Issue 9/98 of the Deutsches Institut fur Bautechnik’s Guideline on ‘Using anchors in nuclear power plants and nuclear installations’ [63] constitutes for the first time what tests are required over and above the General Approval in order to facilitate use of anchors for safety-related attachments in nuclear power plants.

This Guideline contains details of the tests needed to simulate the extraordinary stress situations involved in an earthquake. To prove their suitability, anchors must withstand a monotonic tension load, alternating loads at constant crack widths and varying crack widths at constant loads at a crack width of 1.5 mm. These test loading conditions simulate comprehensively the accidental stresses due to earthquake actions. To obtain the characteristic tension loads, monotonic tensile tests are conducted at an open crack width of 1.0 mm. The characteristic shear strength is determined by alternating shear load tests, in which anchors are exposed to 15 times the alternating shear loads in the direction of the crack. The residual load-bearing strength is then determined by a monotonic shear tension test.

The new edition of the Guideline of June 2010 [67] revised the crack widths. This also allows for the specific crack widths that are expected at the place of use to be used in tests. However, this requires a detailed verification of the characteristic crack widths under accidental actions. An additional section has also been added on testing to determine realistic anchor shifts. Under the DIBt Guideline, anchor shifts are determined by tests in opening and closing cracks at a constant tensile load acting on the anchor and tests at alternating loads on the anchor with the crack opened, varying the crack widths as well as variable alternations of crack widths and loads. To pass these tests, anchors must satisfy a numbers of requirement defined in the DIBt Guideline.