Structural architect-engineer collaboration. Julio Martínez Calzón explains what stressability is, duration: 11´ 54´´, master in Spanish and master subtitled in English. Julio Martínez Calzón is a civil engineer, bridge and large structure designer a lecturer in Mixed Structures at the Polytechnic University of Madrid’s School of Engineering and the author of Puentes, Estructuras, Actitudes (2006).