scholarly journals Design and Testing of Various Ceiling Elements Made of Carbon Reinforced Concrete

Proceedings ◽  
2018 ◽  
Vol 2 (8) ◽  
pp. 543 ◽  
Author(s):  
Alexander Schumann ◽  
Sebastian May ◽  
Manfred Curbach

In this paper the design and recalculation of new type ceiling elements made of carbon reinforced concrete (CRC) is described. With the use of the high-potential composite material carbon reinforced concrete, structures can be, compared to conventional steel reinforced concrete (RC), designed and manufactured slimmer and lighter. Because of this and the increased sustainability of ceiling elements made of CRC a noteworthy amount of concrete can be saved. To show the potential of CRC elements, four different structures for various fields of application are shown. The first ceiling element, which will be introduced, fits perfectly for the use in multi-storey car parks because of the high resistance of the carbon fibers against corrosion. Another CRC structure in this paper was created in a research project as a demonstrator to show the potential of the newly developed concrete mixture for CRC. To prove the ability of this new developed concrete, large-scale CRC I-beams were produced in a precast concrete factory. The third ceiling element was designed and manufactured in form of a shell to combine the high strength composite material with an improved design for ceiling elements. The last introduced CRC element was developed as demonstrator in another research project and was designed in form of a ribbed slab.

Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 6860
Author(s):  
Jun Wang ◽  
Yuxin Duan ◽  
Yifan Wang ◽  
Xinran Wang ◽  
Qi Liu

To investigate the applicability of the methods for calculating the bearing capacity of high-strength steel-reinforced concrete (SRC) composite columns according to specifications and the effect of confinement of stirrups and steel on the bearing capacity of SRC columns. The axial compression tests were conducted on 10 high-strength SRC columns and 4 ordinary SRC columns. The influences of the steel strength grade, the steel ratio, the types of stirrups and slenderness ratio on the bearing capacity of such members were examined. The analysis results indicate that using high-strength steel and improving the steel ratio can significantly enhance the bearing capacity of the SRC columns. When the slenderness ratio increases dramatically, the bearing capacity of the SRC columns plummets. As the confinement effect of the stirrups on the concrete improves, the utilization ratio of the high-strength steel in the SRC columns increases. Furthermore, the results calculated by AISC360-19(U.S.), EN1994-1-1-2004 (Europe), and JGJ138-2016(China) are too conservative compared with test results. Finally, a modified formula for calculating the bearing capacity of the SRC columns is proposed based on the confinement effect of the stirrups and steel on concrete. The results calculated by the modified formula and the finite element modeling results based on the confinement effect agree well with the test results.


2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Alexander Bulkov ◽  
Michail Baev ◽  
Igor Ovchinnikov

The influence of reinforcing steel corrosion on the durability of reinforced concrete structures of transport structures and the degree of knowledge of this problem is considered. It is specified that the protection of reinforcing steel from corrosion is not able to completely replace the correct design and use of high-strength concrete. But it is able to extend the life of reinforced concrete structures. It is noted that corrosion of the reinforcement leads to a decrease in the structural strength due to wear and tear and by a third of the period of operation of reinforced concrete structures, as a result of which transport structures collapse. As an example of the detrimental effect of corrosion of reinforcing steel on the durability of transport structures, examples of accidents of bridges and overpasses caused by this type of corrosion are given. As a result, a conclusion is drawn on the advisability of ensuring a sufficient level of corrosion protection of reinforcing steel to achieve the required durability of reinforced concrete structures of transport structures. The types and causes of corrosion processes in reinforcing steel reinforced concrete structures are described. The compositions and technologies of anticorrosive protection are examined and analyzed. Comparison of the compositions of anticorrosive protection of reinforced concrete structures is carried out according to the following criteria: consumption, density, viability, curing temperature and the number of components of the composition. A comparison of anti-corrosion protection technologies is carried out on the basis of the following indicators: line dimensions, productivity and consumption of energy resources. A comparison is also made of the cost of using various anti-corrosion protection technologies. Based on the data obtained, the advantages and disadvantages of the considered compositions and technologies of corrosion protection are determined. As a result, the most effective and technologically advanced method of corrosion protection of steel reinforcement of reinforced concrete structures of transport structures is selected.


Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4210 ◽  
Author(s):  
Viviane Adam ◽  
Jan Bielak ◽  
Christian Dommes ◽  
Norbert Will ◽  
Josef Hegger

Many older bridges feature capacity deficiencies. This is mainly due to changes in code provisions which came along with stricter design rules and increasing traffic, leading to higher loads on the structure. To address capacity deficiencies of bridges, refined structural analyses with more detailed design approaches can be applied. If bridge assessment does not provide sufficient capacity, strengthening can be a pertinent solution to extend the bridge’s service lifetime. For numerous cases, applying an extra layer of textile-reinforced concrete (TRC) can be a convenient method to achieve the required resistance. Here, carbon fibre-reinforced polymer reinforcement together with a high-performance mortar was used within the scope of developing a strengthening layer for bridge deck slabs, called SMART-DECK. Due to the high tensile strength of the carbon and its resistance to corrosion, a thin layer with high strength and low additional dead load can be realised. While the strengthening effect of TRC for slabs under flexural loading has already been investigated several times, the presented test programme also covered increase in shear capacity, which is the other crucial failure mode to be considered in design. A total of 14 large-scale tests on TRC-strengthened slab segments were tested under static and cyclic loading. The experimental study revealed high increases in capacity for both bending and shear failure.


2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Xiaolong Zhang ◽  
Bingchuan Duan ◽  
Chengzhi Wang ◽  
Duoyin Wang

In this study, a three-dimensional finite element model was established to simulate the dynamic response of a large-scale steel-reinforced concrete composite high-pile wharf with a rock-socketed steel sheath. The model is based on the second phase of the Chongqing Orchard Harbor structure project in conjunction with the project “Research on the mechanism of interface damage and energy dissipation of the structure of the large-scale steel-reinforced concrete composite high-pile wharf in inland waters.” The stiffness of frame wharf is studied from the perspective of modal and transient dynamic analysis of structural dynamics. The distribution of the low-order modal frequency is more uniform. With the increase of the order, the modal frequency of the structure shows a periodical jump. The overall stiffness of the frame structure is larger with the steel sheath, and the longitudinal stiffness is less than the transverse stiffness. Under the action of transverse impact load, the members and joints of the steel-concrete structure exhibit synchronous mechanical response characteristics in the time domain. The peak values of displacement and stress of the structural joints occur 0.05 s after the peak value of the load-time history, and the peak value of reverse response of force occurs at 2.3 s, which is markedly smaller than the peak value of the response of load direction. Reducing the local positional stiffness of the load point is beneficial to improve the stress of the entire structure. The weak links of the frame structure appear at the joints of the members. Because of the hoop action of the steel sheath, the stress of the reinforced concrete pile core is more uniform. The peak value of the equivalent stress of the steel sheath member is generally larger than that of the reinforced concrete pile core, and the stress is highly concentrated at the joints of the steel tube longitudinal and transverse braces.


2011 ◽  
Vol 466 ◽  
pp. 121-130 ◽  
Author(s):  
Josef Hegger ◽  
Christian Kulas ◽  
Michael Horstmann

In the last 30 years, façade-panels made of steel-reinforced concrete have become less attractive for architects and clients. Due to the metallic reinforcement, the insufficient concrete covers of former design code generations and hence the material-dependent corrosion, many cases of damage occurred. Using technical textiles for a new composite material, Textile Reinforced Concrete (TRC), it is possible to produce concrete structures which are not vulnerable to corrosion. The presented ventilated large-sized façade elements and self-supporting sandwich panels exemplify the capability of TRC. In the paper, applied materials are characterized and the production process of tailor-made textile reinforcements as well as the load-bearing behavior of the members is described.


2013 ◽  
Vol 351-352 ◽  
pp. 359-362 ◽  
Author(s):  
Xin Wang

This paper, the mechanics characteristic of T-shaped section steel reinforced concrete column under low period repeated loading by using large-scale finite element analysis software ABAQUS was analyzed, combined existing research, the influence of the performance of ductility under different steel ratio and axial compression ratio was studied, we concluded that the T-shaped section steel reinforced concrete column has the very good ductility performance, and put forward the axial compressive ratio limit under the different parameters, and to provide the reference for future research and application.


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