[Weld shear Test Apparatus and Methods]
1.As the welds in welded wire reinforcement contribute to the bonding and achorage value of the wires in concerte,it is imperative that the weld acceptance tests be made in a jig that will stress the weld in manner similar to which it is stressed in concrete.In order to accomplish this the vertical wire in the jig must be stressed in an axis close to its center line.Also the horizontal wire must be held closely to the vertical wire,and in the same relative position,so as to prevent rotation of the horizontal wire.When the welded wire reinforcement is designed with different wire sizes,the larger diameter wire is the'' vertical wire'' when teste(see fig,15).
2.Fig 1 shows the details of a typical testing jig together with two anvils which make it possible to test welds for wire up to 15.88 mm[5/8 in.] in diameter.This testing jig can be used in most tension testing machines and should be hung in a ball and socket arrangement at the center of the machine.This,or a similarly effective fixture designed on the same prinicple,is acceptable.
3. Test secimens should be inserted through the notch in the avil using the smallest notch available in which the vertical wire will fit loosely.The vertical wire shall be in contact with the surface of the free ratating rollers while the horizontal wire shall be supported by the anavil on each side of the slot.The bottom jaws of the testing machine shall grip the lower end of the verical wire and the load shall be applied at a rate of stressing not to exceed 689 MPa/min [100 000 psi/min].
