Improvement of Regulatory Calculation of the Load-Carrying Capacity of Vibrated, Centrifuged, and Vibrocentrifuged-Based Iron-Concrete Columns with Variatropic Structure

Author(s):  
Л. Р. Маилян ◽  
С. А. Стельмах ◽  
Е. М. Щербань ◽  
А. А. Чернильник

Состояние проблемы. Сжатые железобетонные элементы изготавливаются по трем основным технологиям - вибрированием, центрифугированием и виброцентрифугированием. Однако все основные расчетные зависимости для определения их несущей способности выведены, исходя из основного постулата - постоянства и равенства характеристик бетона по сечению, что соответствует действительности лишь в вибрированных колоннах. Результаты. Разработан усовершенствованный нормативный подход к расчету прочности центрифугированных и виброцентрифугированных железобетонных колонн, заключающийся в использовании в расчете интегральных или дифференциальных характеристик бетона. Выводы. Расчет прочности коротких центрально сжатых вибрированных, центрифугированных и виброцентрифугированных колонн по усовершенствованному нормативному подходу дал наилучшие результаты с использованием дифференциальных характеристик бетона, различающихся по сечению. Statement of the problem. Compressed reinforced concrete elements are manufactured according to three main technologies - vibrating, centrifuging and vibrocentrifugation. However, all the main calculated dependences for determining their load-bearing capacity were derived based on the main postulate - the constancy and equality of the characteristics of concrete over the cross section, which corresponds to reality only in vibrated columns. Results. An improved regulatory approach has been developed for calculating the strength of centrifuged and vibrocentrifuged reinforced concrete columns, which involves using the calculation of integral or differential characteristics of concrete. Conclusions. Strength analysis of short centrally compressed vibrated, centrifuged and vibrocentrifuged columns using an improved regulatory approach yielded the best results using differential characteristics of concrete varying in cross section.

Structures ◽  
2020 ◽  
Vol 28 ◽  
pp. 1557-1571
Author(s):  
Ali Raza ◽  
Syyed Adnan Raheel Shah ◽  
Faraz ul Haq ◽  
Hunain Arshad ◽  
Syed Safdar Raza ◽  
...  

2020 ◽  
Vol 24 (5) ◽  
pp. 77-91
Author(s):  
Mohammad Javad Memar ◽  
Ali Kheyroddin ◽  
Ali Hemmati

Engineered cementitious composite (ECC) can be used for strengthening of concrete columns due to its similar structure and suitable connection to normal concrete and its special tension behavior. In this study, to analyse the columns, finite element (FE) method was used after verification by experimental results. Reference column was strengthened by normal concrete and ECC jacketing. The effects of type of jacket material, longitudinal reinforcement, compressive stress and ultimate tensile strain of ECC on variations of eccentric load-bending moment (P-M) interaction curves were investigated. Results showed that the use of ECC instead of normal concrete can increase load carrying capacity of strengthened column, due to tensile strain hardening behavior of this material. It was found that, amount of this increase depends on eccentricity of eccentric load and varying from 0.4-23%. In ECC jacketing, tensile cracks are continuous, but in concrete jacketing, there were discrete cracks and more quantity of damages. Due to higher load carrying capacity and better distribution of tensile cracks in ECC jacketing than normal concrete jacketing, the use of ECC is suitable for strengthening of reinforced concrete columns. Load carrying capacity of columns under concentric load and pure bending moment were calculated by theoretical method and the results were compared with FE.


2013 ◽  
Vol 57 ◽  
pp. 232-237 ◽  
Author(s):  
Mykolas Daugevičius ◽  
Juozas Valivonis ◽  
Artūras Beinaravičius ◽  
Tomas Skuturna ◽  
Marius Budvytis

2002 ◽  
Vol 10 (4) ◽  
pp. 273-280
Author(s):  
K. Friedrich ◽  
N. Glienke ◽  
J. Flöck ◽  
F. Haupert ◽  
S. A. Paipetis

An experimental study was conducted to compare various composite systems with different fibres (E-glass and carbon) in two different thermoplastic matrices (PPS, PEEK) for their strengthening efficiency for wrapped concrete columns. The results indicated that the use of E-glass fibres within a polyphenylenesulfide matrix to externally reinforce concrete columns is quite effective. The carbon fibre PEEK based system does not show much improvement in the load carrying capacity. The thickness of wrap/radius of concrete column-ratio also has an influence on the strengthening efficiency. For example ten layers of glass fibre/PPS-tapes resulted in a five fold improvement of the compressive strength of the non-reinforced concrete. Predamaged samples with the same amount of reinforcement were still 4.5 times stronger than the undamaged, non-reinforced concrete.


Sign in / Sign up

Export Citation Format

Share Document