Reliability of masonry anchorage

Anchor bolts are commonly used to connect structural or mechanical elements to masonry to resist the tension and shear load arising from wind, earthquake, and gravity loads. Despite the availability of design provisions for anchorage to masonry, the behavior of anchor bolts in masonry is not well understood. In particular, there is almost no data on anchor bolts embedded in the top of masonry walls, where the anchoring element is proximate to a free edge, loaded either in tension, in shear or both.;A database of masonry anchorage was developed from existing test data and the results of this research Strength Design Method in MSJC 2005 Code and Concrete Capacity Design Method (Appendix D of ACI 318-02) were used to evaluated the available test data. Using Monte Carlo techniques, the reliabilities of masonry anchor bolts designed using the MSJC 2005 Code and CCD Method were created.;In this research project, an experimental program was conducted to investigate the behavior of anchor bolts embedded in the tops of fully grouted concrete and clay masonry walls under different loading conditions. The variables studied in the testing program included grout extent, bolt diameter, loading type, bolt type, and edge distances. Results indicated that the tensile capacity of anchor bolts in partially grouted CMU walls decreased as compared to fully grouted specimens. The tensile and shear capacity of L-shaped bolts increased with increasing bolt diameter. Headed anchor bolts loaded in shear also exhibited an increase in strength with diameter. The tensile capacity of headed bolts decreased with increasing diameter for failure modes involving masonry, not steel failure. When steel governed the failure, there was no difference for the shear strength of anchors under in-plane shear and out-of-plane shear loading. For anchor bolts in tension, when masonry governed the failure, the tensile capacity of headed and L-shaped anchor bolts with 5/8-in diameter was close while the average test load of ½-in headed bolt was 32 percent higher than that of L-shaped bolt. The effect of edge distance was insignificant for ½-in diameter of headed and L-shaped anchor under shear loading, when steel governed the failure.