Document Type : Research Paper
Authors
1 Ashur University College - Iraq
2 Civil Engineering Department, University of Technology - Iraq
Abstract
The main objectives of this study are: encouraging the production and use of self-compacting concrete, use of materials which are lightweight, easy to use, and highly efficient in the retrofitting of reinforced concrete buildings. Six deep beams specimens (L= length of 1400mm, h= height of 400mm, and b= width of 150mm) were cast using self-compacting concrete. The location of the openings is in the middle of assumed load path. Five patterns were adopted to arrange carbon fiber reinforced polymer (CFRP) strips. The cylinder compressive strength of the concrete was approximately equal for all beams and was about (44 MPa) at 28 days age. All the beams have the same steel reinforcement for shear and flexure. There have been many tests for fresh and hardened concrete. The reinforced concrete deep beams were tested up to (60%) of the ultimate load of control beams to simulate degree of damage, and then released the load. After that,the beams were retrofitted using (CFRP) strips, and then the beams were tested to failure. The study was focused on determining the vertical mid-span deflection, ultimate load, the load that causes first shear and flexural cracks, and mode of failure. Theresults showed that, the best increase in the ultimate failure load was (27.27%) and achieved using the inclined strips pattern and the pattern of vertical and horizontal strips together. Reduction in the deflection values for the retrofitted beams compared to the control beam by about (12-13%) due to restrictions imposed by CFRP strips and the epoxy.
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