SECTION 1037

SHEAR CONNECTORS

1037.1  Scope.  This specification covers the requirements for stud-type shear connectors and weldability qualification.

1037.2  Material.  Studs shall be in accordance with AASHTO M 169 for cold drawn carbon steel bars Grades 1015, 1017 or 1020, either semi- or fully-killed.  If flux retaining caps are used, the steel for the caps shall be of a low carbon grade suitable for welding and shall be in accordance with ASTM A 109.  The flux for welding shall be self-contained either in the base of the stud or in the ferrule and automatically applied in the welding operation.  A ferrule of heat resistant ceramic or other suitable material shall be used with each stud, and the ferrule shall be composed of material, which is not detrimental to the welds, does not cause excessive slag and has sufficient strength to withstand thermal or structural shock.

1037.3   Qualification Procedure.   The procedure for weldability tests to qualify shear connector studs for welding under shop or field conditions shall be as follows.  Such tests may be performed by a university, independent laboratory or by other approved testing agencies. The tests shall be made on each type and size of stud.  The agency performing the tests shall submit to the manufacturer of the stud a certified report giving procedures and results for all tests, including the information listed under Sec 1037.9.

1037.4   Duration of Qualification.   Qualifications will be considered valid until the manufacturer makes a change in the base of the stud, the flux or the arc shield, which affects the welding characteristics.

1037.5  Preparation of Specimens.

1037.5.1  Test specimens shall be prepared by welding representative studs to the center of square specimen plates, 1/2 to 3/4 inch thick, in accordance with ASTM A 36.  At the option of the manufacturer, several studs may be welded to a large plate and the specimen plates cut of a size suitable for test equipment used.  Studs shall be welded with power source, welding gun and control equipment as recommended by the manufacturer.  Welding voltage, current and time shall be measured by suitable instrumentation and recorded for each specimen.  Lift and plunge shall be at the optimum setting as recommended by the manufacturer.

1037.5.2  Studs shall be of uniform quality and condition, free from laps, fins, seams, cracks, twists, bends or other injurious defects.  The finish shall be as produced by cold drawing, cold rolling or machining.  The overall height after welding will be shown on the plans.  The size of studs with allowable tolerance shall be as follows.