Investigation of the Influence of the Initial Composition of Heavy Concrete Designed for the Manufacture of Ring-Section Products on its Properties

Abstract

The authors conducted the analysis of scientific and technical references relating to the issue of increasing maintenance reliability of pre-stressed reinforced concrete by means of taking into account concrete non-homogeneity in the calculations of strength, deformability and crack resistance of the reinforced concrete products with annular section. The authors stated the opportunity to increase the quality of concrete intended for centrifugation by means of regulating the properties of used materials. It was identified that applying disperse-reinforced fibers resulted in increase in bending tensile strength, decrease in shrinkage, increase in crack resistance and material resistance towards alternate freezing and thawing, drying and humidification cycles. Upon the results of conducted research and comparison of the properties of various fibers, the authors obtained regularities and application rules on fiber use and gave recommendations in terms of applying one of another fiber type. On the basis of the analysis of obtained results the authors made the conclusion that the highest effect in all tests was observed at the application of basalt fibers as they provide for a higher dispersion of cement rock reinforcement while the basalt fiber itself has a higher strength comparing with any other polymer fiber. Further, the authors conducted the research of mechanical properties characteristic for test beams made of heavy concrete to manufacture the annular section products by means of centrifugation. The obtained dependences allow making a conclusion that the percentage ratio of applied crushed stone fractions Fr 5-10 / Fr 5-20 = 50 / 50 under otherwise equal conditions has the highest influence on the heavy concrete ground strength.