Experimental Tests of the UHPC in Triaxial Compression: Fid-Bau Portal

Experimental Tests of the UHPC in Triaxial Compression

Vogel, Filip / Sovják, Radoslav / Jogl, Marcel

An experimental study of the ultra high performance concrete (UHPC) subjected to triaxial compression is presented in this paper. The examined ultra high performance concrete was developed at the Faculty of Civil Engineering at CTU in Prague from the components locally available in the Czech Republic without using any special mixing technique or curing procedure. The uniaxial compressive strength was determined to be 123 MPa and 149 MPa for cylinders and cubes, respectively. Behaviour of the UHPC in triaxial compression was investigated in two different ways. In the first way cylinders were tested in triaxial chamber. The cylinders were 200 mm high and 100 mm in diameter. The cylinders were tested in triaxial chamber under lateral stresses equaled to 10, 20 and 30 MPa. The second way of testing UHPC in the triaxial compression was a triaxial loading machine where cubes were tested. The size of the cubes was 100 mm. The cubes were tested under the lateral stresses equaled to 15, 30, 60 and 90 MPa. Two equations for both cylinders and cubes showing the strength development were provided using power law regressions. The difference between triaxial strength development of cubes and cylinders was slight. The results obtained in this study were in good agreement with the results gained from the literature. It was experimentally verified that the strength development of the UHPC under different levels of the confinement pressure is not linear and tends to follow the power law function. In addition it was stated that the permissible stress surface of the UHPC falls below the permissible stress surface of the normal strength concretes, especially within the higher confinement pressures.