BEHAVIOUR OF HIGH STRENGTH CONCRETE UNDER COMBINED BENDING AND COMPRESSION

This paper describes the development of a computerized closed-loop testing facility for experimentally obtaining the stress-strain behaviour of high strength concrete specimens under combined compression and bending. Using this closed-loop computerized testing facility, 240 test specimens were tested to failure. The test variables were geometry or shape of specimens, age at testing and the concrete strength. The computerized closed-loop testing facility assures that the vertical load is at the edge of the central core during the test, thus ensuring zero strain at one extreme face. This mimics the strain distribution in the compression zone. The effect of cross-section shape and the strength of concrete on the compression zone is the most significant result obtained during the tests. 1