Visnyk LNAU: Architecture and Farm Building 2018 №19: 41-45
COMPUTATIONAL MODELS OF FLAT REINFORCED CONCRETE SLABS STRENGTHENED BY EXTERNAL STRESSED REINFORCE-MENT
O. Zhuravskyi, Candidate of Technical Sciences
V. Tymoshchuk, Post-graduate Student
Kyiv National University of Civil Engineering and Architecture
During the arrangement of monolithic reinforced concrete flat roofs, problems with over-deflection and cracks occur. They can occur both during operation and during construction. The reasons that cause excessive deflections can be attributed to: deviation from manufacturing technology, design errors, etc. For large spans of monolithic plates (more than 6 m) it is recommended to use pre-stressed fittings. To reinforce reinforced concrete slabs you can use external tensile reinforcement, which will serve as external reinforcement.
The purpose of the dissertation research is to carry out theoretical calcula-tions and the experimental confirmation of the possibility of strengthening the flat reinforced concrete slabs with external stressed reinforcement, and influence of such strengthening on the subsequent operation of the slab under the increased load.
The calculation strengthening of direct reinforcement was made, that is, the reinforcement were parallel to the axes, for the experimental model of the slab at a scale of 1: 6. To calculate used software suite Lira 9.6.
Four calculation models were created: 1– linear calculation of the model without strengthening; 2 – linear calculation of the model with strengthening by direct reinforcement; 3 – nonlinear calculation of the model without strengthening; 4 – nonlinear calculation of the model after strengthening. To analyze the structures before amplifying and calculating the gain, it is better to use a nonlinear calculation method, since it shows the actual work of the structural reinforced concrete elements and allows you to see the complete picture of deformations, stresses and fractures in the element. In the future, it is planned to carry out an experimental study and compare the result with the theoretical calculation.
The results of theoretical researches of the calculation of flat reinforced concrete slabs strengthening by external stressed reinforcement in linear and non-linear formulation of problems are presented, and the results of two calculation variants are compared.
strengthening, flat reinforce concrete slab, external reinforcement, deformation, strength
- Lira 9.4. User's Guide. Fundamentals: study. way / Ye. B. Strelets-Streletsky et al. Kiev: FACT, 2008. 164 p.
- Glukhovskiy A. D. Reinforced concrete flat floors for multi-storey buildings. Moscow, 1956. 62 p.
- Mikhailov V. V. Pre-stressed reinforced concrete structures. Moscow: Stroizdat, 1978. 383 p.
- Leonhardt F. Stress-reinforced concrete and its practical application / per. Zhytomyrsky V. K. Moscow: Stroyizdat, 1957. 588 p.
- Zhuravsky O. D., Tymoshchuk V. A. Calculation of flat reinforced concrete slabs, strengthened with external stressed reinforcement. Building constructions. Theory and practice. Kyiv: KNUBA, 2017. Is. 1. Р. 193-198.