Nodes of Experimental Installations for Testing Concrete for Creep

Installations of the mid-twentieth century for testing concrete for creep, as a rule, have significant wear and are not intended for testing new concrete. To carry out testing of modern high-strength concrete, their modernization and retrofitting is required. Due to the lack of standard technical solutions, design and survey work is required in preparation for testing. The purpose of the presented study was to study the nodes and elements of spring installations for determining the creep of concrete and to establish the possibility of their use under increased loads, to modernize installations for the possibility of testing samples of various lengths without complete disassembly, to ensure safety during such tests. To determine the strength and stiffness parameters of the springs, it was necessary to conduct two-stage tests with the development of special equipment. Also, according to the results of the evaluation of the hinge assemblies for axial load transfer to the sample, their replacement with a change in design solutions was required. According to the results of experimental studies, individual springs and thrust hinge elements were fragilely destroyed, in connection with which a hinge assembly of a new design was developed, changes have been made to the design of the installation to ensure the physical protection of maintenance personnel, a modular system of steel spacers with protection against horizontal movement has been developed, which makes it possible to test samples of different lengths on existing installations without changing the configuration of the installations themselves. An important result of the work is the proposed system of double experimental control, when first a random test of individual elements is carried out to assess the possible level of loads on the equipment, then a continuous control of the already assembled test installations is carried out for large loads relative to the planned experiment. Only in this case it is possible to simultaneously ensure high reliability of the results obtained during testing, reliability and durability of the equipment. Moreover, it is impossible to carry out such work only numerically without testing, as practice has shown.

P.D. ARLENINOV^1,2, Candidate of Sciences (Engineering) (This email address is being protected from spambots. You need JavaScript enabled to view it.);
S.B. KRYLOV¹, Doctor of Sciences (Engineering);
D.V. KONIN³, Candidate of Sciences (Engineering);
V.A. NESCHADIMOV², Candidate of Sciences (Engineering)

¹ Research Institute of Concrete and Reinforced Concrete named after A.A. Gvozdev (NIIZHB), JSC “Research Center of Construction” (6, 2nd Institutskaya Street, Moscow, 109428, Russian Federation)
² National Research Moscow State University of Civil Engineering (26, Yaroslavskoye Highway, Moscow, 129337, Russian Federation)
³ Central Research Institute of Building Structures named after. V.A. Kucherenko (TSNIISK), JSC “Research Center of Construction” (6, bldg. 5, 2nd Institutskaya Street, Moscow, 109428, Russian Federation)

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