Statistical insight into the quality of reinforcing steel bars used in construction projects

Abstract

Steel bars are part and parcel of reinforced concrete used in the construction projects, ranging from single family houses to super tall buildings and long span bridges. Maintaining the quality of the steel bars has always been challenging especially in developing countries. Low quality steel bars result in serviceability issues and reduce useful life of structures. This research work is focused on examining and investigating some basic facts about the quality of the steel bars produced in Pakistan. Pakistan being 5th most populous country in the world has huge consumption of steel. Laboratory testing data of steel bars are statistically analysed to have an insight in to the quality of bars. These steel bars were tested over a period of two years, which belong to several real-life projects. Properties like weight per unit length, yield strength, ultimate strength and percentage elongation were mainly analysed. Findings show that out of the stock of 4782 bars, 17.4 % failed to meet the minimum requirements provided by American Society of Testing and Materials (ASTM A615). Quality of grade 60 bars was found better than those of grade 40.

Keywords

• Construction material
• Mild steel bars
• Yield strength
• Elongation
• Ultimate strength