The paper analyzes existing 3D printing technologies in the context of application in construction. The experience of 3D printing application in commercial projects is considered. Scientific research on the improvement of various technologies is summarized. 3D printing technologies promising for construction - wire-arc and ultrasonic additive manufacturing - are identified.

Keywords: 3D printing, construction, additive technologies

The article presents a review of research on the subject of the special limiting state, which are of interest for the development of theory and practical applications. The results of the main works, which have not lost their relevance, are briefly presented. Perspective directions of development for improvement of the theory of the special limiting state are distinguished: 1) Taking into account in calculations the stiffness of nodal couplings, individual elements of structures. 2) Consideration of joint operation of prefabricated and prefabricated-monolithic structures, including shear stiffness of compound sections. 3) Consideration of temporal and spatial nature of impact. 4) Work on extension of application of the theory beyond calculations for progressive collapse.

Keywords: special limitstate, special effects, reinforced concrete, deformability, special limit state criteria