DR. MWERO JOHN NYIRO

Steel reinforcement bars are a key component in reinforced concrete and are mainly employed to carry tensile stresses since concrete on its own is weak in tension. Sometimes these bars are wrongly bent, straightened and re bent, resulting in the altering of their original characteristics. Some of such steel has been used and some condemned as unfit for reinforcing purposes. This paper reports on the behavior of these reworked bars in reinforced concrete. In the investigation, test concrete beams built using reworked bars were built, cured and tested in bending to ultimate failure. Load-deflection relationship, beam side strains, cracking patterns and ultimate loads were investigated. Some tensile tests were also carried out on the reinforcement bars to give an indication of the behavior of the reinforcement steel, both normal and reworked. Beams built using reworked bars were found to be stiffer in the plastic range of the tensile reinforcement bars. From these results it was found that reworked reinforcement bars could be used for reinforcing concrete if the design formulae provided in the design codes were modified to cater for the slight changes in the properties of such steel.