scholarly journals Structural Behavior of Retrofitted Reinforced SCC Continuous Deep Beam With CFRP and Hybrid Techniques

2021 ◽  
Vol 39 (7) ◽  
pp. 1153-1163
Author(s):  
Wisam J. Al -Bdari ◽  
Nabeel A. Al-Bayati ◽  
Ihsan S. Al-shaarbaf

In this research, the results of experimental test of seven reinforced SCC continuous deep beams after being retrofitting by CFRP with different techniques. The main objective of the current research is to investigate the structural behavior in the shear performance and failure modes. The first beam tested up to failure and assumed as reference beam, while remaining six beams firstly loaded with 65% of ultimate load capacity then retrofitted by three systems namely: externally bonded reinforcing (EBR) by CFRP strips, near surface mounted technique (NSM) CFRP rods and the third system was hybrid technique by composite between EBR CFRP strips and NSM CFRP rods. The experimental results show that applying the EBR CFRP strips in a vertical direction improved the loading capacity in comparison with the horizontal direction. On the other hand, the NSM CFRP rods applied in horizontal direction presented higher values in both ultimate loading capacity and final deflection, where the increasing in ultimate load capacity about 43.48%, and the increasing in deflection about 33.5% compared with control beam. Therefore, it can be concluded that applying the hybrid technique is more efficient when the EBR strips and NSM bars applied in the vertical, and the horizontal directions, respectively.

2021 ◽  
Vol 25 (6) ◽  
pp. 91-102
Author(s):  
Aula H. Faeq ◽  
◽  
Ali H. Aziz ◽  

The current experimental investigation is devoted to study the structural capacity of near-surface mounted steel bars strengthened deep beams. Six reinforced SCC deep beam specimens with a dimension of 1400mm x175mm x350mm were tested under Combined Loads of Repeated and Elevated Temperature. The adopted variable includes the type of loading, degree of elevated temperature, and presence or absence of the strengthening by NSM-steel bars. The experimental results show that the ultimate load of B2-R-T20 decreased by about 33% when the applied load changed from monotonic to repeated; also, when the degree of burning increased to (200oC) and (350oC), the ultimate load decreased by 44% and 65% , respectively. The presence of the strengthened NSM-steel bars leads to increase the lateral strength of the tested beams and arrested the diagonal cracks to be widening as a result, the ultimate load capacity increases by (193%-197%) for the samples exposed to elevated temperature, in comparison with reference beams. The adopted strengthened technique proved to be adequate to restore and increase the shear capacity of the tested beams.


2018 ◽  
Vol 162 ◽  
pp. 04016
Author(s):  
Nabeel Al-Bayati ◽  
Bassman Muhammad ◽  
Sarah Sadkhan

Experimental program were carried out to investigate the behavior of self-compacting reinforced concrete deep beams retrofitting with carbon fiber reinforced polymer (CFRP). Six simply supported deep beams were tested under symmetrically two point loads, three beams were tested up to failure without strengthening as a control beams with different shear span to effective depth ratio (a/d) while the other two beams were loaded up to 60% from the ultimate load of control beams for each a/d ratio and then retrofitted by the same configuration of CFRP to study the effect of a/d ratio on the properties of deep beams retrofitted. a/d for tested beams were (0.8, 1, 1.2). Study was focused on determining failure loads, cracking loads, failure modes, load midspan deflection. All the beams had the same compressive strength, overall dimensions and flexural and shear reinforcement. It was concluded that using this retrofitted method is very efficient and a gain in the ultimate load capacity of the deep beams was obtained also the results showed that when a/d ratio increase from 0.8 to 1.2, the ultimate load was decrease by 25% and midspan deflection was increased approximately at all load stages for control and retrofitted beams.


1967 ◽  
Vol 93 (3) ◽  
pp. 259-267
Author(s):  
Marek Janas ◽  
Lance A. Endersbee ◽  
M.L. Juncosa ◽  
K.V. Swaminathan ◽  
A. Rajaraman

2020 ◽  
Vol 857 ◽  
pp. 162-168
Author(s):  
Haidar Abdul Wahid Khalaf ◽  
Amer Farouk Izzet

The present investigation focuses on the response of simply supported reinforced concrete rectangular-section beams with multiple openings of different sizes, numbers, and geometrical configurations. The advantages of the reinforcement concrete beams with multiple opening are mainly, practical benefit including decreasing the floor heights due to passage of the utilities through the beam rather than the passage beneath it, and constructional benefit that includes the reduction of the self-weight of structure resulting due to the reduction of the dead load that achieves economic design. To optimize beam self-weight with its ultimate resistance capacity, ten reinforced concrete beams having a length, width, and depth of 2700, 100, and 400 mm, respectively were fabricated and tested as simply supported beams under one incremental concentrated load at mid-span until failure. The design parameters were the configuration and size of openings. Three main groups categorized experimental beams comprise the same area of openings and steel reinforcement details but differ in configurations. Three different shapes of openings were considered, mainly, rectangular, parallelogram, and circular. The experimental results indicate that, the beams with circular openings more efficient than the other configurations in ultimate load capacity and beams stiffness whereas, the beams with parallelogram openings were better than the beams with rectangular openings. Commonly, it was observed that the reduction in ultimate load capacity, for beams of group I, II, and III compared to the reference solid beam ranged between (75 to 93%), (65 to 93%), and (70 to 79%) respectively.


2018 ◽  
Vol 65 ◽  
pp. 08010
Author(s):  
Je Chenn Gan ◽  
Jee Hock Lim ◽  
Siong Kang Lim ◽  
Horng Sheng Lin

Applications of Cold-Formed Steel (CFS) are widely used in buildings, machinery and etc. Many researchers began the research of CFS as a roof truss system. It is required to increase the knowledge of the configurations of CFS roof trusses due to the uncertainty of the structural failures regarding the materials and rigidity of joints. The objective of this research is to investigate the effect of heel plate length to the ultimate load capacity of CFS roof truss system. Three different lengths of heel plate specimens were fabricated and subjected to concentrated loads until failure. The highest ultimate capacity for the experiment was 30 kN. The results showed that the increment of the length of the heel plate had slightly increased the ultimate capacity and strain. The increment of the length of the heel plate had increased the deflection of the bottom chords but decreased the deflection of the top chords. Local buckling of top chords adjacent to the heel plate was the primary failure mode for all the heel plate specimens.


2011 ◽  
Author(s):  
Zongfen Zhang ◽  
Chris Chen ◽  
Gregory Zywicki ◽  
Brad Blaski ◽  
James Blenman

2010 ◽  
Vol 168-170 ◽  
pp. 632-636 ◽  
Author(s):  
Xia Ping Liu ◽  
Shu Tang ◽  
Chun Hui Tang ◽  
Zuo Yong Yang ◽  
Zuo Sun

This paper deals with the ultimate load capacity test on 14 short columns of separation concrete-filled steel tubes (CFST) which are subjected to the eccentric compression on separate side. The experimental parameters include the separation ratio and the eccentricity ratio. The result shows that the separation ratio and the eccentricity ratio will influence the load capacity of the components of the concrete-filled steel tubes which are subjected to the eccentric compression. The confinement of steel tubes to core concrete will be continuously weakened and the ultimate load capacity of the components will be decreased obviously with both the separation ratio and the eccentricity ratio increasing gradually.


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