Laboratory Characterization of Cor-Tuf Concrete With and Without Steel Fibers

摘要

Personnel of the Geotechnical and Structures Laboratory, U.S. Army Engineer Research and Development Center, conducted a series of laboratory experiments to investigate the strength and constitutive property behavior of baseline ultra-high-performance composite (Cor-Tuf) concrete with and without steel fibers. A total of 23 mechanical property tests were successfully completed for Cor-Tuf1 and Cor-Tuf2 concrete. The mechanical property tests included hydrostatic compression, unconfined compression (UC), triaxial compression (TXC), unconfined direct pull (DP), uniaxial strain, and uniaxial strain load/constant volume strain loading tests. In addition to the mechanical property tests, nondestructive pulse-velocity measurements and mass properties were obtained on each specimen. The TXC tests exhibited a continuous increase in maximum principal stress difference with increasing confining stress. A compression failure surface was developed from the TXC test results at six levels of confining pressure and from the results of the UC tests. The results for the DP tests were used to determine the unconfined tensile strength of the concretes, which were less than 10% of the unconfined compressive strength. The Cor-Tuf with the steel fibers exhibits slightly greater strength with increasing confining pressure than the Cor-Tuf without steel fibers. Overall, the results from all of the compression tests for both Cor-Tuf concretes were very similar.