Concrete axial compressive strength with different loading directions and boundary conditions

ABSTRACT In this work the axial compression strength of 10 cm side cubic specimens of three concrete with characteristic strengths of 30 MPa, 50 MPa, and 65 MPa were analyzed experimentally. The compression load was applied in the same direction and perpendicular to the casting direction of the cubic specimens. The fracture mode was analyzed when the boundary conditions of the tests were modified. In the first boundary condition, grease was applied between the specimens and the machine’s plate to minimize friction. In the second boundary condition, 3 mm steel plates were glued to the sides of the specimens to maximize friction. One of the main results was that the strength change with the load direction. For the 50 MPa concrete, the compression strength was 16% higher when it was parallel to the casting direction than when it was perpendicular. With respect to the boundary conditions, it is found that when the specimen sides were restricted, there was an increase in the compression strength, independently of the concrete class. These results may be a potential contribution for the development of the reinforced concrete project and its structural analysis.