The Deformation of Partially Prestressed Elements Subjected to Repeated Static Loads

Abstract

The article deals with the change in the deflection of partially prestressed elements under repeated loading. Depending on the classes and the ratio of stressed and non-tensioned reinforcement, the effect of different levels of the repeated load application on the deformability index of the bent ferro-concrete elements is analyzed. Analysis of the experimental and calculated values ​​of deflections of rectangular profile beams after application of static repeated loads showed that regulatory documents underestimate the effect of the operational level repeated loads on the change in deflections at both average and high loading levels by more than 30%. Comparison of deflection values ​​was made immediately after application of repeated loads at the level of 60% from the destructive ones and after lifting the load to the level of 80%. To correct the values ​​of deflections within the limits of the calculated dependences of the norms, when subjected to the operational level repeated loads, it is proposed to take the value of the coefficient characterizing the elastoplastic properties of concrete equal to 0.3 for practical calculations. The results of the study increase the convergence of the experimental and theoretical values ​​of deflections in the range considered.

Adaptive control of housing and utilities infrastructure objects

“…Housing and utilities infrastructure objects include building of kindergarten [7], residential buildings [8,9], district heating [10,11] and other objects. The thermal behavior of buildings changes from quasi-stationary [12] to dynamic [13,14]. Switch to a decentralized distributed adaptive system of production facilities control might become a complementary tool of housing and utilities infrastructure objects control systems upgrade.…”