| The bond strengths of uncoated and epoxy-coated high relative rib area (ROne hundred and forty beam-splice specimens are tested to study the effects of bar placement, concrete properties, bar size and deformation pattern, transverse reinforcement, and epoxy coating on splice strength. The test results are combined with the previous results for analysis. The combined results include tests for No. 5, No. 8, and No. 11 bars with RThe results show that the top-bar behavior of high RThe test results indicate that concrete containing stronger coarse aggregate provides higher splice strength. For specimens with bars confined by transverse reinforcement in the splice region, concrete with a higher coarse aggregate content produces higher splice strength. For bars not confined by transverse reinforcement, the 1/4 power of concrete compressive strength better characterizes the effect of concrete strength on splice strength than the traditionally used 1/2 power. For bars confined by transverse reinforcement, the 3/4 power of concrete compressive strength better characterizes the effect of concrete strength on the contribution of transverse reinforcement to splice strength than the 1/2 power.The results of 62 matched pairs of uncoated and epoxy-coated splice specimens show that epoxy coating is less detrimental to the splice strength of high RThe development/splice strength design criteria developed in this study accurately represent the effects of bar size, relative rib area, transverse reinforcement, and concrete strength. The new design criteria, which incorporate a reliability-based strength reduction factor, are more economical and have a higher safety margin than the design criteria in ACI 318-95.Under reversed cyclic loading, high R... |
