Theoretical analysis of bond characteristics between steel bars and ultra-high-performance concrete

In order to investigate the bond and anchorage characteristics of steel bars embedded in ultra-high-performance concrete (UHPC), Tepfers’ (1979) thick-walled cylinder theory and elastic mechanics theory were used to establish a theoretical calculation model of bond strength between deformed steel bars and UHPC under the conditions of splitting failure and pullout failure, respectively. The proposed calculation model was verified with a large number of test data from the literature and experiments conducted by the authors. Finally, the anchorage length of deformed steel bars in UHPC was calculated by the centre point method, the check point method and the design specification of normal concrete structure; recommended values of anchorage length are given based on anchorage reliability theory. The research results can provide design basis for design engineers, and are also a useful guideline for the popularisation and application of UHPC materials.