling construction and demolition waste has been on the production of concrete, cements, and bricks. Existing methods involve the addition of binders, compaction, and possibly heat treatment, but lack a specific concrete recycling method. This study aims to develop new cement materials using 2.5% composite derived from construction and demolition waste powder for substitution in the construction industry. Characterization of the materials was done using X-ray diffraction (XRD), infrared (IR), and nuclear magnetic resonance (NMR) spectroscopy, revealing varied crystalline phases and reservoirs of water in the composite construction material. Micro-Vickers hardness measurements were taken to assess the local mechanical properties of the composite-cement mixture.