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The paper shows the promising use of sea sand for additive technologies in construction. The use of sea sand reduces the setting time of the concrete mix and increases the initial strength compared to conventional quarry construction sand. A comparative analysis of the characteristics of sea and quarry sands was performed. It has been experimentally proven that the use of sea sand instead of quarry sand in fine-grained concrete mix leads to a decrease in the setting time of the fresh mix and an increase in the strength of concrete samples. The flexural strength and compressive strength of samples containing sea sand at the age of 28 days increases by 35.7% and 16.7%, respectively, comparing to samples containing quarry sand.

The possibility of complex experimental study of the structure and properties of modern multicomponent concretes combining the influence of mechanical activation of the initial powder components of building mixtures, the rheology of concrete solutions, the structure of the concrete mixture, the distribution of various components and pores, the nature of damage and destruction at various stages of concrete strength testing is considered. The classical set of experimental methods for studying the rheological characteristics and strength of concretes at various setting stages is supplemented by studies of the concrete structure using X-ray computed tomography. The developing approach allows to solve the fundamental problems of building material science of concrete.

Three-dimensional printing is an innovative digital technology and is one of the most significant achievements in the industrial and technological development of modernity. Digital 3D technologies have reached a colossal level of development over a period of about half a century since their invention. Using 3D printing in the construction of low-rise buildings, it becomes possible to implement almost any ideas and achieve the best architectural expressiveness of objects. The aim of this work is to create cement-based compounds that can be used in additive construction methods. A review of the scientific literature on this topic was carried out, the main components of the mixture were identified, and a series of field experiments were conducted. According to the results of the work, the optimal composition for 3D construction printing was determined.

Nanomodified concrete is obtained from multicomponent dry building mixes based on Portland cement containing nanoscale filler particles. This paper examines the cement-sand mixture activated in a high-energy mill as a nanomodifier. The result is the gain in strength of concrete in the initial hardening time. The influence of fractional characteristics of sand on the activation process is analyzed. Three sand samples of different deposits of the Kaliningrad region characterized by different size and content of dust and clay particles were studied. The results of tests of samples of fine-grained concrete with activated and non-activated components for the initial compressive strength at the age of 0-90 minutes after the preparation of the mixture are presented. It is noted that the mechanical activation of cement-sand mixture is most effective when there are large fractions in the activated sand.