On the influence of cross-section and reinforcement of reinforced concrete constructions on the concentration of coarse aggregate in concrete with frame structure

Abstract

Concretes with frame structure produced by using the technology of separate concreting by immersing a coarse aggregate in a low-viscosity mortar matrix due to an increased concentration of coarse aggregate have an increased E-modulus, reduced creep coefficient and cement volume in concrete compared to traditional vibrational compaction concretes. Production concrete using separate concreting technology by immersing a coarse aggregate in a mortar matrix with low-viscosity allows to obtain a frame structure of concrete with a concentration of coarse aggregate up to 0.7 when a voidness of coarse aggregate is equal 0.28. The real concentration of coarse aggregate in a concrete structure depends on the particle size of the coarse aggregate, the cross-section dimensions of the structure, and the reinforcement coefficient. The influence of geometric dimensions and the coefficient of reinforcement on the concentration of coarse aggregate in the concrete with frame structure is studied. The concentration of coarse aggregate decreases with the growth of the S/V modulus (S – area, m2, V – volume, m3) and the reinforcement coefficient, but the decrease in the E-modulus does not exceed 5%. Conclusion: regardless of the type of construction and reinforcement, the concrete of the frame structure must have a sufficiently high uniformity of deformation properties