Stress-strain behaviour of steel bars with long nut connection

The reinforcement of reinforced concrete always needs a connector. In order to reduce the overlapping length, the long nuts are used as steel bar connector. The tensile experimental test was obtained to find out the value of yield stress, ultimate tensile strength, elongation and ductility which can be achieved by steel bar long nut connection. The test was using UTM machine instrument which connected to the computer, thus stress-strain curve is obtained. The curve shows the values of elastic, plastic, strain hardening until ultimate tensile strength region, value of yield stress Fy, and ultimate tensile strength Fu. The result of tensile tests how's that the yield stress value of steel bar with long nut connection has the same value with the steel bar without connection. The steel bars with long nut connection can achieve yield stress about 330 MPa, ultimate tensile strength about 340 MPa and strain value about 5%-6%, it is lower than the steel bars without connection. It indicates that long nut can be used as a connector tool in overlapping steel bar connection.