Investigating the quality of ethiopian steel reinforcing bars through comprehensive analysis

The fast economic growth, urbanization, and industrialization of Ethiopia led to the requirement for the establishment of various infrastructures and many residential building constructions consuming different types of materials. Reinforced steel bar is one of the most consumed construction materials in Ethiopia. The demand for reinforced steel bars in Ethiopia is satisfied by the local production and international market. However, most people lack trust to the use local products without justified reasons. This investigation work was done to evaluate the performance of the locally produced rebar concerning the Compulsory Ethiopian Standard (CES) to develop trust in contractors and consultants of different projects. A Compulsory Ethiopian Standard (CES) is an Ethiopian standard that has been prepared under the direction of the Technical Committee for Concrete and Concrete Products and published by the Ethiopian Standards Agency (ESA). Experimental works were done on rebar of grades B400BWR and B500BWR with different diameters collected from four different factories. The collected samples were investigated based on their yield strength, ultimate tensile strength, elongation, hardness, chemical composition, and microstructure formation of the product. The yield strength, ultimate tensile strength, and elongation of the rebar were analyzed based on the tension test results obtained from the 2000 KN Universal Testing Machine (UTM), and the chemical composition analysis was done using the Spark Emission Spectrometer Analyzer. The micro-hardness test was done using the Vickers Hardness Tester with 3kgf and 15-s dwell time at a 0.5 mm gap along the cross-section of the rebar. Microstructure analysis is done using EDX scanning electron microscope (SEM) and optical microscopy with different magnifications and resolutions on the cross-section of the rebar. From the tested samples one sample failed from B400BWR to achieve the minimum required yield strength of 400 MPa stated by CES 101, 2017. Samples of B500BWR satisfy all the requirements stated by the standard even if there is an increment up to 41 % beyond the minimum requirement.