BEHAVIOR OF STEEL FIBROUS CEMENT BASED COMPOSITES IN THE ANCHORAGE ZONES OF PRESTRESSED BRIDGES

摘要

Behavior of Steel Fibrous Cement Based Composites (SFCBC) in the anchorage zones of prestressed bridges was investigated. The cylindrical compressive strength of the Self-compacting and Self-leveling composite was 160MPa. Three series of prismatic specimens were tested for plain concrete and for SFCBC at volume fractions of fibers 1.5 % and 3.0 %. The specimens were investigated under different concentration ratios of strip loading. The results of these tests showed that the ultimate strength of the SFCBC specimens was approximately twice that of ordinary concrete (C60) with the same size and reinforced with stirrups. Therefore, SFCBC has good possibility to replace the traditional rebars in the anchorage zones of prestressed bridges. This composite has different behavior than the traditional concrete e.g. crack formation, failure criteria, effective strength and angle of friction. A vertical crack on the centerlinc occurred while wedge developed under the loading platen. In contrast to ordinary concrete, the cracks could not reach to the bottom of the blocks. Upper-bound plasticity solutions were utilized for the modeling of bearing capacity of SFCBC. Calculations and the test results were compared. The predictions of this method are good enough to estimate the bearing capacity of SFCBC in the anchorage zones of prestressed bridges.