Structural Design and Experimental Verification of Precast Columns from High Performance Concrete

2015 ◽  
Vol 1106 ◽  
pp. 110-113 ◽  
Author(s):  
Ctislav Fiala ◽  
Jaroslav Hejl ◽  
Vladimira Tomalova ◽  
Vlastimil Bilek ◽  
Tereza Pavlu ◽  
...  

Paper presents some results of long-term research of a new optimized subtle precast construction system based on high performance silicate composites. The system is particularly aimed for building construction in passive or zero-energy standard. Subtle structural elements from high performance concrete (HPC) can be integrated into building envelope of energy efficient buildings with significant reduction of envelope structure and avoiding risk of thermal bridges. Significant advantages of subtle elements are material and energy savings during production, transport, manipulation and construction on building site.Paper presents experimental verification of connection between columns and beams ensured by Peikko ́s PCs corbels. Moreover, production of two prototypes of high performance fibre reinforced columns over two floors is presented. Prototypes were casted in ŽPSV a.s. plant, Litice nad Orlicí in June 2014. Complex LCA analysis of three various reinforced concrete columns was performed. Analysis covers construction life phase. Consequently, environmental impacts of assessed variants were compared and evaluated. Results show that it is possible to reduce some impacts on the environment from 16 up to 65% in comparison with common solution of reinforced concrete columns due to the utilization of excellent mechanical properties of high performance concrete that enables the design of subtle structural elements.

2016 ◽  
Vol 249 ◽  
pp. 301-306
Author(s):  
Ctislav Fiala ◽  
Jaroslav Hejl ◽  
Vlastimil Bílek ◽  
Jan Růžička ◽  
Tomáš Vlach ◽  
...  

Mechanical properties of high performance concrete (HPC) enable design of subtle structural elements. Subtle HPC frame concept comes from the effort to integrate load bearing elements into building envelope in order to reduce risks of thermal bridges. Substantial advantages of subtle structural elements are material and energy savings during production, transportation, manipulation and assembling. Paper presents preparation and implementation of construction of experimental frame at University Centre UCEEB in Buštěhrad. Individual structural elements were made in prefa plant ŽPSV a.s. in Litice nad Orlicí. Construction of frame prototype is the result of long term research when the vertical and horizontal structural elements and their connections were successively designed and experimentally verified. This article shows experimental results of horizontal load bearing structures - floor panels and beams - in detail. Samples were tested by four-point bending test and also creep of floor panels was measured. Accomplished calculations, experimental verification and analysis have showed that subtle HPC frame is the effective solution from reliability aspects as well as from environmental and economical parameters. Minimal columns cross sections enable their complete implementation into building envelope and they also contribute to high quality architectonic solution of buildings interiors.


2016 ◽  
Vol 249 ◽  
pp. 203-208
Author(s):  
Peter Kendický ◽  
Vladimír Benko ◽  
Tomáš Gúcky

The use of non-linear methods for design of slender concrete columns by European standards. For the verification of non-linear design methods it is important to compare their results with results of experiments. Within the applied research of the Faculty of Civil Engineering at Slovak University of Technology in Bratislava in cooperation with the company ZIPP Bratislava LTD the experimental verification of the slender reinforced concrete columns was realized. In the paper the authors present the preparation and process one of three series of slender reinforced concrete columns, which were made to verify the reliability of various design methods. Columns of planned second series were designed from high performance concrete C100/115, but the material tests showed that the strength class of concrete was C70/85. The columns, subjected to axial force and bending moment were designed to fail due to loss of stability before the resistance of the critical cross-section is reached. The expected compressive strain in concrete was 1,5 ‰.


2017 ◽  
Vol 259 ◽  
pp. 275-279 ◽  
Author(s):  
Ctislav Fiala ◽  
Jaroslav Hejl ◽  
Vlastimil Bílek ◽  
Tomáš Vlach ◽  
Michal Ženíšek ◽  
...  

Mechanical properties of high performance concrete (HPC) enable design of subtle structural elements. Subtle HPC frame concept comes from the effort to integrate load bearing elements into building envelope in order to reduce risks of thermal bridges. Substantial advantages of subtle structural elements are material and energy savings during production, transportation, manipulation and assembling. Paper presents implementation of construction of experimental frame at University Centre UCEEB in Buštěhrad. Individual structural elements were made in prefa plant ŽPSV a.s. in Litice nad Orlicí and Čerčany, the company also assembled the experimental frame. The frame was built from February to April 2016. Within June and July, the construction was tested by static loading test, which partial results are presented in the paper. Accomplished calculations, experimental verification and analysis show that subtle HPC frame is the effective solution from reliability aspects as well as from environmental and economical parameters.


2020 ◽  
Vol 14 (1) ◽  
pp. 141-151
Author(s):  
Hadi N. G. Al-Maliki

Introduction: This study includes the analysis of the strength capacity of high performance reinforced concrete columns subjected to concentric axial loading. The main variables are based on the compressive strength of concrete and steel reinforcing ratios. All the columns are fixed, supported by two ends. Methods: This study is based on a calculation done according to ACI Code-318M-2011 equations for columns analysis to evaluate the ultimate strength then applied these load on samples to compare between them by software program Prokon V.3. The comparison is based on reinforcement ratio and moment resistance capacity. Results: The analysis results show that when increasing the main reinforcement with high-performance concrete led, there will be an increased load capacity by about (40 to 215%) and moment resistance capacity by about (35 to 50%) with the same load conditions. According to the analysis of the results, the moment resistance capacity of constant sample value with different reinforcing ratio leads to these resist depending on the load applied, and the concrete compressive strength of columns. Conclusion: Reasonable correlation of the results is demonstrated, which ensured the adequacy of the analysis by test program, both hand calculation and software Prokon.V.3.


2021 ◽  
Vol 322 ◽  
pp. 142-150
Author(s):  
Jakub Dobrý ◽  
Vladimír Benko ◽  
Miroslav Kováčik ◽  
Hannes Wolfger

The columns have been part of the constructions since the beginning of the buildings and have retained their design and construction importance to the present. The advantage of using more slender elements are less material consumption and more usable space in the interiors. The continuous improvement of the building materials and the use of hybrid structural elements leads to the downsizing of the structural elements. The aim of this article is the nonlinear analysis of the slender rein-forced concrete columns and the loss of stability verified by the experimental tests. Nonlinear calculations can be considered as the most accurate calculation option for the load bearing structural elements. On the other hand, the effect of the “black box” has been, and will be the cause of a large number of building defects. In the Eurocode 2 in chapter 5.8.6 of the European Concrete Design Standard, there is a possibility of using the general nonlinear method in practice, even for the com-pressed elements. In the design of the slender structures, the influence of second-order theory is a very important part of the design. In this publication are described theoretical and experimental analyses of the slender columns, that failed due to loss of stability inside of their design interaction diagram - much sooner than the critical cross-sections reached its resistance. As a part of the experimental preparations, reinforced concrete columns were designed, based on numerous numerical analyses. Later, the chosen columns were tested in the laboratories of TU Wien in Vienna. Experimental verification is one of the main parts of my dissertation thesis.


2021 ◽  
Vol 28 (2) ◽  
pp. 54-72
Author(s):  
Abd-al-Salam Al-Hazragi ◽  
Assim Lateef

This article investigates the behaviour of strengthened concrete columns using jacketing ultra-high-performance fiber reinforced concrete (UHPFRC) and carbon fiber-reinforced polymer (CFRP) under uniaxial loaded. The jacket was connected to the column core using shear connectors and (CFRP) fixed as a strip on the tension zone between the column cores and the jacketing. Seven column samples of square cross-section (120 x120) mm at the midsection with overall length of 1250 mm were cast using normal strength concrete (NSC) and having similar longitudinal and transverse reinforcement. The samples were made and tested under axial load at eccentricity equal to 120 mm up to failure. Test parameters were the thickness of jackets (25 and 35) mm and the width of CFRP (0,8, and 12) cm. Column specimens were tested, one of them was reference without any strengthening, and the other specimens divided into two groups (A, and B), and each group included three specimens based on the parameters. Group (A) has UHPFRC jacket thickness 25 mm and CFRP width (0,8, and 12) cm respectively, and group (B) has UHPFRC jacket thickness 35 mm and CFRP width (0,8, and 12) cm respectively. The outcomes of the article show that increasing the thickness of jacket, and width of CFRP lead to increase in the load carrying capacity about (110.5%,168.4%, and 184.2%) for group A, and (157.9%,226.3%, and 263.2%) for group B compared with the reference column due to delay in the appearance of cracks and their distribution. The mid-height lateral displacement of columns was decreased about (66.6%,42.3%, and 35.9%) for group A, and (46.15%,38.46%, and 32.3%) for group B, also the axial deformation of specimens decreased about (71.7%,60.86%, and 55.86%) for group A, and (65.5%,60.5%, and 53.4) for group B compared with the reference column. The ductility of columns that were strengthened with UHPFRC jacket only was increased about (13.67%,19.66%) for thickness(25,35) mm respectively, because of that UHPFRC jacket was contented on steel fibers, and the percentage decrease of ductility was about (5.1%,and 12%) for group (A), (1%,and 9.4%) for group (B) when bonded CFRP in the tension zone with width (8 ,and 12) cm respectively. The results show improvement in the initial and secant stiffness when, increased the thickness of jacket, and width of CFRP because of increase in the size of columns and improvement in the modulus of elasticity. The toughness increase was about (273.97%,301.55%, and 304.5%) for group A, and (453.69%,511.93%, and 524.28%) for group B compared with the reference column because of increase in the size of specimens and delay the appearance of cracks.


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