Shear Characteristics of Large Anchorage System

Large anchorage system with anchor bolt exceeding 50mm of bolt diameter or effective embedment depth deeper than 635mm is usually used in nuclear concrete structure, but shear design criteria for large anchorage system is not clearly addressed by ACI 349-06 Appendix B (ACI 349, 2006). Therefore, to find out the shear characteristics of large anchorage system, 24 prototype specimens were manufactured and tested by ASTM E 488. Test variables are anchor bolt diameter( do= 63.5, 76.2, 88.9mm), effective embedment depth ( hef= 635, 762mm), and edge distance( c1=381, 508, 762mm). Concrete compressive strength was constant.( f'c= 38MPa) and anchor bolt(steel), high strength anchor bolts of ASTM A 540 class B were used. Test results as follows : Shear strengths calculated by ACI 349-06 and CCD method overestimate shear strength of large anchorage system exceeding 50mm of bolt diameter(do ). As the edge distance(c1 ) increased, the shear breakout fracture force increases. Anchor bolt diameter(do ) and effective embedment depth(hef ) have little influence on shear strength of large anchorage system, but edge distance(c1 ) is more related with shear strength of large anchorage system.