The Use of Recycled Steel Bars as Shear Reinforcement Swimmer Bars in Reinforced Concrete Beams
Moayyad M. Al-Nasra
Dr. Moayyad Al-Nasra, Professor, Civil Engineering Department, Applied Science University, Amman, Jordan. This research project is sponsored by the Applied Science University, Amman, Jordan.
Manuscript received on 15 December 2015 | Revised Manuscript received on 25 December 2015 | Manuscript Published on 30 December 2015 | PP: 42-47 | Volume-5 Issue-2, December 2015 | Retrieval Number: B4337125215/15©BEIESP
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© The Authors. Blue Eyes Intelligence Engineering and Sciences Publication (BEIESP). This is an open access article under the CC-BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)
Abstract: The discarded steel reinforcement bars can be either sent to steel plant to be melted and reproduced, or reused as steel reinforcement again. The main sources of the recycled steel bars are the demolished structures, damaged bars or collapsed structures. There is little evidence to trust the use of the recycled steel bars as a replacement of new steel bars. Engineers often question the safety of the structures built with recycled steel bars. In order to address the concern of the engineers, the recycled bars must be evaluated and categorized and eventually given an equivalent new bar label. Additional factor of safety could be used for uncertainty. In this study the recycled steel bars are used as spliced swimmer bars for shear reinforcement in reinforced concrete beams. The used bars in this study are classified as class-A recycled bars. There are several alternatives to the traditional stirrups in reinforced concrete beams. This study focuses on providing other options other than the stirrups. Due to the unsafe mode of shear failure in reinforced concrete beams, designers may find themselves reluctant to use higher factor of safety. Shear failure in reinforced concrete beams is one of the most undesirable modes of failure due to its rapid progression. This sudden type of failure made it necessary to explore more effective ways to design these beams for shear. The cost and safety of shear reinforcement in reinforced concrete beams led to the study of other alternatives. In this study two different types of shear reinforcements are used to study the effect of each type of shear reinforcement on the shear performance of reinforced concrete beams. The first type is reinforced by traditional stirrups, while the other type is reinforced by spliced swimmer bars. Two beams were prepared with spliced swimmer bars; the first is made from recycled steel bars, and the other is made from brand new bars. The beam made from recycled spliced swimmers is compared with the other two beams. Beam shear strength as well as beam deflection are the main two parameters considered in this study. The swimmer bar system is a new type of shear reinforcement. Splicing swimmer bars concept is a solution to the welding problem associated with old types of swimmer bars. Special shapes of swimmer bars are used for in this study such that the swimmer bars are spliced with the longitudinal flexural bars. Regardless of the number of swimmer bars used in each inclined plane, the swimmer bars form plane-crack interceptor system instead of bar-crack interceptor system when stirrups are used. The results of the three tested beams will be presented and discussed in this study. Also the deflection of the beams due to the gradual applied load is monitored and discussed. Cracks will be monitored and recorded during the beam test as the applied load increases.
Keywords: Deflection, Shear, Stirrup, Swimmer Bars.
Scope of the Article: Concrete Engineering