From nano-scale to macrostructure in composite for additive technologies

Abstract

Onrush of additive technologies might allow a 3D concrete printing method to become more profitable and efficient for building unique constructions than traditional methods of building. Until the XXI century, the science paid special attention to phenomena and processes at two levels: microscopic scale (400- 760 nm) and atomic and subatomic scale (less than 1 nm).However, the range from 1 nm to 100 nm which is consideredwithin the science of “nano” was not under consideration. But the properties of most materials are defined by their structure at th nanolevel. Considering a mix for 3D printing as a composite material produced from fine aggregate, pastematrix, water andair-bubble voids, it is possible to state that the main problem lies in regulating the process of forming the material structure in a bottom-up way (from nanoscale to macrostructure of the composite material) by nanomodifying the interphase boundary as well as in controlling the kinetics of all chemical reactions accompanying setting processes and optimizing processing activities and service properties of mortars and composites by means of nanomodifiers. It is proved that influencing purposefully the processing properties of high-concentrated mineral suspensions applied in construction industry allows directed synthesis of macromolecules of the nano-size and definite structure which have high absorptive capacity on particle surface and are able to modify the structure of the boundary layer. Modifying cement particles at the nanoscale allows decreasing water requirements of the mix and obtaining the required plastic strength and accelerated strength generation of cement for additive technologies.