A COMPARISON OF BOND PERFORMANCE OF CONCRETE REINFORCED WITH REINFORCEMENTS FROM DIFFERENT MANUFACTURERS

Abstract

The transfer of stress from a deformed bar to the concrete is achieved by mechanical locking of the steel into the surrounding concrete. This interfacial bond strength between steel and the surrounding concrete is an important factor influencing the strength and durability of reinforced concrete structure. This paper presents the result of investigation conducted to find out the bond performance of reinforcement from different manufacturer. 12 mm and 16 mm diameter steel specimens from five different manufacturers were used for this investigation. Tensile properties and pull out test were conducted. The results showed that: (i) all the steel specimens substantially met the minimum requirement specified by relevant standards for both 12 mm and 16 mm diameters, (ii) Bond performance of locally-made was found to be better than the imported ones for 12 mm diameter, but for 16 mm diameter, imported steel showed a better bond performance than the locally made ones, (iii) All the steel specimens exhibited splitting failure, (iv) the lowest values of slippage were exhibited by a locally-sourced steel specimens, and (v) bond stresses obtained from this investigation for both 12 mm and 16 mm diameter bars are structurally adequate.