Bearing Strength of Concrete Blocks

The problem of end bearing in a post-tensioned concrete beam may be idealized and simplified to the problem of a circular cylindrical or a square prismatic concrete block with a longitudinal cable duct loaded by two circular or square punches applied on the cable duct at both ends. Bearing capacity solutions for the idealized problem were presented recently. Good experimental verifications of the solutions were available for the special case of concrete blocks with eccentricity but without cable duct. No suitable experimental data were available, however, for concrete blocks with both punch eccentricity and cable duct. The purpose of this note is to test specimens with variations of duct diameters and eccentricities with both plain and random wire reinforced concrete. The test results are presented and compared with the theoretical linear elastic and perfectly plastic solutions.