MECHANICAL PROPERTY ASSESSMENT AND EVALUATION OF LOCALLY MANUFACTURED AND IMPORTED RE-BARS IN LIGHT OF THE ETHIOPIAN STANDARD
Author/s
KELKIYAS ALEMU, KASSAHUN ADMASSU (PHD)
Abstract
Reinforcing concrete structure is the most practicable measure to overcome the limitations in plain concrete. Reinforcement bars are provided considering all tension inducing loads on the structure most of the time. Accredited material laboratories and authenticated product certificates are used to check the quality of re-bars. Thus, the main objective of the research is to assess and evaluate the mechanical properties of locally produced re-bars in light of the Ethiopian Standard and with those imported for the same purpose in perspective. In order to achieve the stated objective, the pilot survey conducted identified many issues related to the quality of re-bars at government projects and laboratories in Ethiopia. Having all those issues in mind and reviewing research done so far triggered the idea of mechanical property investigation on locally manufactured and imported re-bars, in light of the Compulsory Ethiopian Standard. To start with, five local and imported re-bar products were selected. Laboratory tests were conducted on diameter 8, 10, and 12mm re-bars from the chosen five local and those imported sources. The obtained test results were corroborated with those collected from service rendering laboratory archival documents. Both laboratory and archival test results were analyzed in reference to the compulsory mentioned standard focusing on the failure percentages of the governing mechanical parameters of yield strength, ultimate tensile strength, and elongation. The imported products and the local ones are compared and analyzed to see whether there is a significant difference between the two. The finding revealed that there are both local and imported products in the market which could not fulfill the standard requirements. Specifically, both the local and imported 8 and 12 mm diameter re-bars failed in mainly the elongation requirement. Therefore, it is concluded that there is a quality issue on re-bars available in the local market when evaluated against the Ethiopian Standard. The quality controlling system both on locally manufactured and those imported re-bars seem too loose to inspect re-bar products in the construction materials market. Thus, stringent standard sanctions should be in place to safe-guard the industry.