Comparative Investigation of the Tensile Strength of Steel Bars With and Without Couplers

Abstract

Connection in reinforced concrete is unavoidable due to limited length of steel. As known the maximum length of steel 12 metres and used for beams, columns, plates, foundations, etc. Sometimes several buildings use long spans between column to column for architecture causes longer steel needs. If spans are more than 12 metres the steels should be connected by welding, coupler drates, and other parts of connection. Coupler drates one of the most popular connection and it is easy to make connection between steels in the reinforcement concrete. This research aims to determine the behaviour of steels when they were tensioned at testing machine either full steel bar and connected steel bar by coupler drates. The testing was conducted at the materials laboratory the references for testing are Indonesian standards for testing materials like SNI - 2052 - 2017, SNI - 8389 - 2017 and SNI - 07 - 0408 - 1989. The type of steel bars for testing are drate steels of diameters 25 mm and 32 mm and the type of test is tensioning test. The results of testing for normal steel bar of D- 25 mm is 619.3 MPa and D-32 mm is 636 MPa respectively and steel bar with coupler drates for D- 25 mm is 428 MPa and D-32 mm is 522.5 MPa respectively. It means tension strength of D-25 mm coupler drates decreases 30.88 % and tension strength of D-32 mm decreases 17.84 % as compared with steel bars.