No abstract

a uni-axial stress-strain curve, both in the tensile and in the compressive state. Nonlinear stressstrain curves may also be defined for bar and grid reinforcement.

Fiber reinforced polymer (FRP) bars are widely used in building structures, especially that are exposed to the aggressive environment influence and other special conditions. Nevertheless, due to the low FRP (e.g. glass, basalt, aramid fibers reinforced polymers) bars modulus of elasticity, exceeding crack opening width, as well as deflections can be observed. FRP bars pretensioning is considered as an effective method of its structural performance increasing. Physico-chemical method of the FRP bars pretensioning based on the self-stressing concrete utilizing is an alternative to the mechanical method and in its turn doesn’t need for special devices and anchorage systems as well as qualified personnel. Assessment of the initial stress-strain state obtained during self-stressing concrete expansion stage in the reinforced self-stressed members is presented. Diagram method of the self-stressing parameters verification based on the static loading tests results is presented. Comparison of the initial stress-strain state obtained during concrete expansion stage and predicted by the proposed model, as well as assessment of its influence on the behavior at the static loading stage in cases of the self-stressed reinforced with FRP bars members and traditionally reinforced with steel bars self-stressed members was performed.

Строительство и реконструкция 74 _________________________________________________________ №5 (85) 2019 (сентябрь-октябрь) 15. Mandy Korff. Deformations and damage to buildings adjacent to deep excavations in soft soils. 1001307-004-GEO-0002, Version 02, 26 November 2009, Deltares, 2009, 143 p. 16. Chunyuk D.YU., Sergeyev S.A. Otsenka ispol'zovaniya metoda konechnykh elementov pri usilenii fundamentov rekonstruiruyemykh zdaniy [Evaluation of the use of the finite element method for strengthening the foundations of reconstructed buildings]. V mire nauchnykh otkrytiy.