Technical and Economic Efficiency of Using the Self-Compacting Concrete Mixtures in Monolithic Construction

Abstract

Introduction. The technical effect attained during construction of the monolithic reinforced concrete structures made of self-compacting concrete mixtures, which results in the increase of the actual strength of concrete, can be put to use to reduce the cross section of the structures and to cut down the consumption of the reinforcement. The paper aims to assess the technical and economic efficiency of the monolithic reinforced concrete structures made of high-strength self-compacting concrete, with the use of the construction waste, in meeting the goals of green construction.Materials and Methods. To assess the efficiency of the monolithic structure concreting options, the vibratory-compacting concrete mixture БСТ В25 П4 and the self-compacting mixture БСТ В40 РК1 were prepared using the Portland cement CEM0 42.5N. The crushed stone of fraction 5–10 mm was used as a coarse aggregate and natural sand and crushed sand from construction waste (concrete scrap) were used as a fine aggregate. To ensure the high fluidity of the mixtures, the additive Polyplast PK— a universal ester-based polycarboxylate superplasticizer was used. The calculation of the parameters of the reinforced concrete structures depending on the compressive strength of concrete was performed in the LIRA software package. The estimated cost of the works on construction of the reinforced concrete structures was determined for two alternative options that differed in the type of concrete mixture used, the method of its delivery to the place of concreting and in the method of compaction.Results. The calculation of the parameters of the reinforced concrete structures has been carried out, which showed that for the structures made of high-strength B40 class concrete, the cross-section thickness can be uniform along the entire height — 200 mm, whereas the amount of concrete can be 20% less than for B25 class concrete. The calculation of reinforcing parameters along the structures’ height in correlation to the strength of concrete showed that when using the self-compacting B40 class concrete, it is possible to reduce the design diameter and to cut down the consumption of the reinforcement. The expected economic effect of using the self-compacting high-strength concrete, calculated for concreting the structures of the volume of 433 m3 , can be 1639.5 rubbles.Discussion and Conclusion. The technical and economic efficiency of using the high-strength self-compacting concrete for concreting the monolithic reinforced concrete structures has been substantiated. As a result of using the self-compacting mixture and concrete pumping technology, the estimated cost of constructing the structures is reduced, the manpower inputs and labour costs are decreased, and, due to the use of the construction waste and refusal from utilising the electrical equipment for the vibratory compaction, the ecological effect is achieved.