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

The search for technological solutions for the organization of lean production at precast concrete enterprises was carried out. Options for rational use of rock crushing screenings as a filler and filler for self-compacting fine-grained concrete are considered. The optimal dosage of limestone crushing screenings in the composition of fine aggregate for the preparation of self-compacting mixtures has been determined. It was found that the enrichment of very fine Sands with large fractions of Sandstone crushing screening in an optimal amount reduces the intergranular voidness and reduces the water demand of the fine-grained mixture.

Keywords: lean production, rock crushing screenings, optimization of grain composition of aggregate, self-compacting fine-grained concretes, superplasticizer based on polyaryl and polycarboxylate esters