Aproximación analítica de la superficiede interacción de secciones de hormigón armado sometidas a esfuerzos de flexión esviada

Analytical approach for failure surface of RC sections under axial load and biaxial bending

This paper proposes an analytical approach for failure surface calculation of rectangular RC cross-sections with symmetrically distributed reinforcement under axial load and biaxial bending. This analytical expression is valid for compressive strength of concrete between 25 and 80 MPa. The failure surface is obtained by means of reference generatrices on two directrices corresponding to two known axial loads and on the maximun and minimun axial capacity of the section. The proposed expression has been checked with results obtained from experimental tests and from a numerical model. Through this approach it is possible to verify section capacity and to design the reinforcement with enough accuracy for the professional practice. It is easy to use and may be applied to an important percentage of reinforced concrete columns in buildings.